syslogd: send '\n'-terminated messages over the network.

fully closes bug 1574. +8 bytes.

1 files changed, 21 insertions, 15 deletions

diff --git a/sysklogd/syslogd.c b/sysklogd/syslogd.c
index f3ebf9392..457f38103 100644
--- a/sysklogd/syslogd.c
+++ b/sysklogd/syslogd.c
@@ -370,13 +370,15 @@ static void parse_fac_prio_20(int pri, char *res20)
                 c_fac = facilitynames;
                 while (c_fac->c_name) {
                         if (c_fac->c_val != (LOG_FAC(pri) << 3)) {
-                                c_fac++; continue;
+                                c_fac++;
+                                continue;
                         }
                         /* facility is found, look for prio */
                         c_pri = prioritynames;
                         while (c_pri->c_name) {
                                 if (c_pri->c_val != LOG_PRI(pri)) {
-                                        c_pri++; continue;
+                                        c_pri++;
+                                        continue;
                                 }
                                 snprintf(res20, 20, "%s.%s",
                                                 c_fac->c_name, c_pri->c_name);
@@ -428,6 +430,9 @@ static void timestamp_and_log_internal(const char *msg)
         timestamp_and_log(LOG_SYSLOG | LOG_INFO, (char*)msg, 0);
 }
 
+/* tmpbuf[len] is a NUL byte (set by caller), but there can be other,
+ * embedded NULs. Split messages on each of these NULs, parse prio,
+ * escape control chars and log each locally. */
 static void split_escape_and_log(char *tmpbuf, int len)
 {
         char *p = tmpbuf;
@@ -556,30 +561,24 @@ static void do_syslogd(void)
                 size_t sz;
  read_again:
                 sz = safe_read(sock_fd, G.recvbuf, MAX_READ - 1);
-                if (sz < 0) {
+                if (sz < 0)
                         bb_perror_msg_and_die("read from /dev/log");
-                }
 
-                /* Drop trailing NULs (typically there is one NUL) */
+                /* Drop trailing '\n' and NULs (typically there is one NUL) */
                 while (1) {
                         if (sz == 0)
                                 goto read_again;
                         /* man 3 syslog says: "A trailing newline is added when needed".
                          * However, neither glibc nor uclibc do this:
                          * syslog(prio, "test")   sends "test\0" to /dev/log,
-                         * syslog(prio, "test\n") sends "test\n\0",
+                         * syslog(prio, "test\n") sends "test\n\0".
                          * IOW: newline is passed verbatim!
                          * I take it to mean that it's syslogd's job
-                         * to make those look identical in the log files */
-                        if (G.recvbuf[sz-1] && G.recvbuf[sz-1] != '\n')
+                         * to make those look identical in the log files. */
+                        if (G.recvbuf[sz-1] != '\0' && G.recvbuf[sz-1] != '\n')
                                 break;
                         sz--;
                 }
-                /* Maybe we need to add '\n' here, not later?
-                 * It looks like stock syslogd does send '\n' over network,
-                 * but we do not (see sendto below) */
-                G.recvbuf[sz] = '\0'; /* make sure it *is* NUL terminated */
-
                 /* TODO: maybe suppress duplicates? */
 #if ENABLE_FEATURE_REMOTE_LOG
                 /* We are not modifying log messages in any way before send */
@@ -590,14 +589,21 @@ static void do_syslogd(void)
                                 if (-1 == G.remoteFD)
                                         goto no_luck;
                         }
+                        /* Stock syslogd sends it '\n'-terminated
+                         * over network, mimic that */
+                        G.recvbuf[sz] = '\n';
                         /* send message to remote logger, ignore possible error */
-                        sendto(G.remoteFD, G.recvbuf, sz, MSG_DONTWAIT,
+                        /* TODO: on some errors, close and set G.remoteFD to -1
+                         * so that DNS resolution and connect is retried? */
+                        sendto(G.remoteFD, G.recvbuf, sz+1, MSG_DONTWAIT,
                                     &G.remoteAddr->u.sa, G.remoteAddr->len);
  no_luck: ;
                 }
 #endif
-                if (!ENABLE_FEATURE_REMOTE_LOG || (option_mask32 & OPT_locallog))
+                if (!ENABLE_FEATURE_REMOTE_LOG || (option_mask32 & OPT_locallog)) {
+                        G.recvbuf[sz] = '\0'; /* ensure it *is* NUL terminated */
                         split_escape_and_log(G.recvbuf, sz);
+                }
         } /* for (;;) */
 }