/* * libkmod - interface to kernel module operations * * Copyright (C) 2011-2013 ProFUSION embedded systems * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ #include /* htonl */ #include #include #include #include #include #include #include #include "libkmod-private.h" #include "libkmod-index.h" #include "macro.h" /* index.c: module index file shared functions for modprobe and depmod */ #define INDEX_CHILDMAX 128 /* Disk format: uint32_t magic = INDEX_MAGIC; uint32_t version = INDEX_VERSION; uint32_t root_offset; (node_offset & INDEX_NODE_MASK) specifies the file offset of nodes: char[] prefix; // nul terminated char first; char last; uint32_t children[last - first + 1]; uint32_t value_count; struct { uint32_t priority; char[] value; // nul terminated } values[value_count]; (node_offset & INDEX_NODE_FLAGS) indicates which fields are present. Empty prefixes are omitted, leaf nodes omit the three child-related fields. This could be optimised further by adding a sparse child format (indicated using a new flag). */ /* Format of node offsets within index file */ enum node_offset { INDEX_NODE_FLAGS = 0xF0000000, /* Flags in high nibble */ INDEX_NODE_PREFIX = 0x80000000, INDEX_NODE_VALUES = 0x40000000, INDEX_NODE_CHILDS = 0x20000000, INDEX_NODE_MASK = 0x0FFFFFFF, /* Offset value */ }; void index_values_free(struct index_value *values) { while (values) { struct index_value *value = values; values = value->next; free(value); } } static int add_value(struct index_value **values, const char *value, unsigned len, unsigned int priority) { struct index_value *v; /* find position to insert value */ while (*values && (*values)->priority < priority) values = &(*values)->next; v = malloc(sizeof(struct index_value) + len + 1); if (!v) return -1; v->next = *values; v->priority = priority; v->len = len; memcpy(v->value, value, len); v->value[len] = '\0'; *values = v; return 0; } static void read_error(void) { fatal("Module index: unexpected error: %s\n" "Try re-running depmod\n", errno ? strerror(errno) : "EOF"); } static int read_char(FILE *in) { int ch; errno = 0; ch = getc_unlocked(in); if (ch == EOF) read_error(); return ch; } static uint32_t read_long(FILE *in) { uint32_t l; errno = 0; if (fread(&l, sizeof(uint32_t), 1, in) <= 0) read_error(); return ntohl(l); } /* * Buffer abstract data type * * Used internally to store the current path during tree traversal. * They help build wildcard key strings to pass to fnmatch(), * as well as building values of matching keys. */ struct buffer { char *bytes; unsigned size; unsigned used; }; #define BUF_STEP (2048) static bool buf_grow(struct buffer *buf, size_t newsize) { void *tmp; size_t sz; if (newsize % BUF_STEP == 0) sz = newsize; else sz = ((newsize / BUF_STEP) + 1) * BUF_STEP; if (buf->size == sz) return true; tmp = realloc(buf->bytes, sz); if (sz > 0 && tmp == NULL) return false; buf->bytes = tmp; buf->size = sz; return true; } static void buf_init(struct buffer *buf) { buf->bytes = NULL; buf->size = 0; buf->used = 0; } static void buf_release(struct buffer *buf) { free(buf->bytes); } /* Destroy buffer and return a copy as a C string */ static char *buf_steal(struct buffer *buf) { char *bytes; bytes = realloc(buf->bytes, buf->used + 1); if (!bytes) { free(buf->bytes); return NULL; } bytes[buf->used] = '\0'; return bytes; } /* Return a C string owned by the buffer (invalidated if the buffer is changed). */ static const char *buf_str(struct buffer *buf) { if (!buf_grow(buf, buf->used + 1)) return NULL; buf->bytes[buf->used] = '\0'; return buf->bytes; } static bool buf_pushchar(struct buffer *buf, char ch) { if (!buf_grow(buf, buf->used + 1)) return false; buf->bytes[buf->used] = ch; buf->used++; return true; } static unsigned buf_pushchars(struct buffer *buf, const char *str) { unsigned i = 0; int ch; while ((ch = str[i])) { buf_pushchar(buf, ch); i++; } return i; } static unsigned buf_freadchars(struct buffer *buf, FILE *in) { unsigned i = 0; int ch; while ((ch = read_char(in))) { if (!buf_pushchar(buf, ch)) break; i++; } return i; } static void buf_popchar(struct buffer *buf) { assert(buf->used > 0); buf->used--; } static void buf_popchars(struct buffer *buf, unsigned n) { assert(buf->used >= n); buf->used -= n; } static void buf_clear(struct buffer *buf) { buf->used = 0; } /* * Index file searching */ struct index_node_f { FILE *file; char *prefix; /* path compression */ struct index_value *values; unsigned char first; /* range of child nodes */ unsigned char last; uint32_t children[0]; }; static struct index_node_f *index_read(FILE *in, uint32_t offset) { struct index_node_f *node; char *prefix; int i, child_count = 0; if ((offset & INDEX_NODE_MASK) == 0) return NULL; fseek(in, offset & INDEX_NODE_MASK, SEEK_SET); if (offset & INDEX_NODE_PREFIX) { struct buffer buf; buf_init(&buf); buf_freadchars(&buf, in); prefix = buf_steal(&buf); } else prefix = NOFAIL(strdup("")); if (offset & INDEX_NODE_CHILDS) { char first = read_char(in); char last = read_char(in); child_count = last - first + 1; node = NOFAIL(malloc(sizeof(struct index_node_f) + sizeof(uint32_t) * child_count)); node->first = first; node->last = last; for (i = 0; i < child_count; i++) node->children[i] = read_long(in); } else { node = NOFAIL(malloc(sizeof(struct index_node_f))); node->first = INDEX_CHILDMAX; node->last = 0; } node->values = NULL; if (offset & INDEX_NODE_VALUES) { int value_count; struct buffer buf; const char *value; unsigned int priority; value_count = read_long(in); buf_init(&buf); while (value_count--) { priority = read_long(in); buf_freadchars(&buf, in); value = buf_str(&buf); add_value(&node->values, value, buf.used, priority); buf_clear(&buf); } buf_release(&buf); } node->prefix = prefix; node->file = in; return node; } static void index_close(struct index_node_f *node) { free(node->prefix); index_values_free(node->values); free(node); } struct index_file { FILE *file; uint32_t root_offset; }; /* Failures are silent; modprobe will fall back to text files */ struct index_file *index_file_open(const char *filename) { FILE *file; uint32_t magic, version; struct index_file *new; file = fopen(filename, "re"); if (!file) return NULL; errno = EINVAL; magic = read_long(file); if (magic != INDEX_MAGIC) { fclose(file); return NULL; } version = read_long(file); if (version >> 16 != INDEX_VERSION_MAJOR) { fclose(file); return NULL; } new = NOFAIL(malloc(sizeof(struct index_file))); new->file = file; new->root_offset = read_long(new->file); errno = 0; return new; } void index_file_close(struct index_file *idx) { fclose(idx->file); free(idx); } static struct index_node_f *index_readroot(struct index_file *in) { return index_read(in->file, in->root_offset); } static struct index_node_f *index_readchild(const struct index_node_f *parent, int ch) { if (parent->first <= ch && ch <= parent->last) { return index_read(parent->file, parent->children[ch - parent->first]); } return NULL; } static void index_dump_node(struct index_node_f *node, struct buffer *buf, int fd) { struct index_value *v; int ch, pushed; pushed = buf_pushchars(buf, node->prefix); for (v = node->values; v != NULL; v = v->next) { write_str_safe(fd, buf->bytes, buf->used); write_str_safe(fd, " ", 1); write_str_safe(fd, v->value, strlen(v->value)); write_str_safe(fd, "\n", 1); } for (ch = node->first; ch <= node->last; ch++) { struct index_node_f *child = index_readchild(node, ch); if (!child) continue; buf_pushchar(buf, ch); index_dump_node(child, buf, fd); buf_popchar(buf); } buf_popchars(buf, pushed); index_close(node); } void index_dump(struct index_file *in, int fd, const char *prefix) { struct index_node_f *root; struct buffer buf; root = index_readroot(in); if (root == NULL) return; buf_init(&buf); buf_pushchars(&buf, prefix); index_dump_node(root, &buf, fd); buf_release(&buf); } static char *index_search__node(struct index_node_f *node, const char *key, int i) { char *value; struct index_node_f *child; int ch; int j; while(node) { for (j = 0; node->prefix[j]; j++) { ch = node->prefix[j]; if (ch != key[i+j]) { index_close(node); return NULL; } } i += j; if (key[i] == '\0') { value = node->values != NULL ? strdup(node->values[0].value) : NULL; index_close(node); return value; } child = index_readchild(node, key[i]); index_close(node); node = child; i++; } return NULL; } /* * Search the index for a key * * Returns the value of the first match * * The recursive functions free their node argument (using index_close). */ char *index_search(struct index_file *in, const char *key) { // FIXME: return value by reference instead of strdup struct index_node_f *root; char *value; root = index_readroot(in); value = index_search__node(root, key, 0); return value; } /* Level 4: add all the values from a matching node */ static void index_searchwild__allvalues(struct index_node_f *node, struct index_value **out) { struct index_value *v; for (v = node->values; v != NULL; v = v->next) add_value(out, v->value, v->len, v->priority); index_close(node); } /* * Level 3: traverse a sub-keyspace which starts with a wildcard, * looking for matches. */ static void index_searchwild__all(struct index_node_f *node, int j, struct buffer *buf, const char *subkey, struct index_value **out) { int pushed = 0; int ch; while (node->prefix[j]) { ch = node->prefix[j]; buf_pushchar(buf, ch); pushed++; j++; } for (ch = node->first; ch <= node->last; ch++) { struct index_node_f *child = index_readchild(node, ch); if (!child) continue; buf_pushchar(buf, ch); index_searchwild__all(child, 0, buf, subkey, out); buf_popchar(buf); } if (node->values) { if (fnmatch(buf_str(buf), subkey, 0) == 0) index_searchwild__allvalues(node, out); else index_close(node); } else { index_close(node); } buf_popchars(buf, pushed); } /* Level 2: descend the tree (until we hit a wildcard) */ static void index_searchwild__node(struct index_node_f *node, struct buffer *buf, const char *key, int i, struct index_value **out) { struct index_node_f *child; int j; int ch; while(node) { for (j = 0; node->prefix[j]; j++) { ch = node->prefix[j]; if (ch == '*' || ch == '?' || ch == '[') { index_searchwild__all(node, j, buf, &key[i+j], out); return; } if (ch != key[i+j]) { index_close(node); return; } } i += j; child = index_readchild(node, '*'); if (child) { buf_pushchar(buf, '*'); index_searchwild__all(child, 0, buf, &key[i], out); buf_popchar(buf); } child = index_readchild(node, '?'); if (child) { buf_pushchar(buf, '?'); index_searchwild__all(child, 0, buf, &key[i], out); buf_popchar(buf); } child = index_readchild(node, '['); if (child) { buf_pushchar(buf, '['); index_searchwild__all(child, 0, buf, &key[i], out); buf_popchar(buf); } if (key[i] == '\0') { index_searchwild__allvalues(node, out); return; } child = index_readchild(node, key[i]); index_close(node); node = child; i++; } } /* * Search the index for a key. The index may contain wildcards. * * Returns a list of all the values of matching keys. */ struct index_value *index_searchwild(struct index_file *in, const char *key) { struct index_node_f *root = index_readroot(in); struct buffer buf; struct index_value *out = NULL; buf_init(&buf); index_searchwild__node(root, &buf, key, 0, &out); buf_release(&buf); return out; } #include #include #include static const char _idx_empty_str[] = ""; /**************************************************************************/ /* * Alternative implementation, using mmap to map all the file to memory when * starting */ struct index_mm { struct kmod_ctx *ctx; void *mm; uint32_t root_offset; size_t size; }; struct index_mm_value { unsigned int priority; unsigned int len; const char *value; }; struct index_mm_value_array { struct index_mm_value *values; unsigned int len; }; struct index_mm_node { struct index_mm *idx; const char *prefix; /* mmape'd value */ struct index_mm_value_array values; unsigned char first; unsigned char last; uint32_t children[]; }; static inline uint32_t read_long_mm(void **p) { uint8_t *addr = *(uint8_t **)p; uint32_t v; /* addr may be unalined to uint32_t */ v = get_unaligned((uint32_t *) addr); *p = addr + sizeof(uint32_t); return ntohl(v); } static inline uint8_t read_char_mm(void **p) { uint8_t *addr = *(uint8_t **)p; uint8_t v = *addr; *p = addr + sizeof(uint8_t); return v; } static inline char *read_chars_mm(void **p, unsigned *rlen) { char *addr = *(char **)p; size_t len = *rlen = strlen(addr); *p = addr + len + 1; return addr; } static struct index_mm_node *index_mm_read_node(struct index_mm *idx, uint32_t offset) { void *p = idx->mm; struct index_mm_node *node; const char *prefix; int i, child_count, value_count, children_padding; uint32_t children[INDEX_CHILDMAX]; char first, last; if ((offset & INDEX_NODE_MASK) == 0) return NULL; p = (char *)p + (offset & INDEX_NODE_MASK); if (offset & INDEX_NODE_PREFIX) { unsigned len; prefix = read_chars_mm(&p, &len); } else prefix = _idx_empty_str; if (offset & INDEX_NODE_CHILDS) { first = read_char_mm(&p); last = read_char_mm(&p); child_count = last - first + 1; for (i = 0; i < child_count; i++) children[i] = read_long_mm(&p); } else { first = INDEX_CHILDMAX; last = 0; child_count = 0; } children_padding = (sizeof(struct index_mm_node) + (sizeof(uint32_t) * child_count)) % sizeof(void *); if (offset & INDEX_NODE_VALUES) value_count = read_long_mm(&p); else value_count = 0; node = malloc(sizeof(struct index_mm_node) + sizeof(uint32_t) * child_count + children_padding + sizeof(struct index_mm_value) * value_count); if (node == NULL) return NULL; node->idx = idx; node->prefix = prefix; if (value_count == 0) node->values.values = NULL; else { node->values.values = (struct index_mm_value *) ((char *)node + sizeof(struct index_mm_node) + sizeof(uint32_t) * child_count + children_padding); } node->values.len = value_count; node->first = first; node->last = last; memcpy(node->children, children, sizeof(uint32_t) * child_count); for (i = 0; i < value_count; i++) { struct index_mm_value *v = node->values.values + i; v->priority = read_long_mm(&p); v->value = read_chars_mm(&p, &v->len); } return node; } static void index_mm_free_node(struct index_mm_node *node) { free(node); } struct index_mm *index_mm_open(struct kmod_ctx *ctx, const char *filename, unsigned long long *stamp) { int fd; struct stat st; struct index_mm *idx; struct { uint32_t magic; uint32_t version; uint32_t root_offset; } hdr; void *p; DBG(ctx, "file=%s\n", filename); idx = malloc(sizeof(*idx)); if (idx == NULL) { ERR(ctx, "malloc: %m\n"); return NULL; } if ((fd = open(filename, O_RDONLY|O_CLOEXEC)) < 0) { DBG(ctx, "open(%s, O_RDONLY|O_CLOEXEC): %m\n", filename); goto fail_open; } fstat(fd, &st); if ((size_t) st.st_size < sizeof(hdr)) goto fail_nommap; if ((idx->mm = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0)) == MAP_FAILED) { ERR(ctx, "mmap(NULL, %"PRIu64", PROT_READ, %d, MAP_PRIVATE, 0): %m\n", st.st_size, fd); goto fail_nommap; } p = idx->mm; hdr.magic = read_long_mm(&p); hdr.version = read_long_mm(&p); hdr.root_offset = read_long_mm(&p); if (hdr.magic != INDEX_MAGIC) { ERR(ctx, "magic check fail: %x instead of %x\n", hdr.magic, INDEX_MAGIC); goto fail; } if (hdr.version >> 16 != INDEX_VERSION_MAJOR) { ERR(ctx, "major version check fail: %u instead of %u\n", hdr.version, INDEX_MAGIC); goto fail; } idx->root_offset = hdr.root_offset; idx->size = st.st_size; idx->ctx = ctx; close(fd); *stamp = stat_mstamp(&st); return idx; fail: munmap(idx->mm, st.st_size); fail_nommap: close(fd); fail_open: free(idx); return NULL; } void index_mm_close(struct index_mm *idx) { munmap(idx->mm, idx->size); free(idx); } static struct index_mm_node *index_mm_readroot(struct index_mm *idx) { return index_mm_read_node(idx, idx->root_offset); } static struct index_mm_node *index_mm_readchild(const struct index_mm_node *parent, int ch) { if (parent->first <= ch && ch <= parent->last) { return index_mm_read_node(parent->idx, parent->children[ch - parent->first]); } return NULL; } static void index_mm_dump_node(struct index_mm_node *node, struct buffer *buf, int fd) { struct index_mm_value *itr, *itr_end; int ch, pushed; pushed = buf_pushchars(buf, node->prefix); itr = node->values.values; itr_end = itr + node->values.len; for (; itr < itr_end; itr++) { write_str_safe(fd, buf->bytes, buf->used); write_str_safe(fd, " ", 1); write_str_safe(fd, itr->value, itr->len); write_str_safe(fd, "\n", 1); } for (ch = node->first; ch <= node->last; ch++) { struct index_mm_node *child = index_mm_readchild(node, ch); if (child == NULL) continue; buf_pushchar(buf, ch); index_mm_dump_node(child, buf, fd); buf_popchar(buf); } buf_popchars(buf, pushed); index_mm_free_node(node); } void index_mm_dump(struct index_mm *idx, int fd, const char *prefix) { struct index_mm_node *root; struct buffer buf; root = index_mm_readroot(idx); if (root == NULL) return; buf_init(&buf); buf_pushchars(&buf, prefix); index_mm_dump_node(root, &buf, fd); buf_release(&buf); } static char *index_mm_search_node(struct index_mm_node *node, const char *key, int i) { char *value; struct index_mm_node *child; int ch; int j; while(node) { for (j = 0; node->prefix[j]; j++) { ch = node->prefix[j]; if (ch != key[i+j]) { index_mm_free_node(node); return NULL; } } i += j; if (key[i] == '\0') { value = node->values.len > 0 ? strdup(node->values.values[0].value) : NULL; index_mm_free_node(node); return value; } child = index_mm_readchild(node, key[i]); index_mm_free_node(node); node = child; i++; } return NULL; } /* * Search the index for a key * * Returns the value of the first match * * The recursive functions free their node argument (using index_close). */ char *index_mm_search(struct index_mm *idx, const char *key) { // FIXME: return value by reference instead of strdup struct index_mm_node *root; char *value; root = index_mm_readroot(idx); value = index_mm_search_node(root, key, 0); return value; } /* Level 4: add all the values from a matching node */ static void index_mm_searchwild_allvalues(struct index_mm_node *node, struct index_value **out) { struct index_mm_value *itr, *itr_end; itr = node->values.values; itr_end = itr + node->values.len; for (; itr < itr_end; itr++) add_value(out, itr->value, itr->len, itr->priority); index_mm_free_node(node); } /* * Level 3: traverse a sub-keyspace which starts with a wildcard, * looking for matches. */ static void index_mm_searchwild_all(struct index_mm_node *node, int j, struct buffer *buf, const char *subkey, struct index_value **out) { int pushed = 0; int ch; while (node->prefix[j]) { ch = node->prefix[j]; buf_pushchar(buf, ch); pushed++; j++; } for (ch = node->first; ch <= node->last; ch++) { struct index_mm_node *child = index_mm_readchild(node, ch); if (!child) continue; buf_pushchar(buf, ch); index_mm_searchwild_all(child, 0, buf, subkey, out); buf_popchar(buf); } if (node->values.len > 0) { if (fnmatch(buf_str(buf), subkey, 0) == 0) index_mm_searchwild_allvalues(node, out); else index_mm_free_node(node); } else { index_mm_free_node(node); } buf_popchars(buf, pushed); } /* Level 2: descend the tree (until we hit a wildcard) */ static void index_mm_searchwild_node(struct index_mm_node *node, struct buffer *buf, const char *key, int i, struct index_value **out) { struct index_mm_node *child; int j; int ch; while(node) { for (j = 0; node->prefix[j]; j++) { ch = node->prefix[j]; if (ch == '*' || ch == '?' || ch == '[') { index_mm_searchwild_all(node, j, buf, &key[i+j], out); return; } if (ch != key[i+j]) { index_mm_free_node(node); return; } } i += j; child = index_mm_readchild(node, '*'); if (child) { buf_pushchar(buf, '*'); index_mm_searchwild_all(child, 0, buf, &key[i], out); buf_popchar(buf); } child = index_mm_readchild(node, '?'); if (child) { buf_pushchar(buf, '?'); index_mm_searchwild_all(child, 0, buf, &key[i], out); buf_popchar(buf); } child = index_mm_readchild(node, '['); if (child) { buf_pushchar(buf, '['); index_mm_searchwild_all(child, 0, buf, &key[i], out); buf_popchar(buf); } if (key[i] == '\0') { index_mm_searchwild_allvalues(node, out); return; } child = index_mm_readchild(node, key[i]); index_mm_free_node(node); node = child; i++; } } /* * Search the index for a key. The index may contain wildcards. * * Returns a list of all the values of matching keys. */ struct index_value *index_mm_searchwild(struct index_mm *idx, const char *key) { struct index_mm_node *root = index_mm_readroot(idx); struct buffer buf; struct index_value *out = NULL; buf_init(&buf); index_mm_searchwild_node(root, &buf, key, 0, &out); buf_release(&buf); return out; }