log: downgrade syslog connection failure message since it might happen during normal...

[elogind.git] / src / log.c

diff --git a/src/log.c b/src/log.c
index d0d98ddf753ac14bc97abc7708994e1cefd2c148..cc636a2dfac16e7fab8b1206717d3c1eb00e1a14 100644 (file)
--- a/src/log.c
+++ b/src/log.c
@@ -32,7 +32,6 @@
 #include "macro.h"
 
 #define SYSLOG_TIMEOUT_USEC (5*USEC_PER_SEC)
-#define LOG_BUFFER_MAX 1024
 
 static LogTarget log_target = LOG_TARGET_CONSOLE;
 static int log_max_level = LOG_INFO;
@@ -41,6 +40,8 @@ static int console_fd = STDERR_FILENO;
 static int syslog_fd = -1;
 static int kmsg_fd = -1;
 
+static bool syslog_is_stream = false;
+
 static bool show_color = false;
 static bool show_location = false;
 
@@ -95,7 +96,7 @@ static int log_open_kmsg(void) {
                 return 0;
 
         if ((kmsg_fd = open("/dev/kmsg", O_WRONLY|O_NOCTTY|O_CLOEXEC)) < 0) {
-                log_info("Failed to open /dev/kmsg for logging: %s", strerror(errno));
+                log_error("Failed to open /dev/kmsg for logging: %s", strerror(errno));
                 return -errno;
         }
 
@@ -113,46 +114,70 @@ void log_close_syslog(void) {
         syslog_fd = -1;
 }
 
+static int create_log_socket(int type) {
+        struct timeval tv;
+        int fd;
+
+        if ((fd = socket(AF_UNIX, type|SOCK_CLOEXEC, 0)) < 0)
+                return -errno;
+
+        /* Make sure we don't block for more than 5s when talking to
+         * syslog */
+        timeval_store(&tv, SYSLOG_TIMEOUT_USEC);
+        if (setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv)) < 0) {
+                close_nointr_nofail(fd);
+                return -errno;
+        }
+
+        return fd;
+}
+
 static int log_open_syslog(void) {
         union {
                 struct sockaddr sa;
                 struct sockaddr_un un;
         } sa;
-        struct timeval tv;
         int r;
 
         if (syslog_fd >= 0)
                 return 0;
 
-        if ((syslog_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0)) < 0) {
-                r = -errno;
-                goto fail;
-        }
-
-        /* Make sure we don't block for more than 5s when talking to
-         * syslog */
-        timeval_store(&tv, SYSLOG_TIMEOUT_USEC);
-        if (setsockopt(syslog_fd, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv)) < 0) {
-                r = -errno;
-                goto fail;
-        }
-
         zero(sa);
         sa.un.sun_family = AF_UNIX;
         strncpy(sa.un.sun_path, "/dev/log", sizeof(sa.un.sun_path));
 
-        if (connect(syslog_fd, &sa.sa, sizeof(sa)) < 0) {
+        if ((syslog_fd = create_log_socket(SOCK_DGRAM)) < 0) {
                 r = -errno;
                 goto fail;
         }
 
+        if (connect(syslog_fd, &sa.sa, sizeof(sa)) < 0) {
+                close_nointr_nofail(syslog_fd);
+
+                /* Some legacy syslog systems still use stream
+                 * sockets. They really shouldn't. But what can we
+                 * do... */
+                if ((syslog_fd = create_log_socket(SOCK_STREAM)) < 0) {
+                        r = -errno;
+                        goto fail;
+                }
+
+                if (connect(syslog_fd, &sa.sa, sizeof(sa)) < 0) {
+                        r = -errno;
+                        goto fail;
+                }
+
+                syslog_is_stream = true;
+        } else
+                syslog_is_stream = false;
+
         log_debug("Succesfully opened syslog for logging.");
 
         return 0;
 
 fail:
         log_close_syslog();
-        log_info("Failed to open syslog for logging: %s", strerror(-r));
+        log_debug("Failed to open syslog for logging: %s", strerror(-r));
         return r;
 }
 
@@ -187,6 +212,9 @@ int log_open(void) {
                 }
 
         log_close_syslog();
+
+        /* Get the real /dev/console if we are PID=1, hence reopen */
+        log_close_console();
         return log_open_console();
 }
 
@@ -275,12 +303,26 @@ static int write_to_syslog(
         IOVEC_SET_STRING(iovec[3], header_pid);
         IOVEC_SET_STRING(iovec[4], buffer);
 
+        /* When using syslog via SOCK_STREAM separate the messages by NUL chars */
+        if (syslog_is_stream)
+                iovec[4].iov_len++;
+
         zero(msghdr);
         msghdr.msg_iov = iovec;
         msghdr.msg_iovlen = ELEMENTSOF(iovec);
 
-        if (sendmsg(syslog_fd, &msghdr, MSG_NOSIGNAL) < 0)
-                return -errno;
+        for (;;) {
+                ssize_t n;
+
+                if ((n = sendmsg(syslog_fd, &msghdr, MSG_NOSIGNAL)) < 0)
+                        return -errno;
+
+                if (!syslog_is_stream ||
+                    (size_t) n >= IOVEC_TOTAL_SIZE(iovec, ELEMENTSOF(iovec)))
+                        break;
+
+                IOVEC_INCREMENT(iovec, ELEMENTSOF(iovec), n);
+        }
 
         return 1;
 }
@@ -400,7 +442,7 @@ int log_meta(
         const char *func,
         const char *format, ...) {
 
-        char buffer[LOG_BUFFER_MAX];
+        char buffer[LINE_MAX];
         int saved_errno, r;
         va_list ap;
 
@@ -427,7 +469,7 @@ void log_assert(
         const char *func,
         const char *format, ...) {
 
-        static char buffer[LOG_BUFFER_MAX];
+        static char buffer[LINE_MAX];
         int saved_errno = errno;
         va_list ap;
 
@@ -480,10 +522,9 @@ void log_parse_environment(void) {
                 if (log_show_color_from_string(e) < 0)
                         log_warning("Failed to parse bool %s. Ignoring.", e);
 
-        if ((e = getenv("SYSTEMD_LOG_LOCATION"))) {
+        if ((e = getenv("SYSTEMD_LOG_LOCATION")))
                 if (log_show_location_from_string(e) < 0)
                         log_warning("Failed to parse bool %s. Ignoring.", e);
-        }
 }
 
 LogTarget log_get_target(void) {