From 3ee897d6c2401effbc82f5eef35fce405781d6c8 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Wed, 23 Sep 2015 01:00:04 +0200 Subject: tree-wide: port more code to use send_one_fd() and receive_one_fd() Also, make it slightly more powerful, by accepting a flags argument, and make it safe for handling if more than one cmsg attribute happens to be attached. --- src/basic/util.c | 84 ++++++++++------------------------- src/basic/util.h | 4 +- src/core/namespace.c | 44 +++++------------- src/import/importd.c | 8 ++-- src/journal/journal-send.c | 26 +---------- src/libsystemd/sd-bus/bus-container.c | 11 +---- src/nspawn/nspawn-expose-ports.c | 4 +- src/nspawn/nspawn.c | 2 +- 8 files changed, 47 insertions(+), 136 deletions(-) (limited to 'src') diff --git a/src/basic/util.c b/src/basic/util.c index bc61ec0115..c788a1d58b 100644 --- a/src/basic/util.c +++ b/src/basic/util.c @@ -6201,15 +6201,6 @@ int ptsname_malloc(int fd, char **ret) { int openpt_in_namespace(pid_t pid, int flags) { _cleanup_close_ int pidnsfd = -1, mntnsfd = -1, usernsfd = -1, rootfd = -1; _cleanup_close_pair_ int pair[2] = { -1, -1 }; - union { - struct cmsghdr cmsghdr; - uint8_t buf[CMSG_SPACE(sizeof(int))]; - } control = {}; - struct msghdr mh = { - .msg_control = &control, - .msg_controllen = sizeof(control), - }; - struct cmsghdr *cmsg; siginfo_t si; pid_t child; int r; @@ -6243,15 +6234,7 @@ int openpt_in_namespace(pid_t pid, int flags) { if (unlockpt(master) < 0) _exit(EXIT_FAILURE); - cmsg = CMSG_FIRSTHDR(&mh); - cmsg->cmsg_level = SOL_SOCKET; - cmsg->cmsg_type = SCM_RIGHTS; - cmsg->cmsg_len = CMSG_LEN(sizeof(int)); - memcpy(CMSG_DATA(cmsg), &master, sizeof(int)); - - mh.msg_controllen = cmsg->cmsg_len; - - if (sendmsg(pair[1], &mh, MSG_NOSIGNAL) < 0) + if (send_one_fd(pair[1], master, 0) < 0) _exit(EXIT_FAILURE); _exit(EXIT_SUCCESS); @@ -6265,26 +6248,7 @@ int openpt_in_namespace(pid_t pid, int flags) { if (si.si_code != CLD_EXITED || si.si_status != EXIT_SUCCESS) return -EIO; - if (recvmsg(pair[0], &mh, MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) < 0) - return -errno; - - CMSG_FOREACH(cmsg, &mh) - if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) { - int *fds; - unsigned n_fds; - - fds = (int*) CMSG_DATA(cmsg); - n_fds = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int); - - if (n_fds != 1) { - close_many(fds, n_fds); - return -EIO; - } - - return fds[0]; - } - - return -EIO; + return receive_one_fd(pair[0], 0); } ssize_t fgetxattrat_fake(int dirfd, const char *filename, const char *attribute, void *value, size_t size, int flags) { @@ -6884,7 +6848,7 @@ int fgetxattr_malloc(int fd, const char *name, char **value) { } } -int send_one_fd(int transport_fd, int fd) { +int send_one_fd(int transport_fd, int fd, int flags) { union { struct cmsghdr cmsghdr; uint8_t buf[CMSG_SPACE(sizeof(int))]; @@ -6894,7 +6858,6 @@ int send_one_fd(int transport_fd, int fd) { .msg_controllen = sizeof(control), }; struct cmsghdr *cmsg; - ssize_t k; assert(transport_fd >= 0); assert(fd >= 0); @@ -6906,14 +6869,13 @@ int send_one_fd(int transport_fd, int fd) { memcpy(CMSG_DATA(cmsg), &fd, sizeof(int)); mh.msg_controllen = CMSG_SPACE(sizeof(int)); - k = sendmsg(transport_fd, &mh, MSG_NOSIGNAL); - if (k < 0) + if (sendmsg(transport_fd, &mh, MSG_NOSIGNAL | flags) < 0) return -errno; return 0; } -int receive_one_fd(int transport_fd) { +int receive_one_fd(int transport_fd, int flags) { union { struct cmsghdr cmsghdr; uint8_t buf[CMSG_SPACE(sizeof(int))]; @@ -6922,33 +6884,35 @@ int receive_one_fd(int transport_fd) { .msg_control = &control, .msg_controllen = sizeof(control), }; - struct cmsghdr *cmsg; - ssize_t k; + struct cmsghdr *cmsg, *found = NULL; assert(transport_fd >= 0); /* - * Receive a single FD via @transport_fd. We don't care for the - * transport-type, but the caller must assure that no other CMSG types - * than SCM_RIGHTS is enabled. We also retrieve a single FD at most, so - * for packet-based transports, the caller must ensure to send only a - * single FD per packet. - * This is best used in combination with send_one_fd(). + * Receive a single FD via @transport_fd. We don't care for + * the transport-type. We retrieve a single FD at most, so for + * packet-based transports, the caller must ensure to send + * only a single FD per packet. This is best used in + * combination with send_one_fd(). */ - k = recvmsg(transport_fd, &mh, MSG_NOSIGNAL | MSG_CMSG_CLOEXEC); - if (k < 0) + if (recvmsg(transport_fd, &mh, MSG_NOSIGNAL | MSG_CMSG_CLOEXEC | flags) < 0) return -errno; - cmsg = CMSG_FIRSTHDR(&mh); - if (!cmsg || CMSG_NXTHDR(&mh, cmsg) || - cmsg->cmsg_level != SOL_SOCKET || - cmsg->cmsg_type != SCM_RIGHTS || - cmsg->cmsg_len != CMSG_LEN(sizeof(int)) || - *(const int *)CMSG_DATA(cmsg) < 0) { + CMSG_FOREACH(cmsg, &mh) { + if (cmsg->cmsg_level == SOL_SOCKET && + cmsg->cmsg_type == SCM_RIGHTS && + cmsg->cmsg_len == CMSG_LEN(sizeof(int))) { + assert(!found); + found = cmsg; + break; + } + } + + if (!found) { cmsg_close_all(&mh); return -EIO; } - return *(const int *)CMSG_DATA(cmsg); + return *(int*) CMSG_DATA(found); } diff --git a/src/basic/util.h b/src/basic/util.h index 56d9f037bf..e6417b4ccd 100644 --- a/src/basic/util.h +++ b/src/basic/util.h @@ -942,5 +942,5 @@ int reset_uid_gid(void); int getxattr_malloc(const char *path, const char *name, char **value, bool allow_symlink); int fgetxattr_malloc(int fd, const char *name, char **value); -int send_one_fd(int transport_fd, int fd); -int receive_one_fd(int transport_fd); +int send_one_fd(int transport_fd, int fd, int flags); +int receive_one_fd(int transport_fd, int flags); diff --git a/src/core/namespace.c b/src/core/namespace.c index eb88574f8f..2b8b707df5 100644 --- a/src/core/namespace.c +++ b/src/core/namespace.c @@ -643,16 +643,7 @@ int setup_tmp_dirs(const char *id, char **tmp_dir, char **var_tmp_dir) { int setup_netns(int netns_storage_socket[2]) { _cleanup_close_ int netns = -1; - union { - struct cmsghdr cmsghdr; - uint8_t buf[CMSG_SPACE(sizeof(int))]; - } control = {}; - struct msghdr mh = { - .msg_control = &control, - .msg_controllen = sizeof(control), - }; - struct cmsghdr *cmsg; - int r; + int r, q; assert(netns_storage_socket); assert(netns_storage_socket[0] >= 0); @@ -669,12 +660,8 @@ int setup_netns(int netns_storage_socket[2]) { if (lockf(netns_storage_socket[0], F_LOCK, 0) < 0) return -errno; - if (recvmsg(netns_storage_socket[0], &mh, MSG_DONTWAIT|MSG_CMSG_CLOEXEC) < 0) { - if (errno != EAGAIN) { - r = -errno; - goto fail; - } - + netns = receive_one_fd(netns_storage_socket[0], MSG_DONTWAIT); + if (netns == -EAGAIN) { /* Nothing stored yet, so let's create a new namespace */ if (unshare(CLONE_NEWNET) < 0) { @@ -691,15 +678,13 @@ int setup_netns(int netns_storage_socket[2]) { } r = 1; - } else { - /* Yay, found something, so let's join the namespace */ - CMSG_FOREACH(cmsg, &mh) - if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) { - assert(cmsg->cmsg_len == CMSG_LEN(sizeof(int))); - netns = *(int*) CMSG_DATA(cmsg); - } + } else if (netns < 0) { + r = netns; + goto fail; + } else { + /* Yay, found something, so let's join the namespace */ if (setns(netns, CLONE_NEWNET) < 0) { r = -errno; goto fail; @@ -708,21 +693,14 @@ int setup_netns(int netns_storage_socket[2]) { r = 0; } - cmsg = CMSG_FIRSTHDR(&mh); - cmsg->cmsg_level = SOL_SOCKET; - cmsg->cmsg_type = SCM_RIGHTS; - cmsg->cmsg_len = CMSG_LEN(sizeof(int)); - memcpy(CMSG_DATA(cmsg), &netns, sizeof(int)); - mh.msg_controllen = cmsg->cmsg_len; - - if (sendmsg(netns_storage_socket[1], &mh, MSG_DONTWAIT|MSG_NOSIGNAL) < 0) { - r = -errno; + q = send_one_fd(netns_storage_socket[1], netns, MSG_DONTWAIT); + if (q < 0) { + r = q; goto fail; } fail: lockf(netns_storage_socket[0], F_ULOCK, 0); - return r; } diff --git a/src/import/importd.c b/src/import/importd.c index c90ada5da4..a29e9d4bd5 100644 --- a/src/import/importd.c +++ b/src/import/importd.c @@ -600,11 +600,11 @@ static int manager_on_notify(sd_event_source *s, int fd, uint32_t revents, void cmsg_close_all(&msghdr); - CMSG_FOREACH(cmsg, &msghdr) { - if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_CREDENTIALS && cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) - + CMSG_FOREACH(cmsg, &msghdr) + if (cmsg->cmsg_level == SOL_SOCKET && + cmsg->cmsg_type == SCM_CREDENTIALS && + cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) ucred = (struct ucred*) CMSG_DATA(cmsg); - } if (msghdr.msg_flags & MSG_TRUNC) { log_warning("Got overly long notification datagram, ignoring."); diff --git a/src/journal/journal-send.c b/src/journal/journal-send.c index 1e3a463504..dc1b2105dd 100644 --- a/src/journal/journal-send.c +++ b/src/journal/journal-send.c @@ -212,11 +212,6 @@ _public_ int sd_journal_sendv(const struct iovec *iov, int n) { .msg_namelen = offsetof(struct sockaddr_un, sun_path) + strlen(sa.sun_path), }; ssize_t k; - union { - struct cmsghdr cmsghdr; - uint8_t buf[CMSG_SPACE(sizeof(int))]; - } control; - struct cmsghdr *cmsg; bool have_syslog_identifier = false; bool seal = true; @@ -335,26 +330,7 @@ _public_ int sd_journal_sendv(const struct iovec *iov, int n) { return r; } - mh.msg_iov = NULL; - mh.msg_iovlen = 0; - - zero(control); - mh.msg_control = &control; - mh.msg_controllen = sizeof(control); - - cmsg = CMSG_FIRSTHDR(&mh); - cmsg->cmsg_level = SOL_SOCKET; - cmsg->cmsg_type = SCM_RIGHTS; - cmsg->cmsg_len = CMSG_LEN(sizeof(int)); - memcpy(CMSG_DATA(cmsg), &buffer_fd, sizeof(int)); - - mh.msg_controllen = cmsg->cmsg_len; - - k = sendmsg(fd, &mh, MSG_NOSIGNAL); - if (k < 0) - return -errno; - - return 0; + return send_one_fd(fd, buffer_fd, 0); } static int fill_iovec_perror_and_send(const char *message, int skip, struct iovec iov[]) { diff --git a/src/libsystemd/sd-bus/bus-container.c b/src/libsystemd/sd-bus/bus-container.c index 5c607f49b1..435ec92d6f 100644 --- a/src/libsystemd/sd-bus/bus-container.c +++ b/src/libsystemd/sd-bus/bus-container.c @@ -217,15 +217,8 @@ int bus_container_connect_kernel(sd_bus *b) { _exit(EXIT_FAILURE); } - cmsg = CMSG_FIRSTHDR(&mh); - cmsg->cmsg_level = SOL_SOCKET; - cmsg->cmsg_type = SCM_RIGHTS; - cmsg->cmsg_len = CMSG_LEN(sizeof(int)); - memcpy(CMSG_DATA(cmsg), &fd, sizeof(int)); - - mh.msg_controllen = cmsg->cmsg_len; - - if (sendmsg(pair[1], &mh, MSG_NOSIGNAL) < 0) + r = send_one_fd(pair[1], fd, 0); + if (r < 0) _exit(EXIT_FAILURE); _exit(EXIT_SUCCESS); diff --git a/src/nspawn/nspawn-expose-ports.c b/src/nspawn/nspawn-expose-ports.c index 9e63d88b69..3658f45381 100644 --- a/src/nspawn/nspawn-expose-ports.c +++ b/src/nspawn/nspawn-expose-ports.c @@ -194,7 +194,7 @@ int expose_port_send_rtnl(int send_fd) { /* Store away the fd in the socket, so that it stays open as * long as we run the child */ - r = send_one_fd(send_fd, fd); + r = send_one_fd(send_fd, fd, 0); if (r < 0) return log_error_errno(r, "Failed to send netlink fd: %m"); @@ -214,7 +214,7 @@ int expose_port_watch_rtnl( assert(recv_fd >= 0); assert(ret); - fd = receive_one_fd(recv_fd); + fd = receive_one_fd(recv_fd, 0); if (fd < 0) return log_error_errno(fd, "Failed to recv netlink fd: %m"); diff --git a/src/nspawn/nspawn.c b/src/nspawn/nspawn.c index 7451c2bf64..f4721a1c29 100644 --- a/src/nspawn/nspawn.c +++ b/src/nspawn/nspawn.c @@ -1291,7 +1291,7 @@ static int setup_kmsg(const char *dest, int kmsg_socket) { /* Store away the fd in the socket, so that it stays open as * long as we run the child */ - r = send_one_fd(kmsg_socket, fd); + r = send_one_fd(kmsg_socket, fd, 0); safe_close(fd); if (r < 0) -- cgit v1.2.1