diff options
Diffstat (limited to 'src/libsystemd/src/sd-daemon/sd-daemon.c')
-rw-r--r-- | src/libsystemd/src/sd-daemon/sd-daemon.c | 622 |
1 files changed, 622 insertions, 0 deletions
diff --git a/src/libsystemd/src/sd-daemon/sd-daemon.c b/src/libsystemd/src/sd-daemon/sd-daemon.c new file mode 100644 index 0000000000..fa92199c43 --- /dev/null +++ b/src/libsystemd/src/sd-daemon/sd-daemon.c @@ -0,0 +1,622 @@ +/*** + This file is part of systemd. + + Copyright 2010 Lennart Poettering + + systemd 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. + + systemd 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 systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <errno.h> +#include <limits.h> +#include <mqueue.h> +#include <netinet/in.h> +#include <stdarg.h> +#include <stddef.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/socket.h> +#include <sys/stat.h> +#include <sys/un.h> +#include <unistd.h> + +#include <systemd/sd-daemon.h> + +#include "alloc-util.h" +#include "fd-util.h" +#include "fs-util.h" +#include "parse-util.h" +#include "path-util.h" +#include "socket-util.h" +#include "strv.h" +#include "util.h" + +#define SNDBUF_SIZE (8*1024*1024) + +static void unsetenv_all(bool unset_environment) { + + if (!unset_environment) + return; + + unsetenv("LISTEN_PID"); + unsetenv("LISTEN_FDS"); + unsetenv("LISTEN_FDNAMES"); +} + +_public_ int sd_listen_fds(int unset_environment) { + const char *e; + int n, r, fd; + pid_t pid; + + e = getenv("LISTEN_PID"); + if (!e) { + r = 0; + goto finish; + } + + r = parse_pid(e, &pid); + if (r < 0) + goto finish; + + /* Is this for us? */ + if (getpid() != pid) { + r = 0; + goto finish; + } + + e = getenv("LISTEN_FDS"); + if (!e) { + r = 0; + goto finish; + } + + r = safe_atoi(e, &n); + if (r < 0) + goto finish; + + assert_cc(SD_LISTEN_FDS_START < INT_MAX); + if (n <= 0 || n > INT_MAX - SD_LISTEN_FDS_START) { + r = -EINVAL; + goto finish; + } + + for (fd = SD_LISTEN_FDS_START; fd < SD_LISTEN_FDS_START + n; fd ++) { + r = fd_cloexec(fd, true); + if (r < 0) + goto finish; + } + + r = n; + +finish: + unsetenv_all(unset_environment); + return r; +} + +_public_ int sd_listen_fds_with_names(int unset_environment, char ***names) { + _cleanup_strv_free_ char **l = NULL; + bool have_names; + int n_names = 0, n_fds; + const char *e; + int r; + + if (!names) + return sd_listen_fds(unset_environment); + + e = getenv("LISTEN_FDNAMES"); + if (e) { + n_names = strv_split_extract(&l, e, ":", EXTRACT_DONT_COALESCE_SEPARATORS); + if (n_names < 0) { + unsetenv_all(unset_environment); + return n_names; + } + + have_names = true; + } else + have_names = false; + + n_fds = sd_listen_fds(unset_environment); + if (n_fds <= 0) + return n_fds; + + if (have_names) { + if (n_names != n_fds) + return -EINVAL; + } else { + r = strv_extend_n(&l, "unknown", n_fds); + if (r < 0) + return r; + } + + *names = l; + l = NULL; + + return n_fds; +} + +_public_ int sd_is_fifo(int fd, const char *path) { + struct stat st_fd; + + assert_return(fd >= 0, -EBADF); + + if (fstat(fd, &st_fd) < 0) + return -errno; + + if (!S_ISFIFO(st_fd.st_mode)) + return 0; + + if (path) { + struct stat st_path; + + if (stat(path, &st_path) < 0) { + + if (errno == ENOENT || errno == ENOTDIR) + return 0; + + return -errno; + } + + return + st_path.st_dev == st_fd.st_dev && + st_path.st_ino == st_fd.st_ino; + } + + return 1; +} + +_public_ int sd_is_special(int fd, const char *path) { + struct stat st_fd; + + assert_return(fd >= 0, -EBADF); + + if (fstat(fd, &st_fd) < 0) + return -errno; + + if (!S_ISREG(st_fd.st_mode) && !S_ISCHR(st_fd.st_mode)) + return 0; + + if (path) { + struct stat st_path; + + if (stat(path, &st_path) < 0) { + + if (errno == ENOENT || errno == ENOTDIR) + return 0; + + return -errno; + } + + if (S_ISREG(st_fd.st_mode) && S_ISREG(st_path.st_mode)) + return + st_path.st_dev == st_fd.st_dev && + st_path.st_ino == st_fd.st_ino; + else if (S_ISCHR(st_fd.st_mode) && S_ISCHR(st_path.st_mode)) + return st_path.st_rdev == st_fd.st_rdev; + else + return 0; + } + + return 1; +} + +static int sd_is_socket_internal(int fd, int type, int listening) { + struct stat st_fd; + + assert_return(fd >= 0, -EBADF); + assert_return(type >= 0, -EINVAL); + + if (fstat(fd, &st_fd) < 0) + return -errno; + + if (!S_ISSOCK(st_fd.st_mode)) + return 0; + + if (type != 0) { + int other_type = 0; + socklen_t l = sizeof(other_type); + + if (getsockopt(fd, SOL_SOCKET, SO_TYPE, &other_type, &l) < 0) + return -errno; + + if (l != sizeof(other_type)) + return -EINVAL; + + if (other_type != type) + return 0; + } + + if (listening >= 0) { + int accepting = 0; + socklen_t l = sizeof(accepting); + + if (getsockopt(fd, SOL_SOCKET, SO_ACCEPTCONN, &accepting, &l) < 0) + return -errno; + + if (l != sizeof(accepting)) + return -EINVAL; + + if (!accepting != !listening) + return 0; + } + + return 1; +} + +_public_ int sd_is_socket(int fd, int family, int type, int listening) { + int r; + + assert_return(fd >= 0, -EBADF); + assert_return(family >= 0, -EINVAL); + + r = sd_is_socket_internal(fd, type, listening); + if (r <= 0) + return r; + + if (family > 0) { + union sockaddr_union sockaddr = {}; + socklen_t l = sizeof(sockaddr); + + if (getsockname(fd, &sockaddr.sa, &l) < 0) + return -errno; + + if (l < sizeof(sa_family_t)) + return -EINVAL; + + return sockaddr.sa.sa_family == family; + } + + return 1; +} + +_public_ int sd_is_socket_inet(int fd, int family, int type, int listening, uint16_t port) { + union sockaddr_union sockaddr = {}; + socklen_t l = sizeof(sockaddr); + int r; + + assert_return(fd >= 0, -EBADF); + assert_return(IN_SET(family, 0, AF_INET, AF_INET6), -EINVAL); + + r = sd_is_socket_internal(fd, type, listening); + if (r <= 0) + return r; + + if (getsockname(fd, &sockaddr.sa, &l) < 0) + return -errno; + + if (l < sizeof(sa_family_t)) + return -EINVAL; + + if (sockaddr.sa.sa_family != AF_INET && + sockaddr.sa.sa_family != AF_INET6) + return 0; + + if (family != 0) + if (sockaddr.sa.sa_family != family) + return 0; + + if (port > 0) { + if (sockaddr.sa.sa_family == AF_INET) { + if (l < sizeof(struct sockaddr_in)) + return -EINVAL; + + return htons(port) == sockaddr.in.sin_port; + } else { + if (l < sizeof(struct sockaddr_in6)) + return -EINVAL; + + return htons(port) == sockaddr.in6.sin6_port; + } + } + + return 1; +} + +_public_ int sd_is_socket_unix(int fd, int type, int listening, const char *path, size_t length) { + union sockaddr_union sockaddr = {}; + socklen_t l = sizeof(sockaddr); + int r; + + assert_return(fd >= 0, -EBADF); + + r = sd_is_socket_internal(fd, type, listening); + if (r <= 0) + return r; + + if (getsockname(fd, &sockaddr.sa, &l) < 0) + return -errno; + + if (l < sizeof(sa_family_t)) + return -EINVAL; + + if (sockaddr.sa.sa_family != AF_UNIX) + return 0; + + if (path) { + if (length == 0) + length = strlen(path); + + if (length == 0) + /* Unnamed socket */ + return l == offsetof(struct sockaddr_un, sun_path); + + if (path[0]) + /* Normal path socket */ + return + (l >= offsetof(struct sockaddr_un, sun_path) + length + 1) && + memcmp(path, sockaddr.un.sun_path, length+1) == 0; + else + /* Abstract namespace socket */ + return + (l == offsetof(struct sockaddr_un, sun_path) + length) && + memcmp(path, sockaddr.un.sun_path, length) == 0; + } + + return 1; +} + +_public_ int sd_is_mq(int fd, const char *path) { + struct mq_attr attr; + + /* Check that the fd is valid */ + assert_return(fcntl(fd, F_GETFD) >= 0, -errno); + + if (mq_getattr(fd, &attr) < 0) { + if (errno == EBADF) + /* A non-mq fd (or an invalid one, but we ruled that out above) */ + return 0; + return -errno; + } + + if (path) { + char fpath[PATH_MAX]; + struct stat a, b; + + assert_return(path_is_absolute(path), -EINVAL); + + if (fstat(fd, &a) < 0) + return -errno; + + strncpy(stpcpy(fpath, "/dev/mqueue"), path, sizeof(fpath) - 12); + fpath[sizeof(fpath)-1] = 0; + + if (stat(fpath, &b) < 0) + return -errno; + + if (a.st_dev != b.st_dev || + a.st_ino != b.st_ino) + return 0; + } + + return 1; +} + +_public_ int sd_pid_notify_with_fds(pid_t pid, int unset_environment, const char *state, const int *fds, unsigned n_fds) { + union sockaddr_union sockaddr = { + .sa.sa_family = AF_UNIX, + }; + struct iovec iovec = { + .iov_base = (char*) state, + }; + struct msghdr msghdr = { + .msg_iov = &iovec, + .msg_iovlen = 1, + .msg_name = &sockaddr, + }; + _cleanup_close_ int fd = -1; + struct cmsghdr *cmsg = NULL; + const char *e; + bool have_pid; + int r; + + if (!state) { + r = -EINVAL; + goto finish; + } + + if (n_fds > 0 && !fds) { + r = -EINVAL; + goto finish; + } + + e = getenv("NOTIFY_SOCKET"); + if (!e) + return 0; + + /* Must be an abstract socket, or an absolute path */ + if ((e[0] != '@' && e[0] != '/') || e[1] == 0) { + r = -EINVAL; + goto finish; + } + + if (strlen(e) > sizeof(sockaddr.un.sun_path)) { + r = -EINVAL; + goto finish; + } + + fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0); + if (fd < 0) { + r = -errno; + goto finish; + } + + fd_inc_sndbuf(fd, SNDBUF_SIZE); + + iovec.iov_len = strlen(state); + + strncpy(sockaddr.un.sun_path, e, sizeof(sockaddr.un.sun_path)); + if (sockaddr.un.sun_path[0] == '@') + sockaddr.un.sun_path[0] = 0; + + msghdr.msg_namelen = SOCKADDR_UN_LEN(sockaddr.un); + + have_pid = pid != 0 && pid != getpid(); + + if (n_fds > 0 || have_pid) { + /* CMSG_SPACE(0) may return value different than zero, which results in miscalculated controllen. */ + msghdr.msg_controllen = + (n_fds > 0 ? CMSG_SPACE(sizeof(int) * n_fds) : 0) + + (have_pid ? CMSG_SPACE(sizeof(struct ucred)) : 0); + + msghdr.msg_control = alloca0(msghdr.msg_controllen); + + cmsg = CMSG_FIRSTHDR(&msghdr); + if (n_fds > 0) { + cmsg->cmsg_level = SOL_SOCKET; + cmsg->cmsg_type = SCM_RIGHTS; + cmsg->cmsg_len = CMSG_LEN(sizeof(int) * n_fds); + + memcpy(CMSG_DATA(cmsg), fds, sizeof(int) * n_fds); + + if (have_pid) + assert_se(cmsg = CMSG_NXTHDR(&msghdr, cmsg)); + } + + if (have_pid) { + struct ucred *ucred; + + cmsg->cmsg_level = SOL_SOCKET; + cmsg->cmsg_type = SCM_CREDENTIALS; + cmsg->cmsg_len = CMSG_LEN(sizeof(struct ucred)); + + ucred = (struct ucred*) CMSG_DATA(cmsg); + ucred->pid = pid; + ucred->uid = getuid(); + ucred->gid = getgid(); + } + } + + /* First try with fake ucred data, as requested */ + if (sendmsg(fd, &msghdr, MSG_NOSIGNAL) >= 0) { + r = 1; + goto finish; + } + + /* If that failed, try with our own ucred instead */ + if (have_pid) { + msghdr.msg_controllen -= CMSG_SPACE(sizeof(struct ucred)); + if (msghdr.msg_controllen == 0) + msghdr.msg_control = NULL; + + if (sendmsg(fd, &msghdr, MSG_NOSIGNAL) >= 0) { + r = 1; + goto finish; + } + } + + r = -errno; + +finish: + if (unset_environment) + unsetenv("NOTIFY_SOCKET"); + + return r; +} + +_public_ int sd_pid_notify(pid_t pid, int unset_environment, const char *state) { + return sd_pid_notify_with_fds(pid, unset_environment, state, NULL, 0); +} + +_public_ int sd_notify(int unset_environment, const char *state) { + return sd_pid_notify_with_fds(0, unset_environment, state, NULL, 0); +} + +_public_ int sd_pid_notifyf(pid_t pid, int unset_environment, const char *format, ...) { + _cleanup_free_ char *p = NULL; + int r; + + if (format) { + va_list ap; + + va_start(ap, format); + r = vasprintf(&p, format, ap); + va_end(ap); + + if (r < 0 || !p) + return -ENOMEM; + } + + return sd_pid_notify(pid, unset_environment, p); +} + +_public_ int sd_notifyf(int unset_environment, const char *format, ...) { + _cleanup_free_ char *p = NULL; + int r; + + if (format) { + va_list ap; + + va_start(ap, format); + r = vasprintf(&p, format, ap); + va_end(ap); + + if (r < 0 || !p) + return -ENOMEM; + } + + return sd_pid_notify(0, unset_environment, p); +} + +_public_ int sd_booted(void) { + /* We test whether the runtime unit file directory has been + * created. This takes place in mount-setup.c, so is + * guaranteed to happen very early during boot. */ + + return laccess("/run/systemd/system/", F_OK) >= 0; +} + +_public_ int sd_watchdog_enabled(int unset_environment, uint64_t *usec) { + const char *s, *p = ""; /* p is set to dummy value to do unsetting */ + uint64_t u; + int r = 0; + + s = getenv("WATCHDOG_USEC"); + if (!s) + goto finish; + + r = safe_atou64(s, &u); + if (r < 0) + goto finish; + if (u <= 0 || u >= USEC_INFINITY) { + r = -EINVAL; + goto finish; + } + + p = getenv("WATCHDOG_PID"); + if (p) { + pid_t pid; + + r = parse_pid(p, &pid); + if (r < 0) + goto finish; + + /* Is this for us? */ + if (getpid() != pid) { + r = 0; + goto finish; + } + } + + if (usec) + *usec = u; + + r = 1; + +finish: + if (unset_environment && s) + unsetenv("WATCHDOG_USEC"); + if (unset_environment && p) + unsetenv("WATCHDOG_PID"); + + return r; +} |