[systemd-devel] [PATCH] journald: Introduce RFC 5424 syslog

Umut Tezduyar Lindskog umut at tezduyar.com
Thu Feb 19 00:23:42 PST 2015


Hi Susant,

On Thu, Feb 19, 2015 at 8:58 AM, Susant Sahani <susant at redhat.com> wrote:
> This patch adds support for RFC 5424 syslog format to journald. Journald
> can now forward logs to a multicast UDP group.
>
> RFC 5424 format:
> <PRI>VERSION SP TIMESTAMP SP HOSTNAME SP APP-NAME SP PROCID SP MSGID SP
> [SD-ID]s SP MSG
>
> Example conf:
>
> file: journald.conf
> SysLogAddress=239.0.0.1:6000
> ---
>  Makefile.am                           |   1 +
>  man/journald.conf.xml                 |  12 ++
>  src/journal/journald-gperf.gperf      |   1 +
>  src/journal/journald-native.c         |   3 +
>  src/journal/journald-server.c         |  40 +++++-
>  src/journal/journald-server.h         |  14 ++
>  src/journal/journald-stream.c         |   4 +
>  src/journal/journald-syslog-network.c | 246 ++++++++++++++++++++++++++++++++++
>  src/journal/journald-syslog.c         |   3 +
>  src/journal/journald-syslog.h         |   2 +
>  10 files changed, 325 insertions(+), 1 deletion(-)
>  create mode 100644 src/journal/journald-syslog-network.c
>
> diff --git a/Makefile.am b/Makefile.am
> index ba63f68..b015f69 100644
> --- a/Makefile.am
> +++ b/Makefile.am
> @@ -4487,6 +4487,7 @@ libsystemd_journal_core_la_SOURCES = \
>         src/journal/journald-kmsg.h \
>         src/journal/journald-syslog.c \
>         src/journal/journald-syslog.h \
> +       src/journal/journald-syslog-network.c \
>         src/journal/journald-stream.c \
>         src/journal/journald-stream.h \
>         src/journal/journald-server.c \
> diff --git a/man/journald.conf.xml b/man/journald.conf.xml
> index 364b58f..4fb037b 100644
> --- a/man/journald.conf.xml
> +++ b/man/journald.conf.xml
> @@ -355,6 +355,18 @@
>        </varlistentry>
>
>        <varlistentry>
> +        <term><varname>SysLogAddress=</varname></term>
> +        <listitem><para>Controls whether log messages received by the
> +        journal daemon shall be forwarded to a multicast UDP network
> +        group in syslog RFC 5424 format.</para>
> +
> +        <para>The the address string format is similar to socket units. See
Double "the".
> +        <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>1</manvolnum></citerefentry>
> +        </para>
> +        </listitem>
> +      </varlistentry>
> +
> +      <varlistentry>
>          <term><varname>TTYPath=</varname></term>
>
>          <listitem><para>Change the console TTY to use if
> diff --git a/src/journal/journald-gperf.gperf b/src/journal/journald-gperf.gperf
> index 74554c1..9cdffbc 100644
> --- a/src/journal/journald-gperf.gperf
> +++ b/src/journal/journald-gperf.gperf
> @@ -40,3 +40,4 @@ Journal.MaxLevelKMsg,       config_parse_log_level,  0, offsetof(Server, max_lev
>  Journal.MaxLevelConsole,    config_parse_log_level,  0, offsetof(Server, max_level_console)
>  Journal.MaxLevelWall,       config_parse_log_level,  0, offsetof(Server, max_level_wall)
>  Journal.SplitMode,          config_parse_split_mode, 0, offsetof(Server, split_mode)
> +Journal.SysLogAddress,      config_parse_syslog_network_address, 0, offsetof(Server, syslog_addr)
> diff --git a/src/journal/journald-native.c b/src/journal/journald-native.c
> index 851625d..9fd370f 100644
> --- a/src/journal/journald-native.c
> +++ b/src/journal/journald-native.c
> @@ -273,6 +273,9 @@ void server_process_native_message(
>                  if (s->forward_to_syslog)
>                          server_forward_syslog(s, priority, identifier, message, ucred, tv);
>
> +                if (s->forward_to_network)
> +                        server_forward_syslog_network(s, priority, identifier, message, ucred, tv);
> +
>                  if (s->forward_to_kmsg)
>                          server_forward_kmsg(s, priority, identifier, message, ucred);
>
> diff --git a/src/journal/journald-server.c b/src/journal/journald-server.c
> index 7ee8174..de4ef50 100644
> --- a/src/journal/journald-server.c
> +++ b/src/journal/journald-server.c
> @@ -86,7 +86,7 @@ static const char* const split_mode_table[_SPLIT_MAX] = {
>  DEFINE_STRING_TABLE_LOOKUP(split_mode, SplitMode);
>  DEFINE_CONFIG_PARSE_ENUM(config_parse_split_mode, split_mode, SplitMode, "Failed to parse split mode setting");
>
> -static uint64_t available_space(Server *s, bool verbose) {
> +uint64_t available_space(Server *s, bool verbose) {
>          char ids[33];
>          _cleanup_free_ char *p = NULL;
>          sd_id128_t machine;
> @@ -1356,6 +1356,35 @@ static int server_parse_config_file(Server *s) {
>                                   false, s);
>  }
>
> +int config_parse_syslog_network_address(const char *unit,
> +                                        const char *filename,
> +                                        unsigned line,
> +                                        const char *section,
> +                                        unsigned section_line,
> +                                        const char *lvalue,
> +                                        int ltype,
> +                                        const char *rvalue,
> +                                        void *data,
> +                                        void *userdata) {
> +        Server *s = userdata;
> +        int r;
> +
> +        assert(filename);
> +        assert(lvalue);
> +        assert(rvalue);
> +        assert(data);
> +
> +        r = socket_address_parse(&s->syslog_addr, rvalue);
> +        if (r < 0) {
> +                log_syntax(unit, LOG_ERR, filename, line, -r,
> +                           "Failed to parse address value, ignoring: %s", rvalue);
> +                return 0;
> +        }
> +
> +        s->forward_to_network = true;
> +        return 0;
> +}
> +
>  static int server_dispatch_sync(sd_event_source *es, usec_t t, void *userdata) {
>          Server *s = userdata;
>
> @@ -1578,6 +1607,10 @@ int server_init(Server *s) {
>          if (r < 0)
>                  return r;
>
> +        r = server_open_syslog_network_socket(s);
What happens if forwarding is not enabled?
> +        if (r < 0)
> +                log_error_errno(r, "Failed to open syslog network socket. Ignoring: %m.");
> +
>          r = server_open_native_socket(s);
>          if (r < 0)
>                  return r;
> @@ -1673,6 +1706,7 @@ void server_done(Server *s) {
>          sd_event_unref(s->event);
>
>          safe_close(s->syslog_fd);
> +        safe_close(s->syslog_network_fd);
>          safe_close(s->native_fd);
>          safe_close(s->stdout_fd);
>          safe_close(s->dev_kmsg_fd);
> @@ -1682,6 +1716,9 @@ void server_done(Server *s) {
>          if (s->rate_limit)
>                  journal_rate_limit_free(s->rate_limit);
>
> +        if (s->syslog_network_rate_limit)
> +                journal_rate_limit_free(s->syslog_network_rate_limit);
> +
>          if (s->kernel_seqnum)
>                  munmap(s->kernel_seqnum, sizeof(uint64_t));
>
> @@ -1689,6 +1726,7 @@ void server_done(Server *s) {
>          free(s->tty_path);
>          free(s->cgroup_root);
>          free(s->hostname_field);
> +        free(s->hostname);
>
>          if (s->mmap)
>                  mmap_cache_unref(s->mmap);
> diff --git a/src/journal/journald-server.h b/src/journal/journald-server.h
> index c96877c..ba9e456 100644
> --- a/src/journal/journald-server.h
> +++ b/src/journal/journald-server.h
> @@ -27,6 +27,7 @@
>  #include <sys/types.h>
>  #include <sys/socket.h>
>
> +#include "socket-util.h"
>  #include "sd-event.h"
>  #include "journal-file.h"
>  #include "hashmap.h"
> @@ -56,6 +57,7 @@ typedef struct StdoutStream StdoutStream;
>
>  typedef struct Server {
>          int syslog_fd;
> +        int syslog_network_fd;
>          int native_fd;
>          int stdout_fd;
>          int dev_kmsg_fd;
> @@ -86,6 +88,8 @@ typedef struct Server {
>          size_t buffer_size;
>
>          JournalRateLimit *rate_limit;
> +        JournalRateLimit *syslog_network_rate_limit;
> +
>          usec_t sync_interval_usec;
>          usec_t rate_limit_interval;
>          unsigned rate_limit_burst;
> @@ -98,12 +102,15 @@ typedef struct Server {
>
>          bool forward_to_kmsg;
>          bool forward_to_syslog;
> +        bool forward_to_network;
>          bool forward_to_console;
>          bool forward_to_wall;
>
>          unsigned n_forward_syslog_missed;
>          usec_t last_warn_forward_syslog_missed;
>
> +        unsigned n_forward_syslog_network_missed;
> +
>          uint64_t cached_available_space;
>          usec_t cached_available_space_timestamp;
>
> @@ -140,6 +147,9 @@ typedef struct Server {
>          char machine_id_field[sizeof("_MACHINE_ID=") + 32];
>          char boot_id_field[sizeof("_BOOT_ID=") + 32];
>          char *hostname_field;
> +        char *hostname;
> +
> +        SocketAddress syslog_addr;
>
>          /* Cached cgroup root, so that we don't have to query that all the time */
>          char *cgroup_root;
> @@ -166,13 +176,17 @@ int config_parse_split_mode(const char *unit, const char *filename, unsigned lin
>  const char *split_mode_to_string(SplitMode s) _const_;
>  SplitMode split_mode_from_string(const char *s) _pure_;
>
> +int config_parse_syslog_network_address(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue,void *data, void *userdata);
> +
>  void server_fix_perms(Server *s, JournalFile *f, uid_t uid);
>  int server_init(Server *s);
>  void server_done(Server *s);
>  void server_sync(Server *s);
>  void server_vacuum(Server *s);
>  void server_rotate(Server *s);
> +uint64_t available_space(Server *s, bool verbose);
>  int server_schedule_sync(Server *s, int priority);
>  int server_flush_to_var(Server *s);
>  void server_maybe_append_tags(Server *s);
>  int server_process_datagram(sd_event_source *es, int fd, uint32_t revents, void *userdata);
> +int server_open_syslog_network_socket(Server *s);
> diff --git a/src/journal/journald-stream.c b/src/journal/journald-stream.c
> index 942a857..ccc10a3 100644
> --- a/src/journal/journald-stream.c
> +++ b/src/journal/journald-stream.c
> @@ -69,6 +69,7 @@ struct StdoutStream {
>          int priority;
>          bool level_prefix:1;
>          bool forward_to_syslog:1;
> +        bool forward_to_network:1;
>          bool forward_to_kmsg:1;
>          bool forward_to_console:1;
>
> @@ -243,6 +244,9 @@ static int stdout_stream_log(StdoutStream *s, const char *p) {
>          if (s->forward_to_syslog || s->server->forward_to_syslog)
>                  server_forward_syslog(s->server, syslog_fixup_facility(priority), s->identifier, p, &s->ucred, NULL);
>
> +        if (s->forward_to_network || s->server->forward_to_network)
> +                server_forward_syslog_network(s->server, syslog_fixup_facility(priority), s->identifier, p, &s->ucred, NULL);
> +
>          if (s->forward_to_kmsg || s->server->forward_to_kmsg)
>                  server_forward_kmsg(s->server, priority, s->identifier, p, &s->ucred);
>
> diff --git a/src/journal/journald-syslog-network.c b/src/journal/journald-syslog-network.c
> new file mode 100644
> index 0000000..0f7b494
> --- /dev/null
> +++ b/src/journal/journald-syslog-network.c
> @@ -0,0 +1,246 @@
> +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
> +
> +/***
> +  This file is part of systemd.
> +
> +  Copyright 2015 Susant Sahani
> +
> +  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 <stddef.h>
> +#include <poll.h>
> +
> +#include "shared/in-addr-util.h"
> +#include "journald-server.h"
> +#include "journald-syslog.h"
> +#include "systemd/sd-messages.h"
> +
> +/* Warn once every 30s if we missed syslog message */
> +#define WARN_FORWARD_SYSLOG_MISSED_ID "syslog-network-missed"
> +
> +#define RFC_5424_NILVALUE "-"
> +#define RFC_5424_PROTOCOL 1
> +
> +static void server_maybe_warn_forward_syslog_network_missed(Server *s, int priority) {
> +        int r;
> +
> +        assert(s);
> +
> +        if (s->n_forward_syslog_network_missed <= 0)
> +                return;
> +
> +        r = journal_rate_limit_test(s->syslog_network_rate_limit, WARN_FORWARD_SYSLOG_MISSED_ID,
> +                                    priority & LOG_PRIMASK, available_space(s, false));
> +        if (r == 0)
> +                return;
> +
> +        server_driver_message(s, SD_MESSAGE_FORWARD_SYSLOG_MISSED,
> +                              "Forwarding to syslog network missed %u messages.",
> +                              s->n_forward_syslog_network_missed);
> +
> +        s->n_forward_syslog_network_missed = 0;
> +}
> +
> +static int syslog_network_send(Server *s, struct iovec *iovec, unsigned n_iovec, int priority) {
> +        struct msghdr mh = { };
> +
> +        assert(s);
> +        assert(iovec);
> +        assert(n_iovec > 0);
> +
> +        mh.msg_iov = iovec;
> +        mh.msg_iovlen = n_iovec;
> +
> +        if (s->syslog_addr.sockaddr.sa.sa_family == AF_INET) {
> +                mh.msg_name = &s->syslog_addr.sockaddr.sa;
> +                mh.msg_namelen = sizeof(s->syslog_addr.sockaddr.sa);
> +        } else if (s->syslog_addr.sockaddr.sa.sa_family == AF_INET6) {
> +                mh.msg_name = &s->syslog_addr.sockaddr.in6;
> +                mh.msg_namelen = sizeof(s->syslog_addr.sockaddr.in6);
> +        } else
> +                return -EAFNOSUPPORT;
> +
> +        if (sendmsg(s->syslog_network_fd, &mh, MSG_NOSIGNAL) >= 0)
> +                return 0;
> +
> +        s->n_forward_syslog_network_missed++;
When can forwarding fail that we are keeping track of it? In the end
we just broadcast messages on UDP.
> +
> +        server_maybe_warn_forward_syslog_network_missed(s, priority);
> +
> +        return 0;
> +}
> +
> +/* RFC3339 timestamp format: YYYY-MM-DDTHH:MM:SS[.frac]<+/->ZZ:ZZ */
> +void format_rfc3339_timestamp(const struct timeval *tv, char *header_time, size_t header_size) {
> +        char gm_buf[sizeof("+0530") + 1];
> +        struct tm tm;
> +        time_t t;
> +
> +        t = tv ? tv->tv_sec : ((time_t) (now(CLOCK_REALTIME) / USEC_PER_SEC));
> +        localtime_r(&t, &tm);
> +
> +        strftime(header_time, header_size, "%Y-%m-%dT%T", &tm);
> +
> +        /* add fractional part */
> +        if (tv)
> +                snprintf(header_time + strlen(header_time), header_size, ".%06ld", tv->tv_usec);
> +
> +        /* format the timezone according to RFC */
> +        xstrftime(gm_buf, "%z", &tm);
> +        snprintf(header_time + strlen(header_time), header_size, "%.3s:%.2s ", gm_buf, gm_buf + 3);
> +}
> +
> +/* The Syslog Protocol RFC5424 format :
> + * <PRI>VERSION SP TIMESTAMP SP HOSTNAME SP APP-NAME SP PROCID SP MSGID SP [SD-ID]s SP MSG
> + */
> +void server_forward_syslog_network(Server *s,
> +                                   int priority,
> +                                   const char *identifier,
> +                                   const char *message,
> +                                   const struct ucred *ucred,
> +                                   const struct timeval *tv) {
> +        char header_pid[DECIMAL_STR_MAX(pid_t) + 1];
> +        char header_priority[sizeof("< >1 ") + 1];
> +        char header_time[FORMAT_TIMESTAMP_MAX];
> +        struct iovec iov[13];
> +        int n = 0;
> +
> +        assert(s);
> +        assert(priority >= 0);
> +        assert(priority <= 999);
> +        assert(message);
> +
> +        if (LOG_PRI(priority) > s->max_level_syslog)
> +                return;
> +
> +        /* First: priority field Second: Version  '<pri>version' */
> +        snprintf(header_priority, sizeof(header_priority), "<%i>%i ", priority, RFC_5424_PROTOCOL);
> +        IOVEC_SET_STRING(iov[n++], header_priority);
> +
> +        /* Third: timestamp */
> +        format_rfc3339_timestamp(tv, header_time, sizeof(header_time));
> +        IOVEC_SET_STRING(iov[n++], header_time);
> +
> +        /* Fourth: hostname */
> +        if (s->hostname) {
> +                IOVEC_SET_STRING(iov[n++], s->hostname);
> +                IOVEC_SET_STRING(iov[n++], " ");
> +        }
> +
> +        /* Fifth: app-name or tag */
> +        if (identifier) {
> +                IOVEC_SET_STRING(iov[n++], identifier);
> +                IOVEC_SET_STRING(iov[n++], " ");
> +        } else {
> +                IOVEC_SET_STRING(iov[n++], RFC_5424_NILVALUE);
> +                IOVEC_SET_STRING(iov[n++], " ");
> +        }
> +
> +        /* Sixth: procid */
> +        if (ucred) {
> +                xsprintf(header_pid, PID_FMT , ucred->pid);
> +
> +                IOVEC_SET_STRING(iov[n++], header_pid);
> +                IOVEC_SET_STRING(iov[n++], " ");
> +        } else {
> +                IOVEC_SET_STRING(iov[n++], RFC_5424_NILVALUE);
> +                IOVEC_SET_STRING(iov[n++], " ");
> +        }
> +
> +        /* Seventh: msgid */
> +        IOVEC_SET_STRING(iov[n++], RFC_5424_NILVALUE);
> +        IOVEC_SET_STRING(iov[n++], " ");
> +
> +        /* Eighth: [structured-data] */
> +        IOVEC_SET_STRING(iov[n++], RFC_5424_NILVALUE);
> +        IOVEC_SET_STRING(iov[n++], " ");
> +
> +        /* Ninth: message */
> +        IOVEC_SET_STRING(iov[n++], message);
> +
> +        syslog_network_send(s, iov, n, priority);
> +}
> +
> +static int syslog_network_fd(Server *s) {
> +        const int ttl = 255;
> +        const int one = 1;
> +        int fd, r;
> +
> +        assert(s);
> +
> +        fd = socket(s->syslog_addr.sockaddr.sa.sa_family, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
> +        if (fd < 0)
> +                return -errno;
> +
> +        r = setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &one, sizeof(one));
> +        if (r < 0) {
> +                r = -errno;
> +                goto fail;
> +        }
> +
> +        r = setsockopt(fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl));
> +        if (r < 0) {
> +                r = -errno;
> +                goto fail;
> +        }
> +
> +        r = setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP, &one, sizeof(one));
> +        if (r < 0) {
> +                r = -errno;
> +                goto fail;
> +        }
> +
> +        s->syslog_network_fd = fd;
> +
> +        return fd;
> +
> + fail:
> +        fd = safe_close(fd);
> +        return r;
> +}
> +
> +int server_open_syslog_network_socket(Server *s) {
> +        int r;
> +
> +        assert(s);
> +
> +        s->hostname = gethostname_malloc();
Do you cover the case where hostname changes after we open the socket?
> +        if (!s->hostname) {
> +                r = -ENOMEM;
> +                goto fail;
> +        }
> +
> +        if (s->syslog_addr.sockaddr.sa.sa_family == AF_INET || s->syslog_addr.sockaddr.sa.sa_family == AF_INET6) {
> +
> +                r = syslog_network_fd(s);
Don't you want to embed syslog_network_fd in to this function? If you
don't, I think the name is a bit confusing as we also have
s->syslog_network_fd.
> +                if (r < 0)
> +                        goto fail;
> +        } else {
> +                r = -EAFNOSUPPORT;
> +                goto fail;
> +        }
> +
> +        s->syslog_network_rate_limit = journal_rate_limit_new(s->rate_limit_interval, s->rate_limit_burst);
> +        if (!s->syslog_network_rate_limit) {
> +                r = -ENOMEM;
> +                goto fail;
> +        }
> +
> +        return r;
> + fail:
> +        s->forward_to_network = false;
> +        return r;
> +}
> diff --git a/src/journal/journald-syslog.c b/src/journal/journald-syslog.c
> index 7d545ca..4ecbc43 100644
> --- a/src/journal/journald-syslog.c
> +++ b/src/journal/journald-syslog.c
> @@ -336,6 +336,9 @@ void server_process_syslog_message(
>          syslog_skip_date((char**) &buf);
>          syslog_parse_identifier(&buf, &identifier, &pid);
>
> +        if (s->forward_to_network)
> +                server_forward_syslog_network(s, priority, identifier, buf, ucred, tv);
> +
>          if (s->forward_to_kmsg)
>                  server_forward_kmsg(s, priority, identifier, buf, ucred);
>
> diff --git a/src/journal/journald-syslog.h b/src/journal/journald-syslog.h
> index 3774ebd..b239825 100644
> --- a/src/journal/journald-syslog.h
> +++ b/src/journal/journald-syslog.h
> @@ -26,8 +26,10 @@
>  int syslog_fixup_facility(int priority) _const_;
>
>  size_t syslog_parse_identifier(const char **buf, char **identifier, char **pid);
> +void format_rfc3339_timestamp(const struct timeval *tv, char *header_time, size_t header_size);
>
>  void server_forward_syslog(Server *s, int priority, const char *identifier, const char *message, const struct ucred *ucred, const struct timeval *tv);
> +void server_forward_syslog_network(Server *s, int priority, const char *identifier, const char *message, const struct ucred *ucred, const struct timeval *tv);
>
>  void server_process_syslog_message(Server *s, const char *buf, const struct ucred *ucred, const struct timeval *tv, const char *label, size_t label_len);
>  int server_open_syslog_socket(Server *s);
> --
> 2.1.0
>
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