readahead: preload pack file

[elogind.git] / src / log.c

diff --git a/src/log.c b/src/log.c
index 3c42e8e51795dc4f7928707c9d7f9a46516f06a5..2dd3e978ff1f2e1a0611ef0f7d8935f70cb719b5 100644 (file)
--- a/src/log.c
+++ b/src/log.c
@@ -40,6 +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;
 
@@ -112,39 +114,63 @@ 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;
@@ -248,11 +274,6 @@ static int write_to_syslog(
         char header_priority[16], header_time[64], header_pid[16];
         struct iovec iovec[5];
         struct msghdr msghdr;
-        union {
-                struct cmsghdr cmsghdr;
-                uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
-        } control;
-        struct ucred *ucred;
         time_t t;
         struct tm *tm;
 
@@ -279,24 +300,26 @@ static int write_to_syslog(
         IOVEC_SET_STRING(iovec[3], header_pid);
         IOVEC_SET_STRING(iovec[4], buffer);
 
-        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 = getpid();
-        ucred->uid = getuid();
-        ucred->gid = getgid();
+        /* When using syslog via SOCK_STREAM seperate the messages by NUL chars */
+        if (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;
 
-        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;
 }