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

fully closes bug 1574. +8 bytes.

diff --git a/sysklogd/syslogd.c b/sysklogd/syslogd.c
index f3ebf93925f6e6343e38a1790bc3fe8e840a547c..457f381037ff26494d070b4180df7a1cc15a7c16 100644 (file)
--- 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 (;;) */
 }