--- /dev/null
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+ 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 General Public License as published by
+ the Free Software Foundation; either version 2 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
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <assert.h>
+#include <time.h>
+#include <string.h>
+#include <stdio.h>
+#include <errno.h>
+#include <unistd.h>
+#include <sys/poll.h>
+#include <sys/epoll.h>
+#include <sys/un.h>
+#include <fcntl.h>
+#include <sys/signalfd.h>
+
+#include "util.h"
+#include "log.h"
+#include "sd-daemon.h"
+#include "fdset.h"
+
+#define SERVER_FD_MAX 16
+#define TIMEOUT ((int) (10*MSEC_PER_SEC))
+
+typedef struct Stream Stream;
+
+typedef struct Server {
+ FDSet *syslog_fds;
+ int kmsg_fd;
+ int epoll_fd;
+ int signal_fd;
+} Server;
+
+static void server_done(Server *s) {
+ assert(s);
+
+ if (s->epoll_fd >= 0)
+ close_nointr_nofail(s->epoll_fd);
+
+ if (s->kmsg_fd >= 0)
+ close_nointr_nofail(s->kmsg_fd);
+
+ if (s->signal_fd >= 0)
+ close_nointr_nofail(s->signal_fd);
+
+ if (s->syslog_fds)
+ fdset_free(s->syslog_fds);
+}
+
+static int server_init(Server *s, unsigned n_sockets) {
+ int r;
+ unsigned i;
+ struct epoll_event ev;
+ sigset_t mask;
+
+ assert(s);
+ assert(n_sockets > 0);
+
+ zero(*s);
+
+ s->kmsg_fd = s->signal_fd = -1;
+
+ if ((s->epoll_fd = epoll_create1(EPOLL_CLOEXEC)) < 0) {
+ r = -errno;
+ log_error("Failed to create epoll object: %s", strerror(errno));
+ goto fail;
+ }
+
+ if (!(s->syslog_fds = fdset_new())) {
+ r = -ENOMEM;
+ log_error("Failed to allocate file descriptor set: %s", strerror(errno));
+ goto fail;
+ }
+
+ for (i = 0; i < n_sockets; i++) {
+ int fd, one = 1;
+
+ fd = SD_LISTEN_FDS_START+i;
+
+ if ((r = sd_is_socket(fd, AF_UNSPEC, SOCK_DGRAM, -1)) < 0) {
+ log_error("Failed to determine file descriptor type: %s", strerror(-r));
+ goto fail;
+ }
+
+ if (!r) {
+ log_error("Wrong file descriptor type.");
+ r = -EINVAL;
+ goto fail;
+ }
+
+ if (setsockopt(fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one)) < 0)
+ log_error("SO_PASSCRED failed: %m");
+
+ zero(ev);
+ ev.events = EPOLLIN;
+ ev.data.fd = fd;
+ if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0) {
+ r = -errno;
+ log_error("Failed to add server fd to epoll object: %s", strerror(errno));
+ goto fail;
+ }
+
+ if ((r = fdset_put(s->syslog_fds, fd)) < 0) {
+ log_error("Failed to store file descriptor in set: %s", strerror(-r));
+ goto fail;
+ }
+ }
+
+ if ((s->kmsg_fd = open("/dev/kmsg", O_WRONLY|O_NOCTTY|O_CLOEXEC)) < 0) {
+ log_error("Failed to open /dev/kmsg for logging: %m");
+ return -errno;
+ }
+
+ assert_se(sigemptyset(&mask) == 0);
+ sigset_add_many(&mask, SIGINT, SIGTERM, -1);
+ assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
+
+ if ((s->signal_fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC)) < 0) {
+ log_error("signalfd(): %m");
+ return -errno;
+ }
+
+ zero(ev);
+ ev.events = EPOLLIN;
+ ev.data.fd = s->signal_fd;
+
+ if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, s->signal_fd, &ev) < 0) {
+ log_error("epoll_ctl(): %m");
+ return -errno;
+ }
+
+ return 0;
+
+fail:
+ server_done(s);
+ return r;
+}
+
+static int read_priority(const char **buf) {
+ int priority;
+ size_t n;
+ const char *p;
+ int a, b, c;
+
+ assert(buf);
+ assert(*buf);
+
+ p = *buf;
+ n = strlen(p);
+
+ if (n < 3 || p[0] != '<')
+ goto fail;
+
+ if (p[2] == '>') {
+ a = b = 0;
+ c = undecchar(p[1]);
+ p += 3;
+ } else if (n >= 4 && p[3] == '>') {
+ a = 0;
+ b = undecchar(p[1]);
+ c = undecchar(p[2]);
+ p += 4;
+ } else if (n >= 5 && p[4] == '>') {
+ a = undecchar(p[1]);
+ b = undecchar(p[2]);
+ c = undecchar(p[3]);
+ p += 5;
+ } else
+ goto fail;
+
+ if (a < 0 || b < 0 || c < 0)
+ goto fail;
+
+ *buf = p;
+
+ priority = 100*a + 10*b + c;
+ return LOG_PRI(priority);
+
+fail:
+ return LOG_INFO;
+}
+
+static void skip_date(const char **buf) {
+ enum {
+ LETTER,
+ SPACE,
+ NUMBER,
+ SPACE_OR_NUMBER,
+ COLON
+ } sequence[] = {
+ LETTER, LETTER, LETTER,
+ SPACE,
+ SPACE_OR_NUMBER, NUMBER,
+ SPACE,
+ SPACE_OR_NUMBER, NUMBER,
+ COLON,
+ SPACE_OR_NUMBER, NUMBER,
+ COLON,
+ SPACE_OR_NUMBER, NUMBER,
+ SPACE
+ };
+
+ const char *p;
+ unsigned i;
+
+ assert(buf);
+ assert(*buf);
+
+ p = *buf;
+
+ for (i = 0; i < ELEMENTSOF(sequence); i++, p++) {
+
+ if (!*p)
+ return;
+
+ switch (sequence[i]) {
+
+ case SPACE:
+ if (*p != ' ')
+ return;
+ break;
+
+ case SPACE_OR_NUMBER:
+ if (*p == ' ')
+ break;
+
+ /* fall through */
+
+ case NUMBER:
+ if (*p < '0' || *p > '9')
+ return;
+
+ break;
+
+ case LETTER:
+ if (!(*p >= 'A' && *p <= 'Z') &&
+ !(*p >= 'a' && *p <= 'z'))
+ return;
+
+ break;
+
+ case COLON:
+ if (*p != ':')
+ return;
+ break;
+
+ }
+ }
+
+ *buf = p;
+}
+
+static int read_process(const char **buf, struct iovec *iovec) {
+ const char *p;
+ size_t l;
+
+ assert(buf);
+ assert(*buf);
+ assert(iovec);
+
+ p = *buf;
+
+ p += strspn(p, WHITESPACE);
+ l = strcspn(p, WHITESPACE);
+
+ if (l <= 0 ||
+ p[l-1] != ':')
+ return 0;
+
+ l--;
+
+ if (p[l-1] == ']') {
+ size_t k = l-1;
+
+ for (;;) {
+
+ if (p[k] == '[') {
+ l = k;
+ break;
+ }
+
+ if (k == 0)
+ break;
+
+ k--;
+ }
+ }
+
+ iovec->iov_base = (char*) p;
+ iovec->iov_len = l;
+ *buf = p + l;
+ return 1;
+}
+
+static void skip_pid(const char **buf) {
+ const char *p;
+
+ assert(buf);
+ assert(*buf);
+
+ p = *buf;
+
+ if (*p != '[')
+ return;
+
+ p++;
+ p += strspn(p, "0123456789");
+
+ if (*p != ']')
+ return;
+
+ p++;
+
+ *buf = p;
+}
+
+static int write_message(Server *s, const char *buf, struct ucred *ucred) {
+ ssize_t k;
+ char priority[4], pid[16];
+ struct iovec iovec[5];
+ unsigned i = 0;
+ char *process = NULL;
+ int r = 0;
+
+ assert(s);
+ assert(buf);
+
+ /* First, set priority field */
+ snprintf(priority, sizeof(priority), "<%i>", read_priority(&buf));
+ char_array_0(priority);
+ IOVEC_SET_STRING(iovec[i++], priority);
+
+ /* Second, skip date */
+ skip_date(&buf);
+
+ /* Then, add process if set */
+ if (read_process(&buf, &iovec[i]) > 0)
+ i++;
+ else if (ucred && get_process_name(ucred->pid, &process) >= 0)
+ IOVEC_SET_STRING(iovec[i++], process);
+
+ /* Skip the stored PID if we have a better one */
+ if (ucred) {
+ snprintf(pid, sizeof(pid), "[%lu]: ", (unsigned long) ucred->pid);
+ char_array_0(pid);
+ IOVEC_SET_STRING(iovec[i++], pid);
+
+ skip_pid(&buf);
+
+ if (*buf == ':')
+ buf++;
+
+ buf += strspn(buf, WHITESPACE);
+ }
+
+ /* Is the remaining message empty? */
+ if (*buf) {
+
+ /* And the rest is the message */
+ IOVEC_SET_STRING(iovec[i++], buf);
+ IOVEC_SET_STRING(iovec[i++], "\n");
+
+ if ((k = writev(s->kmsg_fd, iovec, i)) <= 0) {
+ log_error("Failed to write log message to kmsg: %s", k < 0 ? strerror(errno) : "short write");
+ r = k < 0 ? -errno : -EIO;
+ }
+ }
+
+ free(process);
+
+ return r;
+}
+
+static int process_event(Server *s, struct epoll_event *ev) {
+ assert(s);
+
+ if (ev->events != EPOLLIN) {
+ log_info("Got invalid event from epoll.");
+ return -EIO;
+ }
+
+ if (ev->data.fd == s->signal_fd) {
+ struct signalfd_siginfo sfsi;
+ ssize_t n;
+
+ if ((n = read(s->signal_fd, &sfsi, sizeof(sfsi))) != sizeof(sfsi)) {
+
+ if (n >= 0)
+ return -EIO;
+
+ if (errno == EINTR || errno == EAGAIN)
+ return 0;
+
+ return -errno;
+ }
+
+ log_debug("Received SIG%s", strna(signal_to_string(sfsi.ssi_signo)));
+ return 0;
+
+ } else {
+ for (;;) {
+ char buf[LINE_MAX+1];
+ struct msghdr msghdr;
+ struct iovec iovec;
+ struct ucred *ucred;
+ union {
+ struct cmsghdr cmsghdr;
+ uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
+ } control;
+ ssize_t n;
+ int k;
+ char *e;
+
+ zero(iovec);
+ iovec.iov_base = buf;
+ iovec.iov_len = sizeof(buf)-1;
+
+ zero(control);
+ zero(msghdr);
+ msghdr.msg_iov = &iovec;
+ msghdr.msg_iovlen = 1;
+ msghdr.msg_control = &control;
+ msghdr.msg_controllen = sizeof(control);
+
+ if ((n = recvmsg(ev->data.fd, &msghdr, MSG_DONTWAIT)) < 0) {
+
+ if (errno == EINTR || errno == EAGAIN)
+ return 1;
+
+ log_error("recvmsg() failed: %m");
+ return -errno;
+ }
+
+ if (msghdr.msg_controllen >= CMSG_LEN(sizeof(struct ucred)) &&
+ control.cmsghdr.cmsg_level == SOL_SOCKET &&
+ control.cmsghdr.cmsg_type == SCM_CREDENTIALS &&
+ control.cmsghdr.cmsg_len == CMSG_LEN(sizeof(struct ucred)))
+ ucred = (struct ucred*) CMSG_DATA(&control.cmsghdr);
+ else
+ ucred = NULL;
+
+ if ((e = memchr(buf, '\n', n)))
+ *e = 0;
+ else
+ buf[n] = 0;
+
+ if ((k = write_message(s, strstrip(buf), ucred)) < 0)
+ return k;
+ }
+ }
+
+ return 1;
+}
+
+int main(int argc, char *argv[]) {
+ Server server;
+ int r = 3, n;
+
+ if (getppid() != 1) {
+ log_error("This program should be invoked by init only.");
+ return 1;
+ }
+
+ if (argc > 1) {
+ log_error("This program does not take arguments.");
+ return 1;
+ }
+
+ log_set_target(LOG_TARGET_KMSG);
+ log_parse_environment();
+ log_open();
+
+ if ((n = sd_listen_fds(true)) < 0) {
+ log_error("Failed to read listening file descriptors from environment: %s", strerror(-r));
+ return 1;
+ }
+
+ if (n <= 0 || n > SERVER_FD_MAX) {
+ log_error("No or too many file descriptors passed.");
+ return 2;
+ }
+
+ if (server_init(&server, (unsigned) n) < 0)
+ return 3;
+
+ log_debug("systemd-kmsg-syslogd running as pid %lu", (unsigned long) getpid());
+
+ sd_notify(false,
+ "READY=1\n"
+ "STATUS=Processing messages...");
+
+ for (;;) {
+ struct epoll_event event;
+ int k;
+
+ if ((k = epoll_wait(server.epoll_fd, &event, 1, TIMEOUT)) < 0) {
+
+ if (errno == EINTR)
+ continue;
+
+ log_error("epoll_wait() failed: %m");
+ goto fail;
+ }
+
+ if (k <= 0)
+ break;
+
+ if ((k = process_event(&server, &event)) < 0)
+ goto fail;
+
+ if (k == 0)
+ break;
+ }
+
+ r = 0;
+
+ log_debug("systemd-kmsg-syslogd stopped as pid %lu", (unsigned long) getpid());
+
+fail:
+ sd_notify(false,
+ "STATUS=Shutting down...");
+
+ server_done(&server);
+
+ return r;
+}
projects / systemd / commitdiff