journald: splitt of syslog protocol support into its own file

1 files changed, 358 insertions, 0 deletions

diff --git a/src/journal/journald-syslog.c b/src/journal/journald-syslog.c
new file mode 100644
index 0000000000..91664762e6
--- /dev/null
+++ b/src/journal/journald-syslog.c
@@ -0,0 +1,358 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2011 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 <unistd.h>
+#include <sys/epoll.h>
+
+#include "socket-util.h"
+#include "journald.h"
+#include "journald-syslog.h"
+#include "journald-kmsg.h"
+
+static void forward_syslog_iovec(Server *s, const struct iovec *iovec, unsigned n_iovec, struct ucred *ucred, struct timeval *tv) {
+        struct msghdr msghdr;
+        struct cmsghdr *cmsg;
+        union {
+                struct cmsghdr cmsghdr;
+                uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
+        } control;
+        union sockaddr_union sa;
+
+        assert(s);
+        assert(iovec);
+        assert(n_iovec > 0);
+
+        zero(msghdr);
+        msghdr.msg_iov = (struct iovec*) iovec;
+        msghdr.msg_iovlen = n_iovec;
+
+        zero(sa);
+        sa.un.sun_family = AF_UNIX;
+        strncpy(sa.un.sun_path, "/run/systemd/journal/syslog", sizeof(sa.un.sun_path));
+        msghdr.msg_name = &sa;
+        msghdr.msg_namelen = offsetof(union sockaddr_union, un.sun_path) + strlen(sa.un.sun_path);
+
+        if (ucred) {
+                zero(control);
+                msghdr.msg_control = &control;
+                msghdr.msg_controllen = sizeof(control);
+
+                cmsg = CMSG_FIRSTHDR(&msghdr);
+                cmsg->cmsg_level = SOL_SOCKET;
+                cmsg->cmsg_type = SCM_CREDENTIALS;
+                cmsg->cmsg_len = CMSG_LEN(sizeof(struct ucred));
+                memcpy(CMSG_DATA(cmsg), ucred, sizeof(struct ucred));
+                msghdr.msg_controllen = cmsg->cmsg_len;
+        }
+
+        /* Forward the syslog message we received via /dev/log to
+         * /run/systemd/syslog. Unfortunately we currently can't set
+         * the SO_TIMESTAMP auxiliary data, and hence we don't. */
+
+        if (sendmsg(s->syslog_fd, &msghdr, MSG_NOSIGNAL) >= 0)
+                return;
+
+        /* The socket is full? I guess the syslog implementation is
+         * too slow, and we shouldn't wait for that... */
+        if (errno == EAGAIN)
+                return;
+
+        if (ucred && errno == ESRCH) {
+                struct ucred u;
+
+                /* Hmm, presumably the sender process vanished
+                 * by now, so let's fix it as good as we
+                 * can, and retry */
+
+                u = *ucred;
+                u.pid = getpid();
+                memcpy(CMSG_DATA(cmsg), &u, sizeof(struct ucred));
+
+                if (sendmsg(s->syslog_fd, &msghdr, MSG_NOSIGNAL) >= 0)
+                        return;
+
+                if (errno == EAGAIN)
+                        return;
+        }
+
+        if (errno != ENOENT)
+                log_debug("Failed to forward syslog message: %m");
+}
+
+static void forward_syslog_raw(Server *s, int priority, const char *buffer, struct ucred *ucred, struct timeval *tv) {
+        struct iovec iovec;
+
+        assert(s);
+        assert(buffer);
+
+        if (LOG_PRI(priority) > s->max_level_syslog)
+                return;
+
+        IOVEC_SET_STRING(iovec, buffer);
+        forward_syslog_iovec(s, &iovec, 1, ucred, tv);
+}
+
+void server_forward_syslog(Server *s, int priority, const char *identifier, const char *message, struct ucred *ucred, struct timeval *tv) {
+        struct iovec iovec[5];
+        char header_priority[6], header_time[64], header_pid[16];
+        int n = 0;
+        time_t t;
+        struct tm *tm;
+        char *ident_buf = NULL;
+
+        assert(s);
+        assert(priority >= 0);
+        assert(priority <= 999);
+        assert(message);
+
+        if (LOG_PRI(priority) > s->max_level_syslog)
+                return;
+
+        /* First: priority field */
+        snprintf(header_priority, sizeof(header_priority), "<%i>", priority);
+        char_array_0(header_priority);
+        IOVEC_SET_STRING(iovec[n++], header_priority);
+
+        /* Second: timestamp */
+        t = tv ? tv->tv_sec : ((time_t) (now(CLOCK_REALTIME) / USEC_PER_SEC));
+        tm = localtime(&t);
+        if (!tm)
+                return;
+        if (strftime(header_time, sizeof(header_time), "%h %e %T ", tm) <= 0)
+                return;
+        IOVEC_SET_STRING(iovec[n++], header_time);
+
+        /* Third: identifier and PID */
+        if (ucred) {
+                if (!identifier) {
+                        get_process_comm(ucred->pid, &ident_buf);
+                        identifier = ident_buf;
+                }
+
+                snprintf(header_pid, sizeof(header_pid), "[%lu]: ", (unsigned long) ucred->pid);
+                char_array_0(header_pid);
+
+                if (identifier)
+                        IOVEC_SET_STRING(iovec[n++], identifier);
+
+                IOVEC_SET_STRING(iovec[n++], header_pid);
+        } else if (identifier) {
+                IOVEC_SET_STRING(iovec[n++], identifier);
+                IOVEC_SET_STRING(iovec[n++], ": ");
+        }
+
+        /* Fourth: message */
+        IOVEC_SET_STRING(iovec[n++], message);
+
+        forward_syslog_iovec(s, iovec, n, ucred, tv);
+
+        free(ident_buf);
+}
+
+int syslog_fixup_facility(int priority) {
+
+        if ((priority & LOG_FACMASK) == 0)
+                return (priority & LOG_PRIMASK) | LOG_USER;
+
+        return priority;
+}
+
+void syslog_read_identifier(const char **buf, char **identifier, char **pid) {
+        const char *p;
+        char *t;
+        size_t l, e;
+
+        assert(buf);
+        assert(identifier);
+        assert(pid);
+
+        p = *buf;
+
+        p += strspn(p, WHITESPACE);
+        l = strcspn(p, WHITESPACE);
+
+        if (l <= 0 ||
+            p[l-1] != ':')
+                return;
+
+        e = l;
+        l--;
+
+        if (p[l-1] == ']') {
+                size_t k = l-1;
+
+                for (;;) {
+
+                        if (p[k] == '[') {
+                                t = strndup(p+k+1, l-k-2);
+                                if (t)
+                                        *pid = t;
+
+                                l = k;
+                                break;
+                        }
+
+                        if (k == 0)
+                                break;
+
+                        k--;
+                }
+        }
+
+        t = strndup(p, l);
+        if (t)
+                *identifier = t;
+
+        *buf = p + e;
+        *buf += strspn(*buf, WHITESPACE);
+}
+
+void server_process_syslog_message(
+        Server *s,
+        const char *buf,
+        struct ucred *ucred,
+        struct timeval *tv,
+        const char *label,
+        size_t label_len) {
+
+        char *message = NULL, *syslog_priority = NULL, *syslog_facility = NULL, *syslog_identifier = NULL, *syslog_pid = NULL;
+        struct iovec iovec[N_IOVEC_META_FIELDS + 6];
+        unsigned n = 0;
+        int priority = LOG_USER | LOG_INFO;
+        char *identifier = NULL, *pid = NULL;
+        const char *orig;
+
+        assert(s);
+        assert(buf);
+
+        orig = buf;
+        syslog_parse_priority((char**) &buf, &priority);
+
+        if (s->forward_to_syslog)
+                forward_syslog_raw(s, priority, orig, ucred, tv);
+
+        syslog_skip_date((char**) &buf);
+        syslog_read_identifier(&buf, &identifier, &pid);
+
+        if (s->forward_to_kmsg)
+                server_forward_kmsg(s, priority, identifier, buf, ucred);
+
+        if (s->forward_to_console)
+                server_forward_console(s, priority, identifier, buf, ucred);
+
+        IOVEC_SET_STRING(iovec[n++], "_TRANSPORT=syslog");
+
+        if (asprintf(&syslog_priority, "PRIORITY=%i", priority & LOG_PRIMASK) >= 0)
+                IOVEC_SET_STRING(iovec[n++], syslog_priority);
+
+        if (priority & LOG_FACMASK)
+                if (asprintf(&syslog_facility, "SYSLOG_FACILITY=%i", LOG_FAC(priority)) >= 0)
+                        IOVEC_SET_STRING(iovec[n++], syslog_facility);
+
+        if (identifier) {
+                syslog_identifier = strappend("SYSLOG_IDENTIFIER=", identifier);
+                if (syslog_identifier)
+                        IOVEC_SET_STRING(iovec[n++], syslog_identifier);
+        }
+
+        if (pid) {
+                syslog_pid = strappend("SYSLOG_PID=", pid);
+                if (syslog_pid)
+                        IOVEC_SET_STRING(iovec[n++], syslog_pid);
+        }
+
+        message = strappend("MESSAGE=", buf);
+        if (message)
+                IOVEC_SET_STRING(iovec[n++], message);
+
+        server_dispatch_message(s, iovec, n, ELEMENTSOF(iovec), ucred, tv, label, label_len, NULL, priority);
+
+        free(message);
+        free(identifier);
+        free(pid);
+        free(syslog_priority);
+        free(syslog_facility);
+        free(syslog_identifier);
+        free(syslog_pid);
+}
+
+int server_open_syslog_socket(Server *s) {
+        union sockaddr_union sa;
+        int one, r;
+        struct epoll_event ev;
+
+        assert(s);
+
+        if (s->syslog_fd < 0) {
+
+                s->syslog_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
+                if (s->syslog_fd < 0) {
+                        log_error("socket() failed: %m");
+                        return -errno;
+                }
+
+                zero(sa);
+                sa.un.sun_family = AF_UNIX;
+                strncpy(sa.un.sun_path, "/dev/log", sizeof(sa.un.sun_path));
+
+                unlink(sa.un.sun_path);
+
+                r = bind(s->syslog_fd, &sa.sa, offsetof(union sockaddr_union, un.sun_path) + strlen(sa.un.sun_path));
+                if (r < 0) {
+                        log_error("bind() failed: %m");
+                        return -errno;
+                }
+
+                chmod(sa.un.sun_path, 0666);
+        } else
+                fd_nonblock(s->syslog_fd, 1);
+
+        one = 1;
+        r = setsockopt(s->syslog_fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one));
+        if (r < 0) {
+                log_error("SO_PASSCRED failed: %m");
+                return -errno;
+        }
+
+#ifdef HAVE_SELINUX
+        one = 1;
+        r = setsockopt(s->syslog_fd, SOL_SOCKET, SO_PASSSEC, &one, sizeof(one));
+        if (r < 0)
+                log_warning("SO_PASSSEC failed: %m");
+#endif
+
+        one = 1;
+        r = setsockopt(s->syslog_fd, SOL_SOCKET, SO_TIMESTAMP, &one, sizeof(one));
+        if (r < 0) {
+                log_error("SO_TIMESTAMP failed: %m");
+                return -errno;
+        }
+
+        zero(ev);
+        ev.events = EPOLLIN;
+        ev.data.fd = s->syslog_fd;
+        if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, s->syslog_fd, &ev) < 0) {
+                log_error("Failed to add syslog server fd to epoll object: %m");
+                return -errno;
+        }
+
+        return 0;
+}