/* * Copyright (c) 2002-2007 Niels Provos * Copyright (c) 2007-2012 Niels Provos and Nick Mathewson * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include "event2/event-config.h" #include "evconfig-private.h" #ifdef _WIN32 #include #include #include #endif #ifdef EVENT__HAVE_VASPRINTF /* If we have vasprintf, we need to define _GNU_SOURCE before we include * stdio.h. This comes from evconfig-private.h. */ #endif #include #ifdef EVENT__HAVE_SYS_TIME_H #include #endif #ifdef EVENT__HAVE_SYS_SOCKET_H #include #endif #ifdef EVENT__HAVE_SYS_UIO_H #include #endif #ifdef EVENT__HAVE_SYS_IOCTL_H #include #endif #ifdef EVENT__HAVE_SYS_MMAN_H #include #endif #ifdef EVENT__HAVE_SYS_SENDFILE_H #include #endif #ifdef EVENT__HAVE_SYS_STAT_H #include #endif #include #include #include #include #ifdef EVENT__HAVE_STDARG_H #include #endif #ifdef EVENT__HAVE_UNISTD_H #include #endif #include #include "event2/event.h" #include "event2/buffer.h" #include "event2/buffer_compat.h" #include "event2/bufferevent.h" #include "event2/bufferevent_compat.h" #include "event2/bufferevent_struct.h" #include "event2/thread.h" #include "log-internal.h" #include "mm-internal.h" #include "util-internal.h" #include "evthread-internal.h" #include "evbuffer-internal.h" #include "bufferevent-internal.h" /* some systems do not have MAP_FAILED */ #ifndef MAP_FAILED #define MAP_FAILED ((void *)-1) #endif /* send file support */ #if defined(EVENT__HAVE_SYS_SENDFILE_H) && defined(EVENT__HAVE_SENDFILE) && defined(__linux__) #define USE_SENDFILE 1 #define SENDFILE_IS_LINUX 1 #elif defined(EVENT__HAVE_SENDFILE) && defined(__FreeBSD__) #define USE_SENDFILE 1 #define SENDFILE_IS_FREEBSD 1 #elif defined(EVENT__HAVE_SENDFILE) && defined(__APPLE__) #define USE_SENDFILE 1 #define SENDFILE_IS_MACOSX 1 #elif defined(EVENT__HAVE_SENDFILE) && defined(__sun__) && defined(__svr4__) #define USE_SENDFILE 1 #define SENDFILE_IS_SOLARIS 1 #endif /* Mask of user-selectable callback flags. */ #define EVBUFFER_CB_USER_FLAGS 0xffff /* Mask of all internal-use-only flags. */ #define EVBUFFER_CB_INTERNAL_FLAGS 0xffff0000 /* Flag set if the callback is using the cb_obsolete function pointer */ #define EVBUFFER_CB_OBSOLETE 0x00040000 /* evbuffer_chain support */ #define CHAIN_SPACE_PTR(ch) ((ch)->buffer + (ch)->misalign + (ch)->off) #define CHAIN_SPACE_LEN(ch) ((ch)->flags & EVBUFFER_IMMUTABLE ? \ 0 : (ch)->buffer_len - ((ch)->misalign + (ch)->off)) #define CHAIN_PINNED(ch) (((ch)->flags & EVBUFFER_MEM_PINNED_ANY) != 0) #define CHAIN_PINNED_R(ch) (((ch)->flags & EVBUFFER_MEM_PINNED_R) != 0) /* evbuffer_ptr support */ #define PTR_NOT_FOUND(ptr) do { \ (ptr)->pos = -1; \ (ptr)->internal_.chain = NULL; \ (ptr)->internal_.pos_in_chain = 0; \ } while (0) static void evbuffer_chain_align(struct evbuffer_chain *chain); static int evbuffer_chain_should_realign(struct evbuffer_chain *chain, size_t datalen); static void evbuffer_deferred_callback(struct event_callback *cb, void *arg); static int evbuffer_ptr_memcmp(const struct evbuffer *buf, const struct evbuffer_ptr *pos, const char *mem, size_t len); static struct evbuffer_chain *evbuffer_expand_singlechain(struct evbuffer *buf, size_t datlen); static int evbuffer_ptr_subtract(struct evbuffer *buf, struct evbuffer_ptr *pos, size_t howfar); static int evbuffer_file_segment_materialize(struct evbuffer_file_segment *seg); static inline void evbuffer_chain_incref(struct evbuffer_chain *chain); static struct evbuffer_chain * evbuffer_chain_new(size_t size) { struct evbuffer_chain *chain; size_t to_alloc; if (size > EVBUFFER_CHAIN_MAX - EVBUFFER_CHAIN_SIZE) return (NULL); size += EVBUFFER_CHAIN_SIZE; /* get the next largest memory that can hold the buffer */ if (size < EVBUFFER_CHAIN_MAX / 2) { to_alloc = MIN_BUFFER_SIZE; while (to_alloc < size) { to_alloc <<= 1; } } else { to_alloc = size; } /* we get everything in one chunk */ if ((chain = mm_malloc(to_alloc)) == NULL) return (NULL); memset(chain, 0, EVBUFFER_CHAIN_SIZE); chain->buffer_len = to_alloc - EVBUFFER_CHAIN_SIZE; /* this way we can manipulate the buffer to different addresses, * which is required for mmap for example. */ chain->buffer = EVBUFFER_CHAIN_EXTRA(unsigned char, chain); chain->refcnt = 1; return (chain); } static inline void evbuffer_chain_free(struct evbuffer_chain *chain) { EVUTIL_ASSERT(chain->refcnt > 0); if (--chain->refcnt > 0) { /* chain is still referenced by other chains */ return; } if (CHAIN_PINNED(chain)) { /* will get freed once no longer dangling */ chain->refcnt++; chain->flags |= EVBUFFER_DANGLING; return; } /* safe to release chain, it's either a referencing * chain or all references to it have been freed */ if (chain->flags & EVBUFFER_REFERENCE) { struct evbuffer_chain_reference *info = EVBUFFER_CHAIN_EXTRA( struct evbuffer_chain_reference, chain); if (info->cleanupfn) (*info->cleanupfn)(chain->buffer, chain->buffer_len, info->extra); } if (chain->flags & EVBUFFER_FILESEGMENT) { struct evbuffer_chain_file_segment *info = EVBUFFER_CHAIN_EXTRA( struct evbuffer_chain_file_segment, chain); if (info->segment) { #ifdef _WIN32 if (info->segment->is_mapping) UnmapViewOfFile(chain->buffer); #endif evbuffer_file_segment_free(info->segment); } } if (chain->flags & EVBUFFER_MULTICAST) { struct evbuffer_multicast_parent *info = EVBUFFER_CHAIN_EXTRA( struct evbuffer_multicast_parent, chain); /* referencing chain is being freed, decrease * refcounts of source chain and associated * evbuffer (which get freed once both reach * zero) */ EVUTIL_ASSERT(info->source != NULL); EVUTIL_ASSERT(info->parent != NULL); EVBUFFER_LOCK(info->source); evbuffer_chain_free(info->parent); evbuffer_decref_and_unlock_(info->source); } mm_free(chain); } static void evbuffer_free_all_chains(struct evbuffer_chain *chain) { struct evbuffer_chain *next; for (; chain; chain = next) { next = chain->next; evbuffer_chain_free(chain); } } #ifndef NDEBUG static int evbuffer_chains_all_empty(struct evbuffer_chain *chain) { for (; chain; chain = chain->next) { if (chain->off) return 0; } return 1; } #else /* The definition is needed for EVUTIL_ASSERT, which uses sizeof to avoid "unused variable" warnings. */ static inline int evbuffer_chains_all_empty(struct evbuffer_chain *chain) { return 1; } #endif /* Free all trailing chains in 'buf' that are neither pinned nor empty, prior * to replacing them all with a new chain. Return a pointer to the place * where the new chain will go. * * Internal; requires lock. The caller must fix up buf->last and buf->first * as needed; they might have been freed. */ static struct evbuffer_chain ** evbuffer_free_trailing_empty_chains(struct evbuffer *buf) { struct evbuffer_chain **ch = buf->last_with_datap; /* Find the first victim chain. It might be *last_with_datap */ while ((*ch) && ((*ch)->off != 0 || CHAIN_PINNED(*ch))) ch = &(*ch)->next; if (*ch) { EVUTIL_ASSERT(evbuffer_chains_all_empty(*ch)); evbuffer_free_all_chains(*ch); *ch = NULL; } return ch; } /* Add a single chain 'chain' to the end of 'buf', freeing trailing empty * chains as necessary. Requires lock. Does not schedule callbacks. */ static void evbuffer_chain_insert(struct evbuffer *buf, struct evbuffer_chain *chain) { ASSERT_EVBUFFER_LOCKED(buf); if (*buf->last_with_datap == NULL) { /* There are no chains data on the buffer at all. */ EVUTIL_ASSERT(buf->last_with_datap == &buf->first); EVUTIL_ASSERT(buf->first == NULL); buf->first = buf->last = chain; } else { struct evbuffer_chain **chp; chp = evbuffer_free_trailing_empty_chains(buf); *chp = chain; if (chain->off) buf->last_with_datap = chp; buf->last = chain; } buf->total_len += chain->off; } static inline struct evbuffer_chain * evbuffer_chain_insert_new(struct evbuffer *buf, size_t datlen) { struct evbuffer_chain *chain; if ((chain = evbuffer_chain_new(datlen)) == NULL) return NULL; evbuffer_chain_insert(buf, chain); return chain; } void evbuffer_chain_pin_(struct evbuffer_chain *chain, unsigned flag) { EVUTIL_ASSERT((chain->flags & flag) == 0); chain->flags |= flag; } void evbuffer_chain_unpin_(struct evbuffer_chain *chain, unsigned flag) { EVUTIL_ASSERT((chain->flags & flag) != 0); chain->flags &= ~flag; if (chain->flags & EVBUFFER_DANGLING) evbuffer_chain_free(chain); } static inline void evbuffer_chain_incref(struct evbuffer_chain *chain) { ++chain->refcnt; } struct evbuffer * evbuffer_new(void) { struct evbuffer *buffer; buffer = mm_calloc(1, sizeof(struct evbuffer)); if (buffer == NULL) return (NULL); LIST_INIT(&buffer->callbacks); buffer->refcnt = 1; buffer->last_with_datap = &buffer->first; return (buffer); } int evbuffer_set_flags(struct evbuffer *buf, ev_uint64_t flags) { EVBUFFER_LOCK(buf); buf->flags |= (ev_uint32_t)flags; EVBUFFER_UNLOCK(buf); return 0; } int evbuffer_clear_flags(struct evbuffer *buf, ev_uint64_t flags) { EVBUFFER_LOCK(buf); buf->flags &= ~(ev_uint32_t)flags; EVBUFFER_UNLOCK(buf); return 0; } void evbuffer_incref_(struct evbuffer *buf) { EVBUFFER_LOCK(buf); ++buf->refcnt; EVBUFFER_UNLOCK(buf); } void evbuffer_incref_and_lock_(struct evbuffer *buf) { EVBUFFER_LOCK(buf); ++buf->refcnt; } int evbuffer_defer_callbacks(struct evbuffer *buffer, struct event_base *base) { EVBUFFER_LOCK(buffer); buffer->cb_queue = base; buffer->deferred_cbs = 1; event_deferred_cb_init_(&buffer->deferred, event_base_get_npriorities(base) / 2, evbuffer_deferred_callback, buffer); EVBUFFER_UNLOCK(buffer); return 0; } int evbuffer_enable_locking(struct evbuffer *buf, void *lock) { #ifdef EVENT__DISABLE_THREAD_SUPPORT return -1; #else if (buf->lock) return -1; if (!lock) { EVTHREAD_ALLOC_LOCK(lock, EVTHREAD_LOCKTYPE_RECURSIVE); if (!lock) return -1; buf->lock = lock; buf->own_lock = 1; } else { buf->lock = lock; buf->own_lock = 0; } return 0; #endif } void evbuffer_set_parent_(struct evbuffer *buf, struct bufferevent *bev) { EVBUFFER_LOCK(buf); buf->parent = bev; EVBUFFER_UNLOCK(buf); } static void evbuffer_run_callbacks(struct evbuffer *buffer, int running_deferred) { struct evbuffer_cb_entry *cbent, *next; struct evbuffer_cb_info info; size_t new_size; ev_uint32_t mask, masked_val; int clear = 1; if (running_deferred) { mask = EVBUFFER_CB_NODEFER|EVBUFFER_CB_ENABLED; masked_val = EVBUFFER_CB_ENABLED; } else if (buffer->deferred_cbs) { mask = EVBUFFER_CB_NODEFER|EVBUFFER_CB_ENABLED; masked_val = EVBUFFER_CB_NODEFER|EVBUFFER_CB_ENABLED; /* Don't zero-out n_add/n_del, since the deferred callbacks will want to see them. */ clear = 0; } else { mask = EVBUFFER_CB_ENABLED; masked_val = EVBUFFER_CB_ENABLED; } ASSERT_EVBUFFER_LOCKED(buffer); if (LIST_EMPTY(&buffer->callbacks)) { buffer->n_add_for_cb = buffer->n_del_for_cb = 0; return; } if (buffer->n_add_for_cb == 0 && buffer->n_del_for_cb == 0) return; new_size = buffer->total_len; info.orig_size = new_size + buffer->n_del_for_cb - buffer->n_add_for_cb; info.n_added = buffer->n_add_for_cb; info.n_deleted = buffer->n_del_for_cb; if (clear) { buffer->n_add_for_cb = 0; buffer->n_del_for_cb = 0; } for (cbent = LIST_FIRST(&buffer->callbacks); cbent != LIST_END(&buffer->callbacks); cbent = next) { /* Get the 'next' pointer now in case this callback decides * to remove itself or something. */ next = LIST_NEXT(cbent, next); if ((cbent->flags & mask) != masked_val) continue; if ((cbent->flags & EVBUFFER_CB_OBSOLETE)) cbent->cb.cb_obsolete(buffer, info.orig_size, new_size, cbent->cbarg); else cbent->cb.cb_func(buffer, &info, cbent->cbarg); } } void evbuffer_invoke_callbacks_(struct evbuffer *buffer) { if (LIST_EMPTY(&buffer->callbacks)) { buffer->n_add_for_cb = buffer->n_del_for_cb = 0; return; } if (buffer->deferred_cbs) { if (event_deferred_cb_schedule_(buffer->cb_queue, &buffer->deferred)) { evbuffer_incref_and_lock_(buffer); if (buffer->parent) bufferevent_incref_(buffer->parent); } EVBUFFER_UNLOCK(buffer); } evbuffer_run_callbacks(buffer, 0); } static void evbuffer_deferred_callback(struct event_callback *cb, void *arg) { struct bufferevent *parent = NULL; struct evbuffer *buffer = arg; /* XXXX It would be better to run these callbacks without holding the * lock */ EVBUFFER_LOCK(buffer); parent = buffer->parent; evbuffer_run_callbacks(buffer, 1); evbuffer_decref_and_unlock_(buffer); if (parent) bufferevent_decref_(parent); } static void evbuffer_remove_all_callbacks(struct evbuffer *buffer) { struct evbuffer_cb_entry *cbent; while ((cbent = LIST_FIRST(&buffer->callbacks))) { LIST_REMOVE(cbent, next); mm_free(cbent); } } void evbuffer_decref_and_unlock_(struct evbuffer *buffer) { struct evbuffer_chain *chain, *next; ASSERT_EVBUFFER_LOCKED(buffer); EVUTIL_ASSERT(buffer->refcnt > 0); if (--buffer->refcnt > 0) { EVBUFFER_UNLOCK(buffer); return; } for (chain = buffer->first; chain != NULL; chain = next) { next = chain->next; evbuffer_chain_free(chain); } evbuffer_remove_all_callbacks(buffer); if (buffer->deferred_cbs) event_deferred_cb_cancel_(buffer->cb_queue, &buffer->deferred); EVBUFFER_UNLOCK(buffer); if (buffer->own_lock) EVTHREAD_FREE_LOCK(buffer->lock, EVTHREAD_LOCKTYPE_RECURSIVE); mm_free(buffer); } void evbuffer_free(struct evbuffer *buffer) { EVBUFFER_LOCK(buffer); evbuffer_decref_and_unlock_(buffer); } void evbuffer_lock(struct evbuffer *buf) { EVBUFFER_LOCK(buf); } void evbuffer_unlock(struct evbuffer *buf) { EVBUFFER_UNLOCK(buf); } size_t evbuffer_get_length(const struct evbuffer *buffer) { size_t result; EVBUFFER_LOCK(buffer); result = (buffer->total_len); EVBUFFER_UNLOCK(buffer); return result; } size_t evbuffer_get_contiguous_space(const struct evbuffer *buf) { struct evbuffer_chain *chain; size_t result; EVBUFFER_LOCK(buf); chain = buf->first; result = (chain != NULL ? chain->off : 0); EVBUFFER_UNLOCK(buf); return result; } size_t evbuffer_add_iovec(struct evbuffer * buf, struct evbuffer_iovec * vec, int n_vec) { int n; size_t res; size_t to_alloc; EVBUFFER_LOCK(buf); res = to_alloc = 0; for (n = 0; n < n_vec; n++) { to_alloc += vec[n].iov_len; } if (evbuffer_expand_fast_(buf, to_alloc, 2) < 0) { goto done; } for (n = 0; n < n_vec; n++) { /* XXX each 'add' call here does a bunch of setup that's * obviated by evbuffer_expand_fast_, and some cleanup that we * would like to do only once. Instead we should just extract * the part of the code that's needed. */ if (evbuffer_add(buf, vec[n].iov_base, vec[n].iov_len) < 0) { goto done; } res += vec[n].iov_len; } done: EVBUFFER_UNLOCK(buf); return res; } int evbuffer_reserve_space(struct evbuffer *buf, ev_ssize_t size, struct evbuffer_iovec *vec, int n_vecs) { struct evbuffer_chain *chain, **chainp; int n = -1; EVBUFFER_LOCK(buf); if (buf->freeze_end) goto done; if (n_vecs < 1) goto done; if (n_vecs == 1) { if ((chain = evbuffer_expand_singlechain(buf, size)) == NULL) goto done; vec[0].iov_base = CHAIN_SPACE_PTR(chain); vec[0].iov_len = (size_t) CHAIN_SPACE_LEN(chain); EVUTIL_ASSERT(size<0 || (size_t)vec[0].iov_len >= (size_t)size); n = 1; } else { if (evbuffer_expand_fast_(buf, size, n_vecs)<0) goto done; n = evbuffer_read_setup_vecs_(buf, size, vec, n_vecs, &chainp, 0); } done: EVBUFFER_UNLOCK(buf); return n; } static int advance_last_with_data(struct evbuffer *buf) { int n = 0; ASSERT_EVBUFFER_LOCKED(buf); if (!*buf->last_with_datap) return 0; while ((*buf->last_with_datap)->next && (*buf->last_with_datap)->next->off) { buf->last_with_datap = &(*buf->last_with_datap)->next; ++n; } return n; } int evbuffer_commit_space(struct evbuffer *buf, struct evbuffer_iovec *vec, int n_vecs) { struct evbuffer_chain *chain, **firstchainp, **chainp; int result = -1; size_t added = 0; int i; EVBUFFER_LOCK(buf); if (buf->freeze_end) goto done; if (n_vecs == 0) { result = 0; goto done; } else if (n_vecs == 1 && (buf->last && vec[0].iov_base == (void*)CHAIN_SPACE_PTR(buf->last))) { /* The user only got or used one chain; it might not * be the first one with space in it. */ if ((size_t)vec[0].iov_len > (size_t)CHAIN_SPACE_LEN(buf->last)) goto done; buf->last->off += vec[0].iov_len; added = vec[0].iov_len; if (added) advance_last_with_data(buf); goto okay; } /* Advance 'firstchain' to the first chain with space in it. */ firstchainp = buf->last_with_datap; if (!*firstchainp) goto done; if (CHAIN_SPACE_LEN(*firstchainp) == 0) { firstchainp = &(*firstchainp)->next; } chain = *firstchainp; /* pass 1: make sure that the pointers and lengths of vecs[] are in * bounds before we try to commit anything. */ for (i=0; i CHAIN_SPACE_LEN(chain)) goto done; chain = chain->next; } /* pass 2: actually adjust all the chains. */ chainp = firstchainp; for (i=0; ioff += vec[i].iov_len; added += vec[i].iov_len; if (vec[i].iov_len) { buf->last_with_datap = chainp; } chainp = &(*chainp)->next; } okay: buf->total_len += added; buf->n_add_for_cb += added; result = 0; evbuffer_invoke_callbacks_(buf); done: EVBUFFER_UNLOCK(buf); return result; } static inline int HAS_PINNED_R(struct evbuffer *buf) { return (buf->last && CHAIN_PINNED_R(buf->last)); } static inline void ZERO_CHAIN(struct evbuffer *dst) { ASSERT_EVBUFFER_LOCKED(dst); dst->first = NULL; dst->last = NULL; dst->last_with_datap = &(dst)->first; dst->total_len = 0; } /* Prepares the contents of src to be moved to another buffer by removing * read-pinned chains. The first pinned chain is saved in first, and the * last in last. If src has no read-pinned chains, first and last are set * to NULL. */ static int PRESERVE_PINNED(struct evbuffer *src, struct evbuffer_chain **first, struct evbuffer_chain **last) { struct evbuffer_chain *chain, **pinned; ASSERT_EVBUFFER_LOCKED(src); if (!HAS_PINNED_R(src)) { *first = *last = NULL; return 0; } pinned = src->last_with_datap; if (!CHAIN_PINNED_R(*pinned)) pinned = &(*pinned)->next; EVUTIL_ASSERT(CHAIN_PINNED_R(*pinned)); chain = *first = *pinned; *last = src->last; /* If there's data in the first pinned chain, we need to allocate * a new chain and copy the data over. */ if (chain->off) { struct evbuffer_chain *tmp; EVUTIL_ASSERT(pinned == src->last_with_datap); tmp = evbuffer_chain_new(chain->off); if (!tmp) return -1; memcpy(tmp->buffer, chain->buffer + chain->misalign, chain->off); tmp->off = chain->off; *src->last_with_datap = tmp; src->last = tmp; chain->misalign += chain->off; chain->off = 0; } else { src->last = *src->last_with_datap; *pinned = NULL; } return 0; } static inline void RESTORE_PINNED(struct evbuffer *src, struct evbuffer_chain *pinned, struct evbuffer_chain *last) { ASSERT_EVBUFFER_LOCKED(src); if (!pinned) { ZERO_CHAIN(src); return; } src->first = pinned; src->last = last; src->last_with_datap = &src->first; src->total_len = 0; } static inline void COPY_CHAIN(struct evbuffer *dst, struct evbuffer *src) { ASSERT_EVBUFFER_LOCKED(dst); ASSERT_EVBUFFER_LOCKED(src); dst->first = src->first; if (src->last_with_datap == &src->first) dst->last_with_datap = &dst->first; else dst->last_with_datap = src->last_with_datap; dst->last = src->last; dst->total_len = src->total_len; } static void APPEND_CHAIN(struct evbuffer *dst, struct evbuffer *src) { struct evbuffer_chain **chp; ASSERT_EVBUFFER_LOCKED(dst); ASSERT_EVBUFFER_LOCKED(src); chp = evbuffer_free_trailing_empty_chains(dst); *chp = src->first; if (src->last_with_datap == &src->first) dst->last_with_datap = chp; else dst->last_with_datap = src->last_with_datap; dst->last = src->last; dst->total_len += src->total_len; } static inline void APPEND_CHAIN_MULTICAST(struct evbuffer *dst, struct evbuffer *src) { struct evbuffer_chain *tmp; struct evbuffer_chain *chain = src->first; struct evbuffer_multicast_parent *extra; ASSERT_EVBUFFER_LOCKED(dst); ASSERT_EVBUFFER_LOCKED(src); for (; chain; chain = chain->next) { if (!chain->off || chain->flags & EVBUFFER_DANGLING) { /* skip empty chains */ continue; } tmp = evbuffer_chain_new(sizeof(struct evbuffer_multicast_parent)); if (!tmp) { event_warn("%s: out of memory", __func__); return; } extra = EVBUFFER_CHAIN_EXTRA(struct evbuffer_multicast_parent, tmp); /* reference evbuffer containing source chain so it * doesn't get released while the chain is still * being referenced to */ evbuffer_incref_(src); extra->source = src; /* reference source chain which now becomes immutable */ evbuffer_chain_incref(chain); extra->parent = chain; chain->flags |= EVBUFFER_IMMUTABLE; tmp->buffer_len = chain->buffer_len; tmp->misalign = chain->misalign; tmp->off = chain->off; tmp->flags |= EVBUFFER_MULTICAST|EVBUFFER_IMMUTABLE; tmp->buffer = chain->buffer; evbuffer_chain_insert(dst, tmp); } } static void PREPEND_CHAIN(struct evbuffer *dst, struct evbuffer *src) { ASSERT_EVBUFFER_LOCKED(dst); ASSERT_EVBUFFER_LOCKED(src); src->last->next = dst->first; dst->first = src->first; dst->total_len += src->total_len; if (*dst->last_with_datap == NULL) { if (src->last_with_datap == &(src)->first) dst->last_with_datap = &dst->first; else dst->last_with_datap = src->last_with_datap; } else if (dst->last_with_datap == &dst->first) { dst->last_with_datap = &src->last->next; } } int evbuffer_add_buffer(struct evbuffer *outbuf, struct evbuffer *inbuf) { struct evbuffer_chain *pinned, *last; size_t in_total_len, out_total_len; int result = 0; EVBUFFER_LOCK2(inbuf, outbuf); in_total_len = inbuf->total_len; out_total_len = outbuf->total_len; if (in_total_len == 0 || outbuf == inbuf) goto done; if (outbuf->freeze_end || inbuf->freeze_start) { result = -1; goto done; } if (PRESERVE_PINNED(inbuf, &pinned, &last) < 0) { result = -1; goto done; } if (out_total_len == 0) { /* There might be an empty chain at the start of outbuf; free * it. */ evbuffer_free_all_chains(outbuf->first); COPY_CHAIN(outbuf, inbuf); } else { APPEND_CHAIN(outbuf, inbuf); } RESTORE_PINNED(inbuf, pinned, last); inbuf->n_del_for_cb += in_total_len; outbuf->n_add_for_cb += in_total_len; evbuffer_invoke_callbacks_(inbuf); evbuffer_invoke_callbacks_(outbuf); done: EVBUFFER_UNLOCK2(inbuf, outbuf); return result; } int evbuffer_add_buffer_reference(struct evbuffer *outbuf, struct evbuffer *inbuf) { size_t in_total_len, out_total_len; struct evbuffer_chain *chain; int result = 0; EVBUFFER_LOCK2(inbuf, outbuf); in_total_len = inbuf->total_len; out_total_len = outbuf->total_len; chain = inbuf->first; if (in_total_len == 0) goto done; if (outbuf->freeze_end || outbuf == inbuf) { result = -1; goto done; } for (; chain; chain = chain->next) { if ((chain->flags & (EVBUFFER_FILESEGMENT|EVBUFFER_SENDFILE|EVBUFFER_MULTICAST)) != 0) { /* chain type can not be referenced */ result = -1; goto done; } } if (out_total_len == 0) { /* There might be an empty chain at the start of outbuf; free * it. */ evbuffer_free_all_chains(outbuf->first); } APPEND_CHAIN_MULTICAST(outbuf, inbuf); outbuf->n_add_for_cb += in_total_len; evbuffer_invoke_callbacks_(outbuf); done: EVBUFFER_UNLOCK2(inbuf, outbuf); return result; } int evbuffer_prepend_buffer(struct evbuffer *outbuf, struct evbuffer *inbuf) { struct evbuffer_chain *pinned, *last; size_t in_total_len, out_total_len; int result = 0; EVBUFFER_LOCK2(inbuf, outbuf); in_total_len = inbuf->total_len; out_total_len = outbuf->total_len; if (!in_total_len || inbuf == outbuf) goto done; if (outbuf->freeze_start || inbuf->freeze_start) { result = -1; goto done; } if (PRESERVE_PINNED(inbuf, &pinned, &last) < 0) { result = -1; goto done; } if (out_total_len == 0) { /* There might be an empty chain at the start of outbuf; free * it. */ evbuffer_free_all_chains(outbuf->first); COPY_CHAIN(outbuf, inbuf); } else { PREPEND_CHAIN(outbuf, inbuf); } RESTORE_PINNED(inbuf, pinned, last); inbuf->n_del_for_cb += in_total_len; outbuf->n_add_for_cb += in_total_len; evbuffer_invoke_callbacks_(inbuf); evbuffer_invoke_callbacks_(outbuf); done: EVBUFFER_UNLOCK2(inbuf, outbuf); return result; } int evbuffer_drain(struct evbuffer *buf, size_t len) { struct evbuffer_chain *chain, *next; size_t remaining, old_len; int result = 0; EVBUFFER_LOCK(buf); old_len = buf->total_len; if (old_len == 0) goto done; if (buf->freeze_start) { result = -1; goto done; } if (len >= old_len && !HAS_PINNED_R(buf)) { len = old_len; for (chain = buf->first; chain != NULL; chain = next) { next = chain->next; evbuffer_chain_free(chain); } ZERO_CHAIN(buf); } else { if (len >= old_len) len = old_len; buf->total_len -= len; remaining = len; for (chain = buf->first; remaining >= chain->off; chain = next) { next = chain->next; remaining -= chain->off; if (chain == *buf->last_with_datap) { buf->last_with_datap = &buf->first; } if (&chain->next == buf->last_with_datap) buf->last_with_datap = &buf->first; if (CHAIN_PINNED_R(chain)) { EVUTIL_ASSERT(remaining == 0); chain->misalign += chain->off; chain->off = 0; break; } else evbuffer_chain_free(chain); } buf->first = chain; EVUTIL_ASSERT(chain && remaining <= chain->off); chain->misalign += remaining; chain->off -= remaining; } buf->n_del_for_cb += len; /* Tell someone about changes in this buffer */ evbuffer_invoke_callbacks_(buf); done: EVBUFFER_UNLOCK(buf); return result; } /* Reads data from an event buffer and drains the bytes read */ int evbuffer_remove(struct evbuffer *buf, void *data_out, size_t datlen) { ev_ssize_t n; EVBUFFER_LOCK(buf); n = evbuffer_copyout_from(buf, NULL, data_out, datlen); if (n > 0) { if (evbuffer_drain(buf, n)<0) n = -1; } EVBUFFER_UNLOCK(buf); return (int)n; } ev_ssize_t evbuffer_copyout(struct evbuffer *buf, void *data_out, size_t datlen) { return evbuffer_copyout_from(buf, NULL, data_out, datlen); } ev_ssize_t evbuffer_copyout_from(struct evbuffer *buf, const struct evbuffer_ptr *pos, void *data_out, size_t datlen) { /*XXX fails badly on sendfile case. */ struct evbuffer_chain *chain; char *data = data_out; size_t nread; ev_ssize_t result = 0; size_t pos_in_chain; EVBUFFER_LOCK(buf); if (pos) { if (datlen > (size_t)(EV_SSIZE_MAX - pos->pos)) { result = -1; goto done; } chain = pos->internal_.chain; pos_in_chain = pos->internal_.pos_in_chain; if (datlen + pos->pos > buf->total_len) datlen = buf->total_len - pos->pos; } else { chain = buf->first; pos_in_chain = 0; if (datlen > buf->total_len) datlen = buf->total_len; } if (datlen == 0) goto done; if (buf->freeze_start) { result = -1; goto done; } nread = datlen; while (datlen && datlen >= chain->off - pos_in_chain) { size_t copylen = chain->off - pos_in_chain; memcpy(data, chain->buffer + chain->misalign + pos_in_chain, copylen); data += copylen; datlen -= copylen; chain = chain->next; pos_in_chain = 0; EVUTIL_ASSERT(chain || datlen==0); } if (datlen) { EVUTIL_ASSERT(chain); EVUTIL_ASSERT(datlen+pos_in_chain <= chain->off); memcpy(data, chain->buffer + chain->misalign + pos_in_chain, datlen); } result = nread; done: EVBUFFER_UNLOCK(buf); return result; } /* reads data from the src buffer to the dst buffer, avoids memcpy as * possible. */ /* XXXX should return ev_ssize_t */ int evbuffer_remove_buffer(struct evbuffer *src, struct evbuffer *dst, size_t datlen) { /*XXX We should have an option to force this to be zero-copy.*/ /*XXX can fail badly on sendfile case. */ struct evbuffer_chain *chain, *previous; size_t nread = 0; int result; EVBUFFER_LOCK2(src, dst); chain = previous = src->first; if (datlen == 0 || dst == src) { result = 0; goto done; } if (dst->freeze_end || src->freeze_start) { result = -1; goto done; } /* short-cut if there is no more data buffered */ if (datlen >= src->total_len) { datlen = src->total_len; evbuffer_add_buffer(dst, src); result = (int)datlen; /*XXXX should return ev_ssize_t*/ goto done; } /* removes chains if possible */ while (chain->off <= datlen) { /* We can't remove the last with data from src unless we * remove all chains, in which case we would have done the if * block above */ EVUTIL_ASSERT(chain != *src->last_with_datap); nread += chain->off; datlen -= chain->off; previous = chain; if (src->last_with_datap == &chain->next) src->last_with_datap = &src->first; chain = chain->next; } if (nread) { /* we can remove the chain */ struct evbuffer_chain **chp; chp = evbuffer_free_trailing_empty_chains(dst); if (dst->first == NULL) { dst->first = src->first; } else { *chp = src->first; } dst->last = previous; previous->next = NULL; src->first = chain; advance_last_with_data(dst); dst->total_len += nread; dst->n_add_for_cb += nread; } /* we know that there is more data in the src buffer than * we want to read, so we manually drain the chain */ evbuffer_add(dst, chain->buffer + chain->misalign, datlen); chain->misalign += datlen; chain->off -= datlen; nread += datlen; /* You might think we would want to increment dst->n_add_for_cb * here too. But evbuffer_add above already took care of that. */ src->total_len -= nread; src->n_del_for_cb += nread; if (nread) { evbuffer_invoke_callbacks_(dst); evbuffer_invoke_callbacks_(src); } result = (int)nread;/*XXXX should change return type */ done: EVBUFFER_UNLOCK2(src, dst); return result; } unsigned char * evbuffer_pullup(struct evbuffer *buf, ev_ssize_t size) { struct evbuffer_chain *chain, *next, *tmp, *last_with_data; unsigned char *buffer, *result = NULL; ev_ssize_t remaining; int removed_last_with_data = 0; int removed_last_with_datap = 0; EVBUFFER_LOCK(buf); chain = buf->first; if (size < 0) size = buf->total_len; /* if size > buf->total_len, we cannot guarantee to the user that she * is going to have a long enough buffer afterwards; so we return * NULL */ if (size == 0 || (size_t)size > buf->total_len) goto done; /* No need to pull up anything; the first size bytes are * already here. */ if (chain->off >= (size_t)size) { result = chain->buffer + chain->misalign; goto done; } /* Make sure that none of the chains we need to copy from is pinned. */ remaining = size - chain->off; EVUTIL_ASSERT(remaining >= 0); for (tmp=chain->next; tmp; tmp=tmp->next) { if (CHAIN_PINNED(tmp)) goto done; if (tmp->off >= (size_t)remaining) break; remaining -= tmp->off; } if (CHAIN_PINNED(chain)) { size_t old_off = chain->off; if (CHAIN_SPACE_LEN(chain) < size - chain->off) { /* not enough room at end of chunk. */ goto done; } buffer = CHAIN_SPACE_PTR(chain); tmp = chain; tmp->off = size; size -= old_off; chain = chain->next; } else if (chain->buffer_len - chain->misalign >= (size_t)size) { /* already have enough space in the first chain */ size_t old_off = chain->off; buffer = chain->buffer + chain->misalign + chain->off; tmp = chain; tmp->off = size; size -= old_off; chain = chain->next; } else { if ((tmp = evbuffer_chain_new(size)) == NULL) { event_warn("%s: out of memory", __func__); goto done; } buffer = tmp->buffer; tmp->off = size; buf->first = tmp; } /* TODO(niels): deal with buffers that point to NULL like sendfile */ /* Copy and free every chunk that will be entirely pulled into tmp */ last_with_data = *buf->last_with_datap; for (; chain != NULL && (size_t)size >= chain->off; chain = next) { next = chain->next; memcpy(buffer, chain->buffer + chain->misalign, chain->off); size -= chain->off; buffer += chain->off; if (chain == last_with_data) removed_last_with_data = 1; if (&chain->next == buf->last_with_datap) removed_last_with_datap = 1; evbuffer_chain_free(chain); } if (chain != NULL) { memcpy(buffer, chain->buffer + chain->misalign, size); chain->misalign += size; chain->off -= size; } else { buf->last = tmp; } tmp->next = chain; if (removed_last_with_data) { buf->last_with_datap = &buf->first; } else if (removed_last_with_datap) { if (buf->first->next && buf->first->next->off) buf->last_with_datap = &buf->first->next; else buf->last_with_datap = &buf->first; } result = (tmp->buffer + tmp->misalign); done: EVBUFFER_UNLOCK(buf); return result; } /* * Reads a line terminated by either '\r\n', '\n\r' or '\r' or '\n'. * The returned buffer needs to be freed by the called. */ char * evbuffer_readline(struct evbuffer *buffer) { return evbuffer_readln(buffer, NULL, EVBUFFER_EOL_ANY); } static inline ev_ssize_t evbuffer_strchr(struct evbuffer_ptr *it, const char chr) { struct evbuffer_chain *chain = it->internal_.chain; size_t i = it->internal_.pos_in_chain; while (chain != NULL) { char *buffer = (char *)chain->buffer + chain->misalign; char *cp = memchr(buffer+i, chr, chain->off-i); if (cp) { it->internal_.chain = chain; it->internal_.pos_in_chain = cp - buffer; it->pos += (cp - buffer - i); return it->pos; } it->pos += chain->off - i; i = 0; chain = chain->next; } return (-1); } static inline char * find_eol_char(char *s, size_t len) { #define CHUNK_SZ 128 /* Lots of benchmarking found this approach to be faster in practice * than doing two memchrs over the whole buffer, doin a memchr on each * char of the buffer, or trying to emulate memchr by hand. */ char *s_end, *cr, *lf; s_end = s+len; while (s < s_end) { size_t chunk = (s + CHUNK_SZ < s_end) ? CHUNK_SZ : (s_end - s); cr = memchr(s, '\r', chunk); lf = memchr(s, '\n', chunk); if (cr) { if (lf && lf < cr) return lf; return cr; } else if (lf) { return lf; } s += CHUNK_SZ; } return NULL; #undef CHUNK_SZ } static ev_ssize_t evbuffer_find_eol_char(struct evbuffer_ptr *it) { struct evbuffer_chain *chain = it->internal_.chain; size_t i = it->internal_.pos_in_chain; while (chain != NULL) { char *buffer = (char *)chain->buffer + chain->misalign; char *cp = find_eol_char(buffer+i, chain->off-i); if (cp) { it->internal_.chain = chain; it->internal_.pos_in_chain = cp - buffer; it->pos += (cp - buffer) - i; return it->pos; } it->pos += chain->off - i; i = 0; chain = chain->next; } return (-1); } static inline int evbuffer_strspn( struct evbuffer_ptr *ptr, const char *chrset) { int count = 0; struct evbuffer_chain *chain = ptr->internal_.chain; size_t i = ptr->internal_.pos_in_chain; if (!chain) return 0; while (1) { char *buffer = (char *)chain->buffer + chain->misalign; for (; i < chain->off; ++i) { const char *p = chrset; while (*p) { if (buffer[i] == *p++) goto next; } ptr->internal_.chain = chain; ptr->internal_.pos_in_chain = i; ptr->pos += count; return count; next: ++count; } i = 0; if (! chain->next) { ptr->internal_.chain = chain; ptr->internal_.pos_in_chain = i; ptr->pos += count; return count; } chain = chain->next; } } static inline int evbuffer_getchr(struct evbuffer_ptr *it) { struct evbuffer_chain *chain = it->internal_.chain; size_t off = it->internal_.pos_in_chain; if (chain == NULL) return -1; return (unsigned char)chain->buffer[chain->misalign + off]; } struct evbuffer_ptr evbuffer_search_eol(struct evbuffer *buffer, struct evbuffer_ptr *start, size_t *eol_len_out, enum evbuffer_eol_style eol_style) { struct evbuffer_ptr it, it2; size_t extra_drain = 0; int ok = 0; /* Avoid locking in trivial edge cases */ if (start && start->internal_.chain == NULL) { PTR_NOT_FOUND(&it); if (eol_len_out) *eol_len_out = extra_drain; return it; } EVBUFFER_LOCK(buffer); if (start) { memcpy(&it, start, sizeof(it)); } else { it.pos = 0; it.internal_.chain = buffer->first; it.internal_.pos_in_chain = 0; } /* the eol_style determines our first stop character and how many * characters we are going to drain afterwards. */ switch (eol_style) { case EVBUFFER_EOL_ANY: if (evbuffer_find_eol_char(&it) < 0) goto done; memcpy(&it2, &it, sizeof(it)); extra_drain = evbuffer_strspn(&it2, "\r\n"); break; case EVBUFFER_EOL_CRLF_STRICT: { it = evbuffer_search(buffer, "\r\n", 2, &it); if (it.pos < 0) goto done; extra_drain = 2; break; } case EVBUFFER_EOL_CRLF: { ev_ssize_t start_pos = it.pos; /* Look for a LF ... */ if (evbuffer_strchr(&it, '\n') < 0) goto done; extra_drain = 1; /* ... optionally preceeded by a CR. */ if (it.pos == start_pos) break; /* If the first character is \n, don't back up */ /* This potentially does an extra linear walk over the first * few chains. Probably, that's not too expensive unless you * have a really pathological setup. */ memcpy(&it2, &it, sizeof(it)); if (evbuffer_ptr_subtract(buffer, &it2, 1)<0) break; if (evbuffer_getchr(&it2) == '\r') { memcpy(&it, &it2, sizeof(it)); extra_drain = 2; } break; } case EVBUFFER_EOL_LF: if (evbuffer_strchr(&it, '\n') < 0) goto done; extra_drain = 1; break; case EVBUFFER_EOL_NUL: if (evbuffer_strchr(&it, '\0') < 0) goto done; extra_drain = 1; break; default: goto done; } ok = 1; done: EVBUFFER_UNLOCK(buffer); if (!ok) PTR_NOT_FOUND(&it); if (eol_len_out) *eol_len_out = extra_drain; return it; } char * evbuffer_readln(struct evbuffer *buffer, size_t *n_read_out, enum evbuffer_eol_style eol_style) { struct evbuffer_ptr it; char *line; size_t n_to_copy=0, extra_drain=0; char *result = NULL; EVBUFFER_LOCK(buffer); if (buffer->freeze_start) { goto done; } it = evbuffer_search_eol(buffer, NULL, &extra_drain, eol_style); if (it.pos < 0) goto done; n_to_copy = it.pos; if ((line = mm_malloc(n_to_copy+1)) == NULL) { event_warn("%s: out of memory", __func__); goto done; } evbuffer_remove(buffer, line, n_to_copy); line[n_to_copy] = '\0'; evbuffer_drain(buffer, extra_drain); result = line; done: EVBUFFER_UNLOCK(buffer); if (n_read_out) *n_read_out = result ? n_to_copy : 0; return result; } #define EVBUFFER_CHAIN_MAX_AUTO_SIZE 4096 /* Adds data to an event buffer */ int evbuffer_add(struct evbuffer *buf, const void *data_in, size_t datlen) { struct evbuffer_chain *chain, *tmp; const unsigned char *data = data_in; size_t remain, to_alloc; int result = -1; EVBUFFER_LOCK(buf); if (buf->freeze_end) { goto done; } /* Prevent buf->total_len overflow */ if (datlen > EV_SIZE_MAX - buf->total_len) { goto done; } if (*buf->last_with_datap == NULL) { chain = buf->last; } else { chain = *buf->last_with_datap; } /* If there are no chains allocated for this buffer, allocate one * big enough to hold all the data. */ if (chain == NULL) { chain = evbuffer_chain_new(datlen); if (!chain) goto done; evbuffer_chain_insert(buf, chain); } if ((chain->flags & EVBUFFER_IMMUTABLE) == 0) { /* Always true for mutable buffers */ EVUTIL_ASSERT(chain->misalign >= 0 && (ev_uint64_t)chain->misalign <= EVBUFFER_CHAIN_MAX); remain = chain->buffer_len - (size_t)chain->misalign - chain->off; if (remain >= datlen) { /* there's enough space to hold all the data in the * current last chain */ memcpy(chain->buffer + chain->misalign + chain->off, data, datlen); chain->off += datlen; buf->total_len += datlen; buf->n_add_for_cb += datlen; goto out; } else if (!CHAIN_PINNED(chain) && evbuffer_chain_should_realign(chain, datlen)) { /* we can fit the data into the misalignment */ evbuffer_chain_align(chain); memcpy(chain->buffer + chain->off, data, datlen); chain->off += datlen; buf->total_len += datlen; buf->n_add_for_cb += datlen; goto out; } } else { /* we cannot write any data to the last chain */ remain = 0; } /* we need to add another chain */ to_alloc = chain->buffer_len; if (to_alloc <= EVBUFFER_CHAIN_MAX_AUTO_SIZE/2) to_alloc <<= 1; if (datlen > to_alloc) to_alloc = datlen; tmp = evbuffer_chain_new(to_alloc); if (tmp == NULL) goto done; if (remain) { memcpy(chain->buffer + chain->misalign + chain->off, data, remain); chain->off += remain; buf->total_len += remain; buf->n_add_for_cb += remain; } data += remain; datlen -= remain; memcpy(tmp->buffer, data, datlen); tmp->off = datlen; evbuffer_chain_insert(buf, tmp); buf->n_add_for_cb += datlen; out: evbuffer_invoke_callbacks_(buf); result = 0; done: EVBUFFER_UNLOCK(buf); return result; } int evbuffer_prepend(struct evbuffer *buf, const void *data, size_t datlen) { struct evbuffer_chain *chain, *tmp; int result = -1; EVBUFFER_LOCK(buf); if (buf->freeze_start) { goto done; } if (datlen > EV_SIZE_MAX - buf->total_len) { goto done; } chain = buf->first; if (chain == NULL) { chain = evbuffer_chain_new(datlen); if (!chain) goto done; evbuffer_chain_insert(buf, chain); } /* we cannot touch immutable buffers */ if ((chain->flags & EVBUFFER_IMMUTABLE) == 0) { /* Always true for mutable buffers */ EVUTIL_ASSERT(chain->misalign >= 0 && (ev_uint64_t)chain->misalign <= EVBUFFER_CHAIN_MAX); /* If this chain is empty, we can treat it as * 'empty at the beginning' rather than 'empty at the end' */ if (chain->off == 0) chain->misalign = chain->buffer_len; if ((size_t)chain->misalign >= datlen) { /* we have enough space to fit everything */ memcpy(chain->buffer + chain->misalign - datlen, data, datlen); chain->off += datlen; chain->misalign -= datlen; buf->total_len += datlen; buf->n_add_for_cb += datlen; goto out; } else if (chain->misalign) { /* we can only fit some of the data. */ memcpy(chain->buffer, (char*)data + datlen - chain->misalign, (size_t)chain->misalign); chain->off += (size_t)chain->misalign; buf->total_len += (size_t)chain->misalign; buf->n_add_for_cb += (size_t)chain->misalign; datlen -= (size_t)chain->misalign; chain->misalign = 0; } } /* we need to add another chain */ if ((tmp = evbuffer_chain_new(datlen)) == NULL) goto done; buf->first = tmp; if (buf->last_with_datap == &buf->first) buf->last_with_datap = &tmp->next; tmp->next = chain; tmp->off = datlen; EVUTIL_ASSERT(datlen <= tmp->buffer_len); tmp->misalign = tmp->buffer_len - datlen; memcpy(tmp->buffer + tmp->misalign, data, datlen); buf->total_len += datlen; buf->n_add_for_cb += datlen; out: evbuffer_invoke_callbacks_(buf); result = 0; done: EVBUFFER_UNLOCK(buf); return result; } /** Helper: realigns the memory in chain->buffer so that misalign is 0. */ static void evbuffer_chain_align(struct evbuffer_chain *chain) { EVUTIL_ASSERT(!(chain->flags & EVBUFFER_IMMUTABLE)); EVUTIL_ASSERT(!(chain->flags & EVBUFFER_MEM_PINNED_ANY)); memmove(chain->buffer, chain->buffer + chain->misalign, chain->off); chain->misalign = 0; } #define MAX_TO_COPY_IN_EXPAND 4096 #define MAX_TO_REALIGN_IN_EXPAND 2048 /** Helper: return true iff we should realign chain to fit datalen bytes of data in it. */ static int evbuffer_chain_should_realign(struct evbuffer_chain *chain, size_t datlen) { return chain->buffer_len - chain->off >= datlen && (chain->off < chain->buffer_len / 2) && (chain->off <= MAX_TO_REALIGN_IN_EXPAND); } /* Expands the available space in the event buffer to at least datlen, all in * a single chunk. Return that chunk. */ static struct evbuffer_chain * evbuffer_expand_singlechain(struct evbuffer *buf, size_t datlen) { struct evbuffer_chain *chain, **chainp; struct evbuffer_chain *result = NULL; ASSERT_EVBUFFER_LOCKED(buf); chainp = buf->last_with_datap; /* XXX If *chainp is no longer writeable, but has enough space in its * misalign, this might be a bad idea: we could still use *chainp, not * (*chainp)->next. */ if (*chainp && CHAIN_SPACE_LEN(*chainp) == 0) chainp = &(*chainp)->next; /* 'chain' now points to the first chain with writable space (if any) * We will either use it, realign it, replace it, or resize it. */ chain = *chainp; if (chain == NULL || (chain->flags & (EVBUFFER_IMMUTABLE|EVBUFFER_MEM_PINNED_ANY))) { /* We can't use the last_with_data chain at all. Just add a * new one that's big enough. */ goto insert_new; } /* If we can fit all the data, then we don't have to do anything */ if (CHAIN_SPACE_LEN(chain) >= datlen) { result = chain; goto ok; } /* If the chain is completely empty, just replace it by adding a new * empty chain. */ if (chain->off == 0) { goto insert_new; } /* If the misalignment plus the remaining space fulfills our data * needs, we could just force an alignment to happen. Afterwards, we * have enough space. But only do this if we're saving a lot of space * and not moving too much data. Otherwise the space savings are * probably offset by the time lost in copying. */ if (evbuffer_chain_should_realign(chain, datlen)) { evbuffer_chain_align(chain); result = chain; goto ok; } /* At this point, we can either resize the last chunk with space in * it, use the next chunk after it, or If we add a new chunk, we waste * CHAIN_SPACE_LEN(chain) bytes in the former last chunk. If we * resize, we have to copy chain->off bytes. */ /* Would expanding this chunk be affordable and worthwhile? */ if (CHAIN_SPACE_LEN(chain) < chain->buffer_len / 8 || chain->off > MAX_TO_COPY_IN_EXPAND || datlen >= (EVBUFFER_CHAIN_MAX - chain->off)) { /* It's not worth resizing this chain. Can the next one be * used? */ if (chain->next && CHAIN_SPACE_LEN(chain->next) >= datlen) { /* Yes, we can just use the next chain (which should * be empty. */ result = chain->next; goto ok; } else { /* No; append a new chain (which will free all * terminal empty chains.) */ goto insert_new; } } else { /* Okay, we're going to try to resize this chain: Not doing so * would waste at least 1/8 of its current allocation, and we * can do so without having to copy more than * MAX_TO_COPY_IN_EXPAND bytes. */ /* figure out how much space we need */ size_t length = chain->off + datlen; struct evbuffer_chain *tmp = evbuffer_chain_new(length); if (tmp == NULL) goto err; /* copy the data over that we had so far */ tmp->off = chain->off; memcpy(tmp->buffer, chain->buffer + chain->misalign, chain->off); /* fix up the list */ EVUTIL_ASSERT(*chainp == chain); result = *chainp = tmp; if (buf->last == chain) buf->last = tmp; tmp->next = chain->next; evbuffer_chain_free(chain); goto ok; } insert_new: result = evbuffer_chain_insert_new(buf, datlen); if (!result) goto err; ok: EVUTIL_ASSERT(result); EVUTIL_ASSERT(CHAIN_SPACE_LEN(result) >= datlen); err: return result; } /* Make sure that datlen bytes are available for writing in the last n * chains. Never copies or moves data. */ int evbuffer_expand_fast_(struct evbuffer *buf, size_t datlen, int n) { struct evbuffer_chain *chain = buf->last, *tmp, *next; size_t avail; int used; ASSERT_EVBUFFER_LOCKED(buf); EVUTIL_ASSERT(n >= 2); if (chain == NULL || (chain->flags & EVBUFFER_IMMUTABLE)) { /* There is no last chunk, or we can't touch the last chunk. * Just add a new chunk. */ chain = evbuffer_chain_new(datlen); if (chain == NULL) return (-1); evbuffer_chain_insert(buf, chain); return (0); } used = 0; /* number of chains we're using space in. */ avail = 0; /* how much space they have. */ /* How many bytes can we stick at the end of buffer as it is? Iterate * over the chains at the end of the buffer, tring to see how much * space we have in the first n. */ for (chain = *buf->last_with_datap; chain; chain = chain->next) { if (chain->off) { size_t space = (size_t) CHAIN_SPACE_LEN(chain); EVUTIL_ASSERT(chain == *buf->last_with_datap); if (space) { avail += space; ++used; } } else { /* No data in chain; realign it. */ chain->misalign = 0; avail += chain->buffer_len; ++used; } if (avail >= datlen) { /* There is already enough space. Just return */ return (0); } if (used == n) break; } /* There wasn't enough space in the first n chains with space in * them. Either add a new chain with enough space, or replace all * empty chains with one that has enough space, depending on n. */ if (used < n) { /* The loop ran off the end of the chains before it hit n * chains; we can add another. */ EVUTIL_ASSERT(chain == NULL); tmp = evbuffer_chain_new(datlen - avail); if (tmp == NULL) return (-1); buf->last->next = tmp; buf->last = tmp; /* (we would only set last_with_data if we added the first * chain. But if the buffer had no chains, we would have * just allocated a new chain earlier) */ return (0); } else { /* Nuke _all_ the empty chains. */ int rmv_all = 0; /* True iff we removed last_with_data. */ chain = *buf->last_with_datap; if (!chain->off) { EVUTIL_ASSERT(chain == buf->first); rmv_all = 1; avail = 0; } else { /* can't overflow, since only mutable chains have * huge misaligns. */ avail = (size_t) CHAIN_SPACE_LEN(chain); chain = chain->next; } for (; chain; chain = next) { next = chain->next; EVUTIL_ASSERT(chain->off == 0); evbuffer_chain_free(chain); } EVUTIL_ASSERT(datlen >= avail); tmp = evbuffer_chain_new(datlen - avail); if (tmp == NULL) { if (rmv_all) { ZERO_CHAIN(buf); } else { buf->last = *buf->last_with_datap; (*buf->last_with_datap)->next = NULL; } return (-1); } if (rmv_all) { buf->first = buf->last = tmp; buf->last_with_datap = &buf->first; } else { (*buf->last_with_datap)->next = tmp; buf->last = tmp; } return (0); } } int evbuffer_expand(struct evbuffer *buf, size_t datlen) { struct evbuffer_chain *chain; EVBUFFER_LOCK(buf); chain = evbuffer_expand_singlechain(buf, datlen); EVBUFFER_UNLOCK(buf); return chain ? 0 : -1; } /* * Reads data from a file descriptor into a buffer. */ #if defined(EVENT__HAVE_SYS_UIO_H) || defined(_WIN32) #define USE_IOVEC_IMPL #endif #ifdef USE_IOVEC_IMPL #ifdef EVENT__HAVE_SYS_UIO_H /* number of iovec we use for writev, fragmentation is going to determine * how much we end up writing */ #define DEFAULT_WRITE_IOVEC 128 #if defined(UIO_MAXIOV) && UIO_MAXIOV < DEFAULT_WRITE_IOVEC #define NUM_WRITE_IOVEC UIO_MAXIOV #elif defined(IOV_MAX) && IOV_MAX < DEFAULT_WRITE_IOVEC #define NUM_WRITE_IOVEC IOV_MAX #else #define NUM_WRITE_IOVEC DEFAULT_WRITE_IOVEC #endif #define IOV_TYPE struct iovec #define IOV_PTR_FIELD iov_base #define IOV_LEN_FIELD iov_len #define IOV_LEN_TYPE size_t #else #define NUM_WRITE_IOVEC 16 #define IOV_TYPE WSABUF #define IOV_PTR_FIELD buf #define IOV_LEN_FIELD len #define IOV_LEN_TYPE unsigned long #endif #endif #define NUM_READ_IOVEC 4 #define EVBUFFER_MAX_READ 4096 /** Helper function to figure out which space to use for reading data into an evbuffer. Internal use only. @param buf The buffer to read into @param howmuch How much we want to read. @param vecs An array of two or more iovecs or WSABUFs. @param n_vecs_avail The length of vecs @param chainp A pointer to a variable to hold the first chain we're reading into. @param exact Boolean: if true, we do not provide more than 'howmuch' space in the vectors, even if more space is available. @return The number of buffers we're using. */ int evbuffer_read_setup_vecs_(struct evbuffer *buf, ev_ssize_t howmuch, struct evbuffer_iovec *vecs, int n_vecs_avail, struct evbuffer_chain ***chainp, int exact) { struct evbuffer_chain *chain; struct evbuffer_chain **firstchainp; size_t so_far; int i; ASSERT_EVBUFFER_LOCKED(buf); if (howmuch < 0) return -1; so_far = 0; /* Let firstchain be the first chain with any space on it */ firstchainp = buf->last_with_datap; if (CHAIN_SPACE_LEN(*firstchainp) == 0) { firstchainp = &(*firstchainp)->next; } chain = *firstchainp; for (i = 0; i < n_vecs_avail && so_far < (size_t)howmuch; ++i) { size_t avail = (size_t) CHAIN_SPACE_LEN(chain); if (avail > (howmuch - so_far) && exact) avail = howmuch - so_far; vecs[i].iov_base = CHAIN_SPACE_PTR(chain); vecs[i].iov_len = avail; so_far += avail; chain = chain->next; } *chainp = firstchainp; return i; } static int get_n_bytes_readable_on_socket(evutil_socket_t fd) { #if defined(FIONREAD) && defined(_WIN32) unsigned long lng = EVBUFFER_MAX_READ; if (ioctlsocket(fd, FIONREAD, &lng) < 0) return -1; /* Can overflow, but mostly harmlessly. XXXX */ return (int)lng; #elif defined(FIONREAD) int n = EVBUFFER_MAX_READ; if (ioctl(fd, FIONREAD, &n) < 0) return -1; return n; #else return EVBUFFER_MAX_READ; #endif } /* TODO(niels): should this function return ev_ssize_t and take ev_ssize_t * as howmuch? */ int evbuffer_read(struct evbuffer *buf, evutil_socket_t fd, int howmuch) { struct evbuffer_chain **chainp; int n; int result; #ifdef USE_IOVEC_IMPL int nvecs, i, remaining; #else struct evbuffer_chain *chain; unsigned char *p; #endif EVBUFFER_LOCK(buf); if (buf->freeze_end) { result = -1; goto done; } n = get_n_bytes_readable_on_socket(fd); if (n <= 0 || n > EVBUFFER_MAX_READ) n = EVBUFFER_MAX_READ; if (howmuch < 0 || howmuch > n) howmuch = n; #ifdef USE_IOVEC_IMPL /* Since we can use iovecs, we're willing to use the last * NUM_READ_IOVEC chains. */ if (evbuffer_expand_fast_(buf, howmuch, NUM_READ_IOVEC) == -1) { result = -1; goto done; } else { IOV_TYPE vecs[NUM_READ_IOVEC]; #ifdef EVBUFFER_IOVEC_IS_NATIVE_ nvecs = evbuffer_read_setup_vecs_(buf, howmuch, vecs, NUM_READ_IOVEC, &chainp, 1); #else /* We aren't using the native struct iovec. Therefore, we are on win32. */ struct evbuffer_iovec ev_vecs[NUM_READ_IOVEC]; nvecs = evbuffer_read_setup_vecs_(buf, howmuch, ev_vecs, 2, &chainp, 1); for (i=0; i < nvecs; ++i) WSABUF_FROM_EVBUFFER_IOV(&vecs[i], &ev_vecs[i]); #endif #ifdef _WIN32 { DWORD bytesRead; DWORD flags=0; if (WSARecv(fd, vecs, nvecs, &bytesRead, &flags, NULL, NULL)) { /* The read failed. It might be a close, * or it might be an error. */ if (WSAGetLastError() == WSAECONNABORTED) n = 0; else n = -1; } else n = bytesRead; } #else n = readv(fd, vecs, nvecs); #endif } #else /*!USE_IOVEC_IMPL*/ /* If we don't have FIONREAD, we might waste some space here */ /* XXX we _will_ waste some space here if there is any space left * over on buf->last. */ if ((chain = evbuffer_expand_singlechain(buf, howmuch)) == NULL) { result = -1; goto done; } /* We can append new data at this point */ p = chain->buffer + chain->misalign + chain->off; #ifndef _WIN32 n = read(fd, p, howmuch); #else n = recv(fd, p, howmuch, 0); #endif #endif /* USE_IOVEC_IMPL */ if (n == -1) { result = -1; goto done; } if (n == 0) { result = 0; goto done; } #ifdef USE_IOVEC_IMPL remaining = n; for (i=0; i < nvecs; ++i) { /* can't overflow, since only mutable chains have * huge misaligns. */ size_t space = (size_t) CHAIN_SPACE_LEN(*chainp); /* XXXX This is a kludge that can waste space in perverse * situations. */ if (space > EVBUFFER_CHAIN_MAX) space = EVBUFFER_CHAIN_MAX; if ((ev_ssize_t)space < remaining) { (*chainp)->off += space; remaining -= (int)space; } else { (*chainp)->off += remaining; buf->last_with_datap = chainp; break; } chainp = &(*chainp)->next; } #else chain->off += n; advance_last_with_data(buf); #endif buf->total_len += n; buf->n_add_for_cb += n; /* Tell someone about changes in this buffer */ evbuffer_invoke_callbacks_(buf); result = n; done: EVBUFFER_UNLOCK(buf); return result; } #ifdef USE_IOVEC_IMPL static inline int evbuffer_write_iovec(struct evbuffer *buffer, evutil_socket_t fd, ev_ssize_t howmuch) { IOV_TYPE iov[NUM_WRITE_IOVEC]; struct evbuffer_chain *chain = buffer->first; int n, i = 0; if (howmuch < 0) return -1; ASSERT_EVBUFFER_LOCKED(buffer); /* XXX make this top out at some maximal data length? if the * buffer has (say) 1MB in it, split over 128 chains, there's * no way it all gets written in one go. */ while (chain != NULL && i < NUM_WRITE_IOVEC && howmuch) { #ifdef USE_SENDFILE /* we cannot write the file info via writev */ if (chain->flags & EVBUFFER_SENDFILE) break; #endif iov[i].IOV_PTR_FIELD = (void *) (chain->buffer + chain->misalign); if ((size_t)howmuch >= chain->off) { /* XXXcould be problematic when windows supports mmap*/ iov[i++].IOV_LEN_FIELD = (IOV_LEN_TYPE)chain->off; howmuch -= chain->off; } else { /* XXXcould be problematic when windows supports mmap*/ iov[i++].IOV_LEN_FIELD = (IOV_LEN_TYPE)howmuch; break; } chain = chain->next; } if (! i) return 0; #ifdef _WIN32 { DWORD bytesSent; if (WSASend(fd, iov, i, &bytesSent, 0, NULL, NULL)) n = -1; else n = bytesSent; } #else n = writev(fd, iov, i); #endif return (n); } #endif #ifdef USE_SENDFILE static inline int evbuffer_write_sendfile(struct evbuffer *buffer, evutil_socket_t dest_fd, ev_ssize_t howmuch) { struct evbuffer_chain *chain = buffer->first; struct evbuffer_chain_file_segment *info = EVBUFFER_CHAIN_EXTRA(struct evbuffer_chain_file_segment, chain); const int source_fd = info->segment->fd; #if defined(SENDFILE_IS_MACOSX) || defined(SENDFILE_IS_FREEBSD) int res; ev_off_t len = chain->off; #elif defined(SENDFILE_IS_LINUX) || defined(SENDFILE_IS_SOLARIS) ev_ssize_t res; ev_off_t offset = chain->misalign; #endif ASSERT_EVBUFFER_LOCKED(buffer); #if defined(SENDFILE_IS_MACOSX) res = sendfile(source_fd, dest_fd, chain->misalign, &len, NULL, 0); if (res == -1 && !EVUTIL_ERR_RW_RETRIABLE(errno)) return (-1); return (len); #elif defined(SENDFILE_IS_FREEBSD) res = sendfile(source_fd, dest_fd, chain->misalign, chain->off, NULL, &len, 0); if (res == -1 && !EVUTIL_ERR_RW_RETRIABLE(errno)) return (-1); return (len); #elif defined(SENDFILE_IS_LINUX) /* TODO(niels): implement splice */ res = sendfile(dest_fd, source_fd, &offset, chain->off); if (res == -1 && EVUTIL_ERR_RW_RETRIABLE(errno)) { /* if this is EAGAIN or EINTR return 0; otherwise, -1 */ return (0); } return (res); #elif defined(SENDFILE_IS_SOLARIS) { const off_t offset_orig = offset; res = sendfile(dest_fd, source_fd, &offset, chain->off); if (res == -1 && EVUTIL_ERR_RW_RETRIABLE(errno)) { if (offset - offset_orig) return offset - offset_orig; /* if this is EAGAIN or EINTR and no bytes were * written, return 0 */ return (0); } return (res); } #endif } #endif int evbuffer_write_atmost(struct evbuffer *buffer, evutil_socket_t fd, ev_ssize_t howmuch) { int n = -1; EVBUFFER_LOCK(buffer); if (buffer->freeze_start) { goto done; } if (howmuch < 0 || (size_t)howmuch > buffer->total_len) howmuch = buffer->total_len; if (howmuch > 0) { #ifdef USE_SENDFILE struct evbuffer_chain *chain = buffer->first; if (chain != NULL && (chain->flags & EVBUFFER_SENDFILE)) n = evbuffer_write_sendfile(buffer, fd, howmuch); else { #endif #ifdef USE_IOVEC_IMPL n = evbuffer_write_iovec(buffer, fd, howmuch); #elif defined(_WIN32) /* XXX(nickm) Don't disable this code until we know if * the WSARecv code above works. */ void *p = evbuffer_pullup(buffer, howmuch); EVUTIL_ASSERT(p || !howmuch); n = send(fd, p, howmuch, 0); #else void *p = evbuffer_pullup(buffer, howmuch); EVUTIL_ASSERT(p || !howmuch); n = write(fd, p, howmuch); #endif #ifdef USE_SENDFILE } #endif } if (n > 0) evbuffer_drain(buffer, n); done: EVBUFFER_UNLOCK(buffer); return (n); } int evbuffer_write(struct evbuffer *buffer, evutil_socket_t fd) { return evbuffer_write_atmost(buffer, fd, -1); } unsigned char * evbuffer_find(struct evbuffer *buffer, const unsigned char *what, size_t len) { unsigned char *search; struct evbuffer_ptr ptr; EVBUFFER_LOCK(buffer); ptr = evbuffer_search(buffer, (const char *)what, len, NULL); if (ptr.pos < 0) { search = NULL; } else { search = evbuffer_pullup(buffer, ptr.pos + len); if (search) search += ptr.pos; } EVBUFFER_UNLOCK(buffer); return search; } /* Subract howfar from the position of pos within * buf. Returns 0 on success, -1 on failure. * * This isn't exposed yet, because of potential inefficiency issues. * Maybe it should be. */ static int evbuffer_ptr_subtract(struct evbuffer *buf, struct evbuffer_ptr *pos, size_t howfar) { if (pos->pos < 0) return -1; if (howfar > (size_t)pos->pos) return -1; if (pos->internal_.chain && howfar <= pos->internal_.pos_in_chain) { pos->internal_.pos_in_chain -= howfar; pos->pos -= howfar; return 0; } else { const size_t newpos = pos->pos - howfar; /* Here's the inefficient part: it walks over the * chains until we hit newpos. */ return evbuffer_ptr_set(buf, pos, newpos, EVBUFFER_PTR_SET); } } int evbuffer_ptr_set(struct evbuffer *buf, struct evbuffer_ptr *pos, size_t position, enum evbuffer_ptr_how how) { size_t left = position; struct evbuffer_chain *chain = NULL; int result = 0; EVBUFFER_LOCK(buf); switch (how) { case EVBUFFER_PTR_SET: chain = buf->first; pos->pos = position; position = 0; break; case EVBUFFER_PTR_ADD: /* this avoids iterating over all previous chains if we just want to advance the position */ if (pos->pos < 0 || EV_SIZE_MAX - position < (size_t)pos->pos) { EVBUFFER_UNLOCK(buf); return -1; } chain = pos->internal_.chain; pos->pos += position; position = pos->internal_.pos_in_chain; break; } EVUTIL_ASSERT(EV_SIZE_MAX - left >= position); while (chain && position + left >= chain->off) { left -= chain->off - position; chain = chain->next; position = 0; } if (chain) { pos->internal_.chain = chain; pos->internal_.pos_in_chain = position + left; } else if (left == 0) { /* The first byte in the (nonexistent) chain after the last chain */ pos->internal_.chain = NULL; pos->internal_.pos_in_chain = 0; } else { PTR_NOT_FOUND(pos); result = -1; } EVBUFFER_UNLOCK(buf); return result; } /** Compare the bytes in buf at position pos to the len bytes in mem. Return less than 0, 0, or greater than 0 as memcmp. */ static int evbuffer_ptr_memcmp(const struct evbuffer *buf, const struct evbuffer_ptr *pos, const char *mem, size_t len) { struct evbuffer_chain *chain; size_t position; int r; ASSERT_EVBUFFER_LOCKED(buf); if (pos->pos < 0 || EV_SIZE_MAX - len < (size_t)pos->pos || pos->pos + len > buf->total_len) return -1; chain = pos->internal_.chain; position = pos->internal_.pos_in_chain; while (len && chain) { size_t n_comparable; if (len + position > chain->off) n_comparable = chain->off - position; else n_comparable = len; r = memcmp(chain->buffer + chain->misalign + position, mem, n_comparable); if (r) return r; mem += n_comparable; len -= n_comparable; position = 0; chain = chain->next; } return 0; } struct evbuffer_ptr evbuffer_search(struct evbuffer *buffer, const char *what, size_t len, const struct evbuffer_ptr *start) { return evbuffer_search_range(buffer, what, len, start, NULL); } struct evbuffer_ptr evbuffer_search_range(struct evbuffer *buffer, const char *what, size_t len, const struct evbuffer_ptr *start, const struct evbuffer_ptr *end) { struct evbuffer_ptr pos; struct evbuffer_chain *chain, *last_chain = NULL; const unsigned char *p; char first; EVBUFFER_LOCK(buffer); if (start) { memcpy(&pos, start, sizeof(pos)); chain = pos.internal_.chain; } else { pos.pos = 0; chain = pos.internal_.chain = buffer->first; pos.internal_.pos_in_chain = 0; } if (end) last_chain = end->internal_.chain; if (!len || len > EV_SSIZE_MAX) goto done; first = what[0]; while (chain) { const unsigned char *start_at = chain->buffer + chain->misalign + pos.internal_.pos_in_chain; p = memchr(start_at, first, chain->off - pos.internal_.pos_in_chain); if (p) { pos.pos += p - start_at; pos.internal_.pos_in_chain += p - start_at; if (!evbuffer_ptr_memcmp(buffer, &pos, what, len)) { if (end && pos.pos + (ev_ssize_t)len > end->pos) goto not_found; else goto done; } ++pos.pos; ++pos.internal_.pos_in_chain; if (pos.internal_.pos_in_chain == chain->off) { chain = pos.internal_.chain = chain->next; pos.internal_.pos_in_chain = 0; } } else { if (chain == last_chain) goto not_found; pos.pos += chain->off - pos.internal_.pos_in_chain; chain = pos.internal_.chain = chain->next; pos.internal_.pos_in_chain = 0; } } not_found: PTR_NOT_FOUND(&pos); done: EVBUFFER_UNLOCK(buffer); return pos; } int evbuffer_peek(struct evbuffer *buffer, ev_ssize_t len, struct evbuffer_ptr *start_at, struct evbuffer_iovec *vec, int n_vec) { struct evbuffer_chain *chain; int idx = 0; ev_ssize_t len_so_far = 0; /* Avoid locking in trivial edge cases */ if (start_at && start_at->internal_.chain == NULL) return 0; EVBUFFER_LOCK(buffer); if (start_at) { chain = start_at->internal_.chain; len_so_far = chain->off - start_at->internal_.pos_in_chain; idx = 1; if (n_vec > 0) { vec[0].iov_base = chain->buffer + chain->misalign + start_at->internal_.pos_in_chain; vec[0].iov_len = len_so_far; } chain = chain->next; } else { chain = buffer->first; } if (n_vec == 0 && len < 0) { /* If no vectors are provided and they asked for "everything", * pretend they asked for the actual available amount. */ len = buffer->total_len; if (start_at) { len -= start_at->pos; } } while (chain) { if (len >= 0 && len_so_far >= len) break; if (idxbuffer + chain->misalign; vec[idx].iov_len = chain->off; } else if (len<0) { break; } ++idx; len_so_far += chain->off; chain = chain->next; } EVBUFFER_UNLOCK(buffer); return idx; } int evbuffer_add_vprintf(struct evbuffer *buf, const char *fmt, va_list ap) { char *buffer; size_t space; int sz, result = -1; va_list aq; struct evbuffer_chain *chain; EVBUFFER_LOCK(buf); if (buf->freeze_end) { goto done; } /* make sure that at least some space is available */ if ((chain = evbuffer_expand_singlechain(buf, 64)) == NULL) goto done; for (;;) { #if 0 size_t used = chain->misalign + chain->off; buffer = (char *)chain->buffer + chain->misalign + chain->off; EVUTIL_ASSERT(chain->buffer_len >= used); space = chain->buffer_len - used; #endif buffer = (char*) CHAIN_SPACE_PTR(chain); space = (size_t) CHAIN_SPACE_LEN(chain); #ifndef va_copy #define va_copy(dst, src) memcpy(&(dst), &(src), sizeof(va_list)) #endif va_copy(aq, ap); sz = evutil_vsnprintf(buffer, space, fmt, aq); va_end(aq); if (sz < 0) goto done; if (INT_MAX >= EVBUFFER_CHAIN_MAX && (size_t)sz >= EVBUFFER_CHAIN_MAX) goto done; if ((size_t)sz < space) { chain->off += sz; buf->total_len += sz; buf->n_add_for_cb += sz; advance_last_with_data(buf); evbuffer_invoke_callbacks_(buf); result = sz; goto done; } if ((chain = evbuffer_expand_singlechain(buf, sz + 1)) == NULL) goto done; } /* NOTREACHED */ done: EVBUFFER_UNLOCK(buf); return result; } int evbuffer_add_printf(struct evbuffer *buf, const char *fmt, ...) { int res = -1; va_list ap; va_start(ap, fmt); res = evbuffer_add_vprintf(buf, fmt, ap); va_end(ap); return (res); } int evbuffer_add_reference(struct evbuffer *outbuf, const void *data, size_t datlen, evbuffer_ref_cleanup_cb cleanupfn, void *extra) { struct evbuffer_chain *chain; struct evbuffer_chain_reference *info; int result = -1; chain = evbuffer_chain_new(sizeof(struct evbuffer_chain_reference)); if (!chain) return (-1); chain->flags |= EVBUFFER_REFERENCE | EVBUFFER_IMMUTABLE; chain->buffer = (unsigned char *)data; chain->buffer_len = datlen; chain->off = datlen; info = EVBUFFER_CHAIN_EXTRA(struct evbuffer_chain_reference, chain); info->cleanupfn = cleanupfn; info->extra = extra; EVBUFFER_LOCK(outbuf); if (outbuf->freeze_end) { /* don't call chain_free; we do not want to actually invoke * the cleanup function */ mm_free(chain); goto done; } evbuffer_chain_insert(outbuf, chain); outbuf->n_add_for_cb += datlen; evbuffer_invoke_callbacks_(outbuf); result = 0; done: EVBUFFER_UNLOCK(outbuf); return result; } /* TODO(niels): we may want to add to automagically convert to mmap, in * case evbuffer_remove() or evbuffer_pullup() are being used. */ struct evbuffer_file_segment * evbuffer_file_segment_new( int fd, ev_off_t offset, ev_off_t length, unsigned flags) { struct evbuffer_file_segment *seg = mm_calloc(sizeof(struct evbuffer_file_segment), 1); if (!seg) return NULL; seg->refcnt = 1; seg->fd = fd; seg->flags = flags; seg->file_offset = offset; seg->cleanup_cb = NULL; seg->cleanup_cb_arg = NULL; #ifdef _WIN32 #ifndef lseek #define lseek _lseeki64 #endif #ifndef fstat #define fstat _fstat #endif #ifndef stat #define stat _stat #endif #endif if (length == -1) { struct stat st; if (fstat(fd, &st) < 0) goto err; length = st.st_size; } seg->length = length; if (offset < 0 || length < 0 || ((ev_uint64_t)length > EVBUFFER_CHAIN_MAX) || (ev_uint64_t)offset > (ev_uint64_t)(EVBUFFER_CHAIN_MAX - length)) goto err; #if defined(USE_SENDFILE) if (!(flags & EVBUF_FS_DISABLE_SENDFILE)) { seg->can_sendfile = 1; goto done; } #endif if (evbuffer_file_segment_materialize(seg)<0) goto err; #if defined(USE_SENDFILE) done: #endif if (!(flags & EVBUF_FS_DISABLE_LOCKING)) { EVTHREAD_ALLOC_LOCK(seg->lock, 0); } return seg; err: mm_free(seg); return NULL; } #ifdef EVENT__HAVE_MMAP static long get_page_size(void) { #ifdef SC_PAGE_SIZE return sysconf(SC_PAGE_SIZE); #elif defined(_SC_PAGE_SIZE) return sysconf(_SC_PAGE_SIZE); #else return 1; #endif } #endif /* DOCDOC */ /* Requires lock */ static int evbuffer_file_segment_materialize(struct evbuffer_file_segment *seg) { const unsigned flags = seg->flags; const int fd = seg->fd; const ev_off_t length = seg->length; const ev_off_t offset = seg->file_offset; if (seg->contents) return 0; /* already materialized */ #if defined(EVENT__HAVE_MMAP) if (!(flags & EVBUF_FS_DISABLE_MMAP)) { off_t offset_rounded = 0, offset_leftover = 0; void *mapped; if (offset) { /* mmap implementations don't generally like us * to have an offset that isn't a round */ long page_size = get_page_size(); if (page_size == -1) goto err; offset_leftover = offset % page_size; offset_rounded = offset - offset_leftover; } mapped = mmap(NULL, length + offset_leftover, PROT_READ, #ifdef MAP_NOCACHE MAP_NOCACHE | /* ??? */ #endif #ifdef MAP_FILE MAP_FILE | #endif MAP_PRIVATE, fd, offset_rounded); if (mapped == MAP_FAILED) { event_warn("%s: mmap(%d, %d, %zu) failed", __func__, fd, 0, (size_t)(offset + length)); } else { seg->mapping = mapped; seg->contents = (char*)mapped+offset_leftover; seg->mmap_offset = 0; seg->is_mapping = 1; goto done; } } #endif #ifdef _WIN32 if (!(flags & EVBUF_FS_DISABLE_MMAP)) { intptr_t h = _get_osfhandle(fd); HANDLE m; ev_uint64_t total_size = length+offset; if ((HANDLE)h == INVALID_HANDLE_VALUE) goto err; m = CreateFileMapping((HANDLE)h, NULL, PAGE_READONLY, (total_size >> 32), total_size & 0xfffffffful, NULL); if (m != INVALID_HANDLE_VALUE) { /* Does h leak? */ seg->mapping_handle = m; seg->mmap_offset = offset; seg->is_mapping = 1; goto done; } } #endif { ev_off_t start_pos = lseek(fd, 0, SEEK_CUR), pos; ev_off_t read_so_far = 0; char *mem; int e; ev_ssize_t n = 0; if (!(mem = mm_malloc(length))) goto err; if (start_pos < 0) { mm_free(mem); goto err; } if (lseek(fd, offset, SEEK_SET) < 0) { mm_free(mem); goto err; } while (read_so_far < length) { n = read(fd, mem+read_so_far, length-read_so_far); if (n <= 0) break; read_so_far += n; } e = errno; pos = lseek(fd, start_pos, SEEK_SET); if (n < 0 || (n == 0 && length > read_so_far)) { mm_free(mem); errno = e; goto err; } else if (pos < 0) { mm_free(mem); goto err; } seg->contents = mem; } done: return 0; err: return -1; } void evbuffer_file_segment_add_cleanup_cb(struct evbuffer_file_segment *seg, evbuffer_file_segment_cleanup_cb cb, void* arg) { EVUTIL_ASSERT(seg->refcnt > 0); seg->cleanup_cb = cb; seg->cleanup_cb_arg = arg; } void evbuffer_file_segment_free(struct evbuffer_file_segment *seg) { int refcnt; EVLOCK_LOCK(seg->lock, 0); refcnt = --seg->refcnt; EVLOCK_UNLOCK(seg->lock, 0); if (refcnt > 0) return; EVUTIL_ASSERT(refcnt == 0); if (seg->is_mapping) { #ifdef _WIN32 CloseHandle(seg->mapping_handle); #elif defined (EVENT__HAVE_MMAP) off_t offset_leftover; offset_leftover = seg->file_offset % get_page_size(); if (munmap(seg->mapping, seg->length + offset_leftover) == -1) event_warn("%s: munmap failed", __func__); #endif } else if (seg->contents) { mm_free(seg->contents); } if ((seg->flags & EVBUF_FS_CLOSE_ON_FREE) && seg->fd >= 0) { close(seg->fd); } if (seg->cleanup_cb) { (*seg->cleanup_cb)((struct evbuffer_file_segment const*)seg, seg->flags, seg->cleanup_cb_arg); seg->cleanup_cb = NULL; seg->cleanup_cb_arg = NULL; } EVTHREAD_FREE_LOCK(seg->lock, 0); mm_free(seg); } int evbuffer_add_file_segment(struct evbuffer *buf, struct evbuffer_file_segment *seg, ev_off_t offset, ev_off_t length) { struct evbuffer_chain *chain; struct evbuffer_chain_file_segment *extra; int can_use_sendfile = 0; EVBUFFER_LOCK(buf); EVLOCK_LOCK(seg->lock, 0); if (buf->flags & EVBUFFER_FLAG_DRAINS_TO_FD) { can_use_sendfile = 1; } else { if (!seg->contents) { if (evbuffer_file_segment_materialize(seg)<0) { EVLOCK_UNLOCK(seg->lock, 0); EVBUFFER_UNLOCK(buf); return -1; } } } ++seg->refcnt; EVLOCK_UNLOCK(seg->lock, 0); if (buf->freeze_end) goto err; if (length < 0) { if (offset > seg->length) goto err; length = seg->length - offset; } /* Can we actually add this? */ if (offset+length > seg->length) goto err; chain = evbuffer_chain_new(sizeof(struct evbuffer_chain_file_segment)); if (!chain) goto err; extra = EVBUFFER_CHAIN_EXTRA(struct evbuffer_chain_file_segment, chain); chain->flags |= EVBUFFER_IMMUTABLE|EVBUFFER_FILESEGMENT; if (can_use_sendfile && seg->can_sendfile) { chain->flags |= EVBUFFER_SENDFILE; chain->misalign = seg->file_offset + offset; chain->off = length; chain->buffer_len = chain->misalign + length; } else if (seg->is_mapping) { #ifdef _WIN32 ev_uint64_t total_offset = seg->mmap_offset+offset; ev_uint64_t offset_rounded=0, offset_remaining=0; LPVOID data; if (total_offset) { SYSTEM_INFO si; memset(&si, 0, sizeof(si)); /* cargo cult */ GetSystemInfo(&si); offset_remaining = total_offset % si.dwAllocationGranularity; offset_rounded = total_offset - offset_remaining; } data = MapViewOfFile( seg->mapping_handle, FILE_MAP_READ, offset_rounded >> 32, offset_rounded & 0xfffffffful, length + offset_remaining); if (data == NULL) { mm_free(chain); goto err; } chain->buffer = (unsigned char*) data; chain->buffer_len = length+offset_remaining; chain->misalign = offset_remaining; chain->off = length; #else chain->buffer = (unsigned char*)(seg->contents + offset); chain->buffer_len = length; chain->off = length; #endif } else { chain->buffer = (unsigned char*)(seg->contents + offset); chain->buffer_len = length; chain->off = length; } extra->segment = seg; buf->n_add_for_cb += length; evbuffer_chain_insert(buf, chain); evbuffer_invoke_callbacks_(buf); EVBUFFER_UNLOCK(buf); return 0; err: EVBUFFER_UNLOCK(buf); evbuffer_file_segment_free(seg); /* Lowers the refcount */ return -1; } int evbuffer_add_file(struct evbuffer *buf, int fd, ev_off_t offset, ev_off_t length) { struct evbuffer_file_segment *seg; unsigned flags = EVBUF_FS_CLOSE_ON_FREE; int r; seg = evbuffer_file_segment_new(fd, offset, length, flags); if (!seg) return -1; r = evbuffer_add_file_segment(buf, seg, 0, length); if (r == 0) evbuffer_file_segment_free(seg); return r; } void evbuffer_setcb(struct evbuffer *buffer, evbuffer_cb cb, void *cbarg) { EVBUFFER_LOCK(buffer); if (!LIST_EMPTY(&buffer->callbacks)) evbuffer_remove_all_callbacks(buffer); if (cb) { struct evbuffer_cb_entry *ent = evbuffer_add_cb(buffer, NULL, cbarg); ent->cb.cb_obsolete = cb; ent->flags |= EVBUFFER_CB_OBSOLETE; } EVBUFFER_UNLOCK(buffer); } struct evbuffer_cb_entry * evbuffer_add_cb(struct evbuffer *buffer, evbuffer_cb_func cb, void *cbarg) { struct evbuffer_cb_entry *e; if (! (e = mm_calloc(1, sizeof(struct evbuffer_cb_entry)))) return NULL; EVBUFFER_LOCK(buffer); e->cb.cb_func = cb; e->cbarg = cbarg; e->flags = EVBUFFER_CB_ENABLED; LIST_INSERT_HEAD(&buffer->callbacks, e, next); EVBUFFER_UNLOCK(buffer); return e; } int evbuffer_remove_cb_entry(struct evbuffer *buffer, struct evbuffer_cb_entry *ent) { EVBUFFER_LOCK(buffer); LIST_REMOVE(ent, next); EVBUFFER_UNLOCK(buffer); mm_free(ent); return 0; } int evbuffer_remove_cb(struct evbuffer *buffer, evbuffer_cb_func cb, void *cbarg) { struct evbuffer_cb_entry *cbent; int result = -1; EVBUFFER_LOCK(buffer); LIST_FOREACH(cbent, &buffer->callbacks, next) { if (cb == cbent->cb.cb_func && cbarg == cbent->cbarg) { result = evbuffer_remove_cb_entry(buffer, cbent); goto done; } } done: EVBUFFER_UNLOCK(buffer); return result; } int evbuffer_cb_set_flags(struct evbuffer *buffer, struct evbuffer_cb_entry *cb, ev_uint32_t flags) { /* the user isn't allowed to mess with these. */ flags &= ~EVBUFFER_CB_INTERNAL_FLAGS; EVBUFFER_LOCK(buffer); cb->flags |= flags; EVBUFFER_UNLOCK(buffer); return 0; } int evbuffer_cb_clear_flags(struct evbuffer *buffer, struct evbuffer_cb_entry *cb, ev_uint32_t flags) { /* the user isn't allowed to mess with these. */ flags &= ~EVBUFFER_CB_INTERNAL_FLAGS; EVBUFFER_LOCK(buffer); cb->flags &= ~flags; EVBUFFER_UNLOCK(buffer); return 0; } int evbuffer_freeze(struct evbuffer *buffer, int start) { EVBUFFER_LOCK(buffer); if (start) buffer->freeze_start = 1; else buffer->freeze_end = 1; EVBUFFER_UNLOCK(buffer); return 0; } int evbuffer_unfreeze(struct evbuffer *buffer, int start) { EVBUFFER_LOCK(buffer); if (start) buffer->freeze_start = 0; else buffer->freeze_end = 0; EVBUFFER_UNLOCK(buffer); return 0; } #if 0 void evbuffer_cb_suspend(struct evbuffer *buffer, struct evbuffer_cb_entry *cb) { if (!(cb->flags & EVBUFFER_CB_SUSPENDED)) { cb->size_before_suspend = evbuffer_get_length(buffer); cb->flags |= EVBUFFER_CB_SUSPENDED; } } void evbuffer_cb_unsuspend(struct evbuffer *buffer, struct evbuffer_cb_entry *cb) { if ((cb->flags & EVBUFFER_CB_SUSPENDED)) { unsigned call = (cb->flags & EVBUFFER_CB_CALL_ON_UNSUSPEND); size_t sz = cb->size_before_suspend; cb->flags &= ~(EVBUFFER_CB_SUSPENDED| EVBUFFER_CB_CALL_ON_UNSUSPEND); cb->size_before_suspend = 0; if (call && (cb->flags & EVBUFFER_CB_ENABLED)) { cb->cb(buffer, sz, evbuffer_get_length(buffer), cb->cbarg); } } } #endif int evbuffer_get_callbacks_(struct evbuffer *buffer, struct event_callback **cbs, int max_cbs) { int r = 0; EVBUFFER_LOCK(buffer); if (buffer->deferred_cbs) { if (max_cbs < 1) { r = -1; goto done; } cbs[0] = &buffer->deferred; r = 1; } done: EVBUFFER_UNLOCK(buffer); return r; }