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/***
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 "basic/alloc-util.h"
#include "basic/fd-util.h"
#include "basic/fs-util.h"
#include "basic/parse-util.h"
#include "basic/path-util.h"
#include "basic/socket-util.h"
#include "basic/strv.h"
#include "basic/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 htobe16(port) == sockaddr.in.sin_port;
} else {
if (l < sizeof(struct sockaddr_in6))
return -EINVAL;
return htobe16(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;
}
|