+++ /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 <systemd/sd-daemon.h>
-
-#include "util.h"
-#include "log.h"
-#include "list.h"
-#include "tcpwrap.h"
-#include "def.h"
-
-#define STREAMS_MAX 4096
-#define SERVER_FD_MAX 16
-#define TIMEOUT_MSEC ((int) (DEFAULT_EXIT_USEC/USEC_PER_MSEC))
-
-typedef struct Stream Stream;
-
-typedef struct Server {
- int syslog_fd;
- int kmsg_fd;
- int epoll_fd;
-
- unsigned n_server_fd;
-
- bool syslog_is_stream;
-
- LIST_HEAD(Stream, streams);
- unsigned n_streams;
-} Server;
-
-typedef enum StreamTarget {
- STREAM_SYSLOG,
- STREAM_KMSG
-} StreamTarget;
-
-typedef enum StreamState {
- STREAM_TARGET,
- STREAM_PRIORITY,
- STREAM_PROCESS,
- STREAM_PREFIX,
- STREAM_RUNNING
-} StreamState;
-
-struct Stream {
- Server *server;
-
- StreamState state;
-
- int fd;
-
- StreamTarget target;
- int priority;
- char *process;
- pid_t pid;
- uid_t uid;
- gid_t gid;
-
- bool prefix:1;
- bool tee_console:1;
-
- char buffer[LINE_MAX+1];
- size_t length;
-
- LIST_FIELDS(Stream, stream);
-};
-
-static int stream_log(Stream *s, char *p, usec_t ts) {
-
- char header_priority[16], header_time[64], header_pid[16];
- struct iovec iovec[5];
- int priority;
-
- assert(s);
- assert(p);
-
- priority = s->priority;
-
- if (s->prefix)
- parse_syslog_priority(&p, &priority);
-
- if (*p == 0)
- return 0;
-
- /* Patch in configured facility if necessary */
- if ((priority & LOG_FACMASK) == 0)
- priority = (s->priority & LOG_FACMASK) | priority;
-
- /*
- * The format glibc uses to talk to the syslog daemon is:
- *
- * <priority>time process[pid]: msg
- *
- * The format the kernel uses is:
- *
- * <priority>msg\n
- *
- * We extend the latter to include the process name and pid.
- */
-
- snprintf(header_priority, sizeof(header_priority), "<%i>", priority);
- char_array_0(header_priority);
-
- if (s->target == STREAM_SYSLOG) {
- time_t t;
- struct tm *tm;
-
- t = (time_t) (ts / USEC_PER_SEC);
- if (!(tm = localtime(&t)))
- return -EINVAL;
-
- if (strftime(header_time, sizeof(header_time), "%h %e %T ", tm) <= 0)
- return -EINVAL;
- }
-
- snprintf(header_pid, sizeof(header_pid), "[%lu]: ", (unsigned long) s->pid);
- char_array_0(header_pid);
-
- zero(iovec);
- IOVEC_SET_STRING(iovec[0], header_priority);
-
- if (s->target == STREAM_SYSLOG) {
- struct msghdr msghdr;
- union {
- struct cmsghdr cmsghdr;
- uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
- } control;
- struct ucred *ucred;
-
- zero(control);
- 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);
- ucred->pid = s->pid;
- ucred->uid = s->uid;
- ucred->gid = s->gid;
-
- IOVEC_SET_STRING(iovec[1], header_time);
- IOVEC_SET_STRING(iovec[2], s->process);
- IOVEC_SET_STRING(iovec[3], header_pid);
- IOVEC_SET_STRING(iovec[4], p);
-
- /* When using syslog via SOCK_STREAM separate the messages by NUL chars */
- if (s->server->syslog_is_stream)
- iovec[4].iov_len++;
-
- zero(msghdr);
- msghdr.msg_iov = iovec;
- msghdr.msg_iovlen = ELEMENTSOF(iovec);
- msghdr.msg_control = &control;
- msghdr.msg_controllen = control.cmsghdr.cmsg_len;
-
- for (;;) {
- ssize_t n;
-
- if ((n = sendmsg(s->server->syslog_fd, &msghdr, MSG_NOSIGNAL)) < 0) {
-
- if (errno == ESRCH) {
- pid_t our_pid;
-
- /* Hmm, maybe the process this
- * line originates from is
- * dead? Then let's patch in
- * our own pid and retry,
- * since we have nothing
- * better */
-
- our_pid = getpid();
-
- if (ucred->pid != our_pid) {
- ucred->pid = our_pid;
- continue;
- }
- }
-
- return -errno;
- }
-
- if (!s->server->syslog_is_stream ||
- (size_t) n >= IOVEC_TOTAL_SIZE(iovec, ELEMENTSOF(iovec)))
- break;
-
- IOVEC_INCREMENT(iovec, ELEMENTSOF(iovec), n);
- }
-
- } else if (s->target == STREAM_KMSG) {
- IOVEC_SET_STRING(iovec[1], s->process);
- IOVEC_SET_STRING(iovec[2], header_pid);
- IOVEC_SET_STRING(iovec[3], p);
- IOVEC_SET_STRING(iovec[4], (char*) "\n");
-
- if (writev(s->server->kmsg_fd, iovec, ELEMENTSOF(iovec)) < 0)
- return -errno;
- } else
- assert_not_reached("Unknown log target");
-
- if (s->tee_console) {
- int console;
-
- if ((console = open_terminal("/dev/console", O_WRONLY|O_NOCTTY|O_CLOEXEC)) >= 0) {
- IOVEC_SET_STRING(iovec[0], s->process);
- IOVEC_SET_STRING(iovec[1], header_pid);
- IOVEC_SET_STRING(iovec[2], p);
- IOVEC_SET_STRING(iovec[3], (char*) "\n");
-
- writev(console, iovec, 4);
- }
- }
-
- return 0;
-}
-
-static int stream_line(Stream *s, char *p, usec_t ts) {
- int r;
-
- assert(s);
- assert(p);
-
- p = strstrip(p);
-
- switch (s->state) {
-
- case STREAM_TARGET:
- if (streq(p, "syslog") || streq(p, "syslog+console"))
- s->target = STREAM_SYSLOG;
- else if (streq(p, "kmsg") || streq(p, "kmsg+console")) {
-
- if (s->server->kmsg_fd >= 0 && s->uid == 0)
- s->target = STREAM_KMSG;
- else {
- log_warning("/dev/kmsg logging not available.");
- return -EPERM;
- }
- } else {
- log_warning("Failed to parse log target line.");
- return -EBADMSG;
- }
-
- if (endswith(p, "+console"))
- s->tee_console = true;
-
- s->state = STREAM_PRIORITY;
- return 0;
-
- case STREAM_PRIORITY:
- if ((r = safe_atoi(p, &s->priority)) < 0) {
- log_warning("Failed to parse log priority line: %m");
- return r;
- }
-
- if (s->priority < 0) {
- log_warning("Log priority negative: %m");
- return -ERANGE;
- }
-
- s->state = STREAM_PROCESS;
- return 0;
-
- case STREAM_PROCESS:
- if (!(s->process = strdup(p)))
- return -ENOMEM;
-
- s->state = STREAM_PREFIX;
- return 0;
-
- case STREAM_PREFIX:
-
- if ((r = parse_boolean(p)) < 0)
- return r;
-
- s->prefix = r;
- s->state = STREAM_RUNNING;
- return 0;
-
- case STREAM_RUNNING:
- return stream_log(s, p, ts);
- }
-
- assert_not_reached("Unknown stream state");
-}
-
-static int stream_scan(Stream *s, usec_t ts) {
- char *p;
- size_t remaining;
- int r = 0;
-
- assert(s);
-
- p = s->buffer;
- remaining = s->length;
- for (;;) {
- char *end;
- size_t skip;
-
- end = memchr(p, '\n', remaining);
- if (!end) {
- if (remaining >= LINE_MAX) {
- end = p + LINE_MAX;
- skip = LINE_MAX;
- } else
- break;
- } else
- skip = end - p + 1;
-
- *end = 0;
-
- r = stream_line(s, p, ts);
- if (r >= 0) {
- remaining -= skip;
- p += skip;
- }
- }
-
- if (p > s->buffer) {
- memmove(s->buffer, p, remaining);
- s->length = remaining;
- }
-
- return r;
-}
-
-static int stream_process(Stream *s, usec_t ts) {
- ssize_t l;
- int r;
- assert(s);
-
- l = read(s->fd, s->buffer+s->length, LINE_MAX-s->length);
- if (l < 0) {
-
- if (errno == EAGAIN)
- return 0;
-
- log_warning("Failed to read from stream: %m");
- return -errno;
- }
-
- if (l == 0)
- return 0;
-
- s->length += l;
- r = stream_scan(s, ts);
-
- if (r < 0)
- return r;
-
- return 1;
-}
-
-static void stream_free(Stream *s) {
- assert(s);
-
- if (s->server) {
- assert(s->server->n_streams > 0);
- s->server->n_streams--;
- LIST_REMOVE(Stream, stream, s->server->streams, s);
-
- }
-
- if (s->fd >= 0) {
- if (s->server)
- epoll_ctl(s->server->epoll_fd, EPOLL_CTL_DEL, s->fd, NULL);
-
- close_nointr_nofail(s->fd);
- }
-
- free(s->process);
- free(s);
-}
-
-static int stream_new(Server *s, int server_fd) {
- Stream *stream;
- int fd;
- struct ucred ucred;
- socklen_t len = sizeof(ucred);
- struct epoll_event ev;
- int r;
-
- assert(s);
- assert(server_fd >= 0);
-
- fd = accept4(server_fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC);
- if (fd < 0)
- return -errno;
-
- if (s->n_streams >= STREAMS_MAX) {
- log_warning("Too many connections, refusing connection.");
- close_nointr_nofail(fd);
- return 0;
- }
-
- if (!socket_tcpwrap(fd, "systemd-stdout-syslog-bridge")) {
- close_nointr_nofail(fd);
- return 0;
- }
-
- if (!(stream = new0(Stream, 1))) {
- close_nointr_nofail(fd);
- return -ENOMEM;
- }
-
- stream->fd = fd;
-
- if (getsockopt(stream->fd, SOL_SOCKET, SO_PEERCRED, &ucred, &len) < 0) {
- r = -errno;
- goto fail;
- }
-
- if (shutdown(fd, SHUT_WR) < 0) {
- r = -errno;
- goto fail;
- }
-
- zero(ev);
- ev.data.ptr = stream;
- ev.events = EPOLLIN;
- if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0) {
- r = -errno;
- goto fail;
- }
-
- stream->pid = ucred.pid;
- stream->uid = ucred.uid;
- stream->gid = ucred.gid;
-
- stream->server = s;
- LIST_PREPEND(Stream, stream, s->streams, stream);
- s->n_streams ++;
-
- return 0;
-
-fail:
- stream_free(stream);
- return r;
-}
-
-static void server_done(Server *s) {
- unsigned i;
- assert(s);
-
- while (s->streams)
- stream_free(s->streams);
-
- for (i = 0; i < s->n_server_fd; i++)
- close_nointr_nofail(SD_LISTEN_FDS_START+i);
-
- if (s->syslog_fd >= 0)
- close_nointr_nofail(s->syslog_fd);
-
- if (s->epoll_fd >= 0)
- close_nointr_nofail(s->epoll_fd);
-
- if (s->kmsg_fd >= 0)
- close_nointr_nofail(s->kmsg_fd);
-}
-
-static int server_init(Server *s, unsigned n_sockets) {
- int r;
- unsigned i;
- union {
- struct sockaddr sa;
- struct sockaddr_un un;
- } sa;
-
- assert(s);
- assert(n_sockets > 0);
-
- zero(*s);
-
- s->n_server_fd = n_sockets;
- s->syslog_fd = -1;
- s->kmsg_fd = -1;
-
- if ((s->epoll_fd = epoll_create1(EPOLL_CLOEXEC)) < 0) {
- r = -errno;
- log_error("Failed to create epoll object: %m");
- goto fail;
- }
-
- for (i = 0; i < n_sockets; i++) {
- struct epoll_event ev;
- int fd;
-
- fd = SD_LISTEN_FDS_START+i;
-
- if ((r = sd_is_socket(fd, AF_UNSPEC, SOCK_STREAM, 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;
- }
-
- /* We use ev.data.ptr instead of ev.data.fd here,
- * since on 64bit archs fd is 32bit while a pointer is
- * 64bit. To make sure we can easily distinguish fd
- * values and pointer values we want to make sure to
- * write the full field unconditionally. */
-
- zero(ev);
- ev.events = EPOLLIN;
- ev.data.ptr = INT_TO_PTR(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: %m");
- goto fail;
- }
- }
-
- zero(sa);
- sa.un.sun_family = AF_UNIX;
- strncpy(sa.un.sun_path, "/dev/log", sizeof(sa.un.sun_path));
-
- if ((s->syslog_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0)) < 0) {
- r = -errno;
- log_error("Failed to create log fd: %m");
- goto fail;
- }
-
- if (connect(s->syslog_fd, &sa.sa, sizeof(sa)) < 0) {
- close_nointr_nofail(s->syslog_fd);
-
- if ((s->syslog_fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0)) < 0) {
- r = -errno;
- log_error("Failed to create log fd: %m");
- goto fail;
- }
-
- if (connect(s->syslog_fd, &sa.sa, sizeof(sa)) < 0) {
- r = -errno;
- log_error("Failed to connect log socket to /dev/log: %m");
- goto fail;
- }
-
- s->syslog_is_stream = true;
- } else
- s->syslog_is_stream = false;
-
- /* /dev/kmsg logging is strictly optional */
- if ((s->kmsg_fd = open("/dev/kmsg", O_WRONLY|O_NOCTTY|O_CLOEXEC)) < 0)
- log_warning("Failed to open /dev/kmsg for logging, disabling kernel log buffer support: %m");
-
- return 0;
-
-fail:
- server_done(s);
- return r;
-}
-
-static int process_event(Server *s, struct epoll_event *ev) {
- int r;
-
- assert(s);
-
- /* Yes, this is a bit ugly, we assume that that valid pointers
- * are > SD_LISTEN_FDS_START+SERVER_FD_MAX. Which is certainly
- * true on Linux (and probably most other OSes, too, since the
- * first 4k usually are part of a separate null pointer
- * dereference page. */
-
- if (PTR_TO_INT(ev->data.ptr) >= SD_LISTEN_FDS_START &&
- PTR_TO_INT(ev->data.ptr) < SD_LISTEN_FDS_START+(int)s->n_server_fd) {
-
- if (ev->events != EPOLLIN) {
- log_info("Got invalid event from epoll. (1)");
- return -EIO;
- }
-
- if ((r = stream_new(s, PTR_TO_INT(ev->data.ptr))) < 0) {
- log_info("Failed to accept new connection: %s", strerror(-r));
- return r;
- }
-
- } else {
- usec_t ts;
- Stream *stream = ev->data.ptr;
-
- ts = now(CLOCK_REALTIME);
-
- if (!(ev->events & EPOLLIN)) {
- log_info("Got invalid event from epoll. (2)");
- stream_free(stream);
- return 0;
- }
-
- if ((r = stream_process(stream, ts)) <= 0) {
-
- if (r < 0)
- log_info("Got error on stream: %s", strerror(-r));
-
- stream_free(stream);
- return 0;
- }
- }
-
- return 0;
-}
-
-int main(int argc, char *argv[]) {
- Server server;
- int r = EXIT_FAILURE, n;
-
- if (getppid() != 1) {
- log_error("This program should be invoked by init only.");
- return EXIT_FAILURE;
- }
-
- if (argc > 1) {
- log_error("This program does not take arguments.");
- return EXIT_FAILURE;
- }
-
- log_set_target(LOG_TARGET_SYSLOG_OR_KMSG);
- log_parse_environment();
- log_open();
-
- umask(0022);
-
- n = sd_listen_fds(true);
- if (n < 0) {
- log_error("Failed to read listening file descriptors from environment: %s", strerror(-r));
- return EXIT_FAILURE;
- }
-
- if (n <= 0 || n > SERVER_FD_MAX) {
- log_error("No or too many file descriptors passed.");
- return EXIT_FAILURE;
- }
-
- if (server_init(&server, (unsigned) n) < 0)
- return EXIT_FAILURE;
-
- log_debug("systemd-stdout-syslog-bridge running as pid %lu", (unsigned long) getpid());
-
- sd_notify(false,
- "READY=1\n"
- "STATUS=Processing requests...");
-
- for (;;) {
- struct epoll_event event;
- int k;
-
- if ((k = epoll_wait(server.epoll_fd,
- &event, 1,
- server.n_streams <= 0 ? TIMEOUT_MSEC : -1)) < 0) {
-
- if (errno == EINTR)
- continue;
-
- log_error("epoll_wait() failed: %m");
- goto fail;
- }
-
- if (k <= 0)
- break;
-
- if (process_event(&server, &event) < 0)
- goto fail;
- }
-
- r = EXIT_SUCCESS;
-
- log_debug("systemd-stdout-syslog-bridge stopped as pid %lu", (unsigned long) getpid());
-
-fail:
- sd_notify(false,
- "STATUS=Shutting down...");
-
- server_done(&server);
-
- return r;
-}
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