Adding upstream version 247.3.upstream/247.3upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 527 insertions, 0 deletions

diff --git a/src/journal/journald-syslog.c b/src/journal/journald-syslog.c
new file mode 100644
index 0000000..925bd50
--- /dev/null
+++ b/src/journal/journald-syslog.c
@@ -0,0 +1,527 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <stddef.h>
+#include <sys/epoll.h>
+#include <unistd.h>
+
+#include "sd-messages.h"
+
+#include "alloc-util.h"
+#include "fd-util.h"
+#include "format-util.h"
+#include "io-util.h"
+#include "journald-console.h"
+#include "journald-kmsg.h"
+#include "journald-server.h"
+#include "journald-syslog.h"
+#include "journald-wall.h"
+#include "process-util.h"
+#include "selinux-util.h"
+#include "socket-util.h"
+#include "stdio-util.h"
+#include "string-util.h"
+#include "syslog-util.h"
+
+/* Warn once every 30s if we missed syslog message */
+#define WARN_FORWARD_SYSLOG_MISSED_USEC (30 * USEC_PER_SEC)
+
+static void forward_syslog_iovec(
+                Server *s,
+                const struct iovec *iovec,
+                unsigned n_iovec,
+                const struct ucred *ucred,
+                const struct timeval *tv) {
+
+        union sockaddr_union sa;
+
+        struct msghdr msghdr = {
+                .msg_iov = (struct iovec *) iovec,
+                .msg_iovlen = n_iovec,
+        };
+        struct cmsghdr *cmsg;
+        CMSG_BUFFER_TYPE(CMSG_SPACE(sizeof(struct ucred))) control;
+        const char *j;
+        int r;
+
+        assert(s);
+        assert(iovec);
+        assert(n_iovec > 0);
+
+        j = strjoina(s->runtime_directory, "/syslog");
+        r = sockaddr_un_set_path(&sa.un, j);
+        if (r < 0) {
+                log_debug_errno(r, "Forwarding socket path %s too long for AF_UNIX, not forwarding: %m", j);
+                return;
+        }
+
+        msghdr.msg_name = &sa.sa;
+        msghdr.msg_namelen = r;
+
+        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) {
+                s->n_forward_syslog_missed++;
+                return;
+        }
+
+        if (ucred && IN_SET(errno, ESRCH, EPERM)) {
+                struct ucred u;
+
+                /* Hmm, presumably the sender process vanished
+                 * by now, or we don't have CAP_SYS_AMDIN, so
+                 * let's fix it as good as we can, and retry */
+
+                u = *ucred;
+                u.pid = getpid_cached();
+                memcpy(CMSG_DATA(cmsg), &u, sizeof(struct ucred));
+
+                if (sendmsg(s->syslog_fd, &msghdr, MSG_NOSIGNAL) >= 0)
+                        return;
+
+                if (errno == EAGAIN) {
+                        s->n_forward_syslog_missed++;
+                        return;
+                }
+        }
+
+        if (errno != ENOENT)
+                log_debug_errno(errno, "Failed to forward syslog message: %m");
+}
+
+static void forward_syslog_raw(Server *s, int priority, const char *buffer, size_t buffer_len, const struct ucred *ucred, const struct timeval *tv) {
+        struct iovec iovec;
+
+        assert(s);
+        assert(buffer);
+
+        if (LOG_PRI(priority) > s->max_level_syslog)
+                return;
+
+        iovec = IOVEC_MAKE((char *) buffer, buffer_len);
+        forward_syslog_iovec(s, &iovec, 1, ucred, tv);
+}
+
+void server_forward_syslog(Server *s, int priority, const char *identifier, const char *message, const struct ucred *ucred, const struct timeval *tv) {
+        struct iovec iovec[5];
+        char header_priority[DECIMAL_STR_MAX(priority) + 3], header_time[64],
+             header_pid[STRLEN("[]: ") + DECIMAL_STR_MAX(pid_t) + 1];
+        int n = 0;
+        time_t t;
+        struct tm tm;
+        _cleanup_free_ 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 */
+        xsprintf(header_priority, "<%i>", priority);
+        iovec[n++] = IOVEC_MAKE_STRING(header_priority);
+
+        /* Second: timestamp */
+        t = tv ? tv->tv_sec : ((time_t) (now(CLOCK_REALTIME) / USEC_PER_SEC));
+        if (!localtime_r(&t, &tm))
+                return;
+        if (strftime(header_time, sizeof(header_time), "%h %e %T ", &tm) <= 0)
+                return;
+        iovec[n++] = IOVEC_MAKE_STRING(header_time);
+
+        /* Third: identifier and PID */
+        if (ucred) {
+                if (!identifier) {
+                        (void) get_process_comm(ucred->pid, &ident_buf);
+                        identifier = ident_buf;
+                }
+
+                xsprintf(header_pid, "["PID_FMT"]: ", ucred->pid);
+
+                if (identifier)
+                        iovec[n++] = IOVEC_MAKE_STRING(identifier);
+
+                iovec[n++] = IOVEC_MAKE_STRING(header_pid);
+        } else if (identifier) {
+                iovec[n++] = IOVEC_MAKE_STRING(identifier);
+                iovec[n++] = IOVEC_MAKE_STRING(": ");
+        }
+
+        /* Fourth: message */
+        iovec[n++] = IOVEC_MAKE_STRING(message);
+
+        forward_syslog_iovec(s, iovec, n, ucred, tv);
+}
+
+int syslog_fixup_facility(int priority) {
+
+        if ((priority & LOG_FACMASK) == 0)
+                return (priority & LOG_PRIMASK) | LOG_USER;
+
+        return priority;
+}
+
+size_t syslog_parse_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 0;
+
+        e = l;
+        l--;
+
+        if (l > 0 && 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;
+
+        /* Single space is used as separator */
+        if (p[e] != '\0' && strchr(WHITESPACE, p[e]))
+                e++;
+
+        l = (p - *buf) + e;
+        *buf = p + e;
+        return l;
+}
+
+static int syslog_skip_timestamp(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, *t;
+        unsigned i;
+
+        assert(buf);
+        assert(*buf);
+
+        for (i = 0, p = *buf; i < ELEMENTSOF(sequence); i++, p++) {
+                if (!*p)
+                        return 0;
+
+                switch (sequence[i]) {
+
+                case SPACE:
+                        if (*p != ' ')
+                                return 0;
+                        break;
+
+                case SPACE_OR_NUMBER:
+                        if (*p == ' ')
+                                break;
+
+                        _fallthrough_;
+                case NUMBER:
+                        if (*p < '0' || *p > '9')
+                                return 0;
+
+                        break;
+
+                case LETTER:
+                        if (!(*p >= 'A' && *p <= 'Z') &&
+                            !(*p >= 'a' && *p <= 'z'))
+                                return 0;
+
+                        break;
+
+                case COLON:
+                        if (*p != ':')
+                                return 0;
+                        break;
+
+                }
+        }
+
+        t = *buf;
+        *buf = p;
+        return p - t;
+}
+
+void server_process_syslog_message(
+                Server *s,
+                const char *buf,
+                size_t raw_len,
+                const struct ucred *ucred,
+                const struct timeval *tv,
+                const char *label,
+                size_t label_len) {
+
+        char *t, syslog_priority[sizeof("PRIORITY=") + DECIMAL_STR_MAX(int)],
+                 syslog_facility[sizeof("SYSLOG_FACILITY=") + DECIMAL_STR_MAX(int)];
+        const char *msg, *syslog_ts, *a;
+        _cleanup_free_ char *identifier = NULL, *pid = NULL,
+                *dummy = NULL, *msg_msg = NULL, *msg_raw = NULL;
+        int priority = LOG_USER | LOG_INFO, r;
+        ClientContext *context = NULL;
+        struct iovec *iovec;
+        size_t n = 0, m, i, leading_ws, syslog_ts_len;
+        bool store_raw;
+
+        assert(s);
+        assert(buf);
+        /* The message cannot be empty. */
+        assert(raw_len > 0);
+        /* The buffer NUL-terminated and can be used a string. raw_len is the length
+         * without the terminating NUL byte, the buffer is actually one bigger. */
+        assert(buf[raw_len] == '\0');
+
+        if (ucred && pid_is_valid(ucred->pid)) {
+                r = client_context_get(s, ucred->pid, ucred, label, label_len, NULL, &context);
+                if (r < 0)
+                        log_warning_errno(r, "Failed to retrieve credentials for PID " PID_FMT ", ignoring: %m", ucred->pid);
+        }
+
+        /* We are creating a copy of the message because we want to forward the original message
+           verbatim to the legacy syslog implementation */
+        for (i = raw_len; i > 0; i--)
+                if (!strchr(WHITESPACE, buf[i-1]))
+                        break;
+
+        leading_ws = strspn(buf, WHITESPACE);
+
+        if (i == 0)
+                /* The message contains only whitespaces */
+                msg = buf + raw_len;
+        else if (i == raw_len)
+                /* Nice! No need to strip anything on the end, let's optimize this a bit */
+                msg = buf + leading_ws;
+        else {
+                msg = dummy = new(char, i - leading_ws + 1);
+                if (!dummy) {
+                        log_oom();
+                        return;
+                }
+
+                memcpy(dummy, buf + leading_ws, i - leading_ws);
+                dummy[i - leading_ws] = 0;
+        }
+
+        /* We will add the SYSLOG_RAW= field when we stripped anything
+         * _or_ if the input message contained NUL bytes. */
+        store_raw = msg != buf || strlen(msg) != raw_len;
+
+        syslog_parse_priority(&msg, &priority, true);
+
+        if (!client_context_test_priority(context, priority))
+                return;
+
+        syslog_ts = msg;
+        syslog_ts_len = syslog_skip_timestamp(&msg);
+        if (syslog_ts_len == 0)
+                /* We failed to parse the full timestamp, store the raw message too */
+                store_raw = true;
+
+        syslog_parse_identifier(&msg, &identifier, &pid);
+
+        if (s->forward_to_syslog)
+                forward_syslog_raw(s, priority, buf, raw_len, ucred, tv);
+
+        if (s->forward_to_kmsg)
+                server_forward_kmsg(s, priority, identifier, msg, ucred);
+
+        if (s->forward_to_console)
+                server_forward_console(s, priority, identifier, msg, ucred);
+
+        if (s->forward_to_wall)
+                server_forward_wall(s, priority, identifier, msg, ucred);
+
+        m = N_IOVEC_META_FIELDS + 8 + client_context_extra_fields_n_iovec(context);
+        iovec = newa(struct iovec, m);
+
+        iovec[n++] = IOVEC_MAKE_STRING("_TRANSPORT=syslog");
+
+        xsprintf(syslog_priority, "PRIORITY=%i", priority & LOG_PRIMASK);
+        iovec[n++] = IOVEC_MAKE_STRING(syslog_priority);
+
+        if (priority & LOG_FACMASK) {
+                xsprintf(syslog_facility, "SYSLOG_FACILITY=%i", LOG_FAC(priority));
+                iovec[n++] = IOVEC_MAKE_STRING(syslog_facility);
+        }
+
+        if (identifier) {
+                a = strjoina("SYSLOG_IDENTIFIER=", identifier);
+                iovec[n++] = IOVEC_MAKE_STRING(a);
+        }
+
+        if (pid) {
+                a = strjoina("SYSLOG_PID=", pid);
+                iovec[n++] = IOVEC_MAKE_STRING(a);
+        }
+
+        if (syslog_ts_len > 0) {
+                const size_t hlen = STRLEN("SYSLOG_TIMESTAMP=");
+
+                t = newa(char, hlen + syslog_ts_len);
+                memcpy(t, "SYSLOG_TIMESTAMP=", hlen);
+                memcpy(t + hlen, syslog_ts, syslog_ts_len);
+
+                iovec[n++] = IOVEC_MAKE(t, hlen + syslog_ts_len);
+        }
+
+        msg_msg = strjoin("MESSAGE=", msg);
+        if (!msg_msg) {
+                log_oom();
+                return;
+        }
+        iovec[n++] = IOVEC_MAKE_STRING(msg_msg);
+
+        if (store_raw) {
+                const size_t hlen = STRLEN("SYSLOG_RAW=");
+
+                msg_raw = new(char, hlen + raw_len);
+                if (!msg_raw) {
+                        log_oom();
+                        return;
+                }
+
+                memcpy(msg_raw, "SYSLOG_RAW=", hlen);
+                memcpy(msg_raw + hlen, buf, raw_len);
+
+                iovec[n++] = IOVEC_MAKE(msg_raw, hlen + raw_len);
+        }
+
+        server_dispatch_message(s, iovec, n, m, context, tv, priority, 0);
+}
+
+int server_open_syslog_socket(Server *s, const char *syslog_socket) {
+        int r;
+
+        assert(s);
+        assert(syslog_socket);
+
+        if (s->syslog_fd < 0) {
+                union sockaddr_union sa;
+                socklen_t sa_len;
+
+                r = sockaddr_un_set_path(&sa.un, syslog_socket);
+                if (r < 0)
+                        return log_error_errno(r, "Unable to use namespace path %s for AF_UNIX socket: %m", syslog_socket);
+                sa_len = r;
+
+                s->syslog_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
+                if (s->syslog_fd < 0)
+                        return log_error_errno(errno, "socket() failed: %m");
+
+                (void) sockaddr_un_unlink(&sa.un);
+
+                r = bind(s->syslog_fd, &sa.sa, sa_len);
+                if (r < 0)
+                        return log_error_errno(errno, "bind(%s) failed: %m", sa.un.sun_path);
+
+                (void) chmod(sa.un.sun_path, 0666);
+        } else
+                (void) fd_nonblock(s->syslog_fd, true);
+
+        r = setsockopt_int(s->syslog_fd, SOL_SOCKET, SO_PASSCRED, true);
+        if (r < 0)
+                return log_error_errno(r, "SO_PASSCRED failed: %m");
+
+        if (mac_selinux_use()) {
+                r = setsockopt_int(s->syslog_fd, SOL_SOCKET, SO_PASSSEC, true);
+                if (r < 0)
+                        log_warning_errno(r, "SO_PASSSEC failed: %m");
+        }
+
+        r = setsockopt_int(s->syslog_fd, SOL_SOCKET, SO_TIMESTAMP, true);
+        if (r < 0)
+                return log_error_errno(r, "SO_TIMESTAMP failed: %m");
+
+        r = sd_event_add_io(s->event, &s->syslog_event_source, s->syslog_fd, EPOLLIN, server_process_datagram, s);
+        if (r < 0)
+                return log_error_errno(r, "Failed to add syslog server fd to event loop: %m");
+
+        r = sd_event_source_set_priority(s->syslog_event_source, SD_EVENT_PRIORITY_NORMAL+5);
+        if (r < 0)
+                return log_error_errno(r, "Failed to adjust syslog event source priority: %m");
+
+        return 0;
+}
+
+void server_maybe_warn_forward_syslog_missed(Server *s) {
+        usec_t n;
+
+        assert(s);
+
+        if (s->n_forward_syslog_missed <= 0)
+                return;
+
+        n = now(CLOCK_MONOTONIC);
+        if (s->last_warn_forward_syslog_missed + WARN_FORWARD_SYSLOG_MISSED_USEC > n)
+                return;
+
+        server_driver_message(s, 0,
+                              "MESSAGE_ID=" SD_MESSAGE_FORWARD_SYSLOG_MISSED_STR,
+                              LOG_MESSAGE("Forwarding to syslog missed %u messages.",
+                                          s->n_forward_syslog_missed),
+                              NULL);
+
+        s->n_forward_syslog_missed = 0;
+        s->last_warn_forward_syslog_missed = n;
+}