syslog: allow multiple -R options

function                                             old     new   delta
syslogd_main                                        1082    1177     +95
init_data                                             72      64      -8

Signed-off-by: Thomas Geulig <geulig@nentec.de>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 50 insertions, 36 deletions

diff --git a/sysklogd/syslogd.c b/sysklogd/syslogd.c
index 8338d6be8..33203697d 100644
--- a/sysklogd/syslogd.c
+++ b/sysklogd/syslogd.c
@@ -57,6 +57,15 @@ struct shbuf_ds {
         char data[1];   /* data/messages */
 };
 
+#if ENABLE_FEATURE_REMOTE_LOG
+typedef struct {
+        int remoteFD;
+        unsigned last_dns_resolve;
+        len_and_sockaddr *remoteAddr;
+        const char *remoteHostname;
+} remoteHost_t;
+#endif
+
 /* Allows us to have smaller initializer. Ugly. */
 #define GLOBALS \
         const char *logFilePath;                \
@@ -73,11 +82,6 @@ IF_FEATURE_ROTATE_LOGFILE( \
         unsigned curFileSize;                   \
         smallint isRegular;                     \
 ) \
-IF_FEATURE_REMOTE_LOG( \
-        /* udp socket for remote logging */     \
-        int remoteFD;                           \
-        len_and_sockaddr* remoteAddr;           \
-) \
 IF_FEATURE_IPC_SYSLOG( \
         int shmid; /* ipc shared memory id */   \
         int s_semid; /* ipc semaphore id */     \
@@ -94,10 +98,8 @@ struct globals {
         GLOBALS
 
 #if ENABLE_FEATURE_REMOTE_LOG
-        unsigned last_dns_resolve;
-        char *remoteAddrStr;
+        llist_t *remoteHosts;
 #endif
-
 #if ENABLE_FEATURE_IPC_SYSLOG
         struct shbuf_ds *shbuf;
 #endif
@@ -127,9 +129,6 @@ static const struct init_globals init_data = {
         .logFileSize = 200 * 1024,
         .logFileRotate = 1,
 #endif
-#if ENABLE_FEATURE_REMOTE_LOG
-        .remoteFD = -1,
-#endif
 #if ENABLE_FEATURE_IPC_SYSLOG
         .shmid = -1,
         .s_semid = -1,
@@ -185,7 +184,7 @@ enum {
 #define OPTION_PARAM &opt_m, &G.logFilePath, &opt_l \
         IF_FEATURE_ROTATE_LOGFILE(,&opt_s) \
         IF_FEATURE_ROTATE_LOGFILE(,&opt_b) \
-        IF_FEATURE_REMOTE_LOG(    ,&G.remoteAddrStr) \
+        IF_FEATURE_REMOTE_LOG(    ,&remoteAddrList) \
         IF_FEATURE_IPC_SYSLOG(    ,&opt_C)
 
 
@@ -534,20 +533,20 @@ static NOINLINE int create_socket(void)
 }
 
 #if ENABLE_FEATURE_REMOTE_LOG
-static int try_to_resolve_remote(void)
+static int try_to_resolve_remote(remoteHost_t *rh)
 {
-        if (!G.remoteAddr) {
+        if (!rh->remoteAddr) {
                 unsigned now = monotonic_sec();
 
                 /* Don't resolve name too often - DNS timeouts can be big */
-                if ((now - G.last_dns_resolve) < DNS_WAIT_SEC)
+                if ((now - rh->last_dns_resolve) < DNS_WAIT_SEC)
                         return -1;
-                G.last_dns_resolve = now;
-                G.remoteAddr = host2sockaddr(G.remoteAddrStr, 514);
-                if (!G.remoteAddr)
+                rh->last_dns_resolve = now;
+                rh->remoteAddr = host2sockaddr(rh->remoteHostname, 514);
+                if (!rh->remoteAddr)
                         return -1;
         }
-        return socket(G.remoteAddr->u.sa.sa_family, SOCK_DGRAM, 0);
+        return socket(rh->remoteAddr->u.sa.sa_family, SOCK_DGRAM, 0);
 }
 #endif
 
@@ -555,6 +554,9 @@ static void do_syslogd(void) NORETURN;
 static void do_syslogd(void)
 {
         int sock_fd;
+#if ENABLE_FEATURE_REMOTE_LOG
+        llist_t *item;
+#endif
 #if ENABLE_FEATURE_SYSLOGD_DUP
         int last_sz = -1;
         char *last_buf;
@@ -620,23 +622,25 @@ static void do_syslogd(void)
                 last_sz = sz;
 #endif
 #if ENABLE_FEATURE_REMOTE_LOG
+                /* Stock syslogd sends it '\n'-terminated
+                 * over network, mimic that */
+                recvbuf[sz] = '\n';
+
                 /* We are not modifying log messages in any way before send */
                 /* Remote site cannot trust _us_ anyway and need to do validation again */
-                if (G.remoteAddrStr) {
-                        if (-1 == G.remoteFD) {
-                                G.remoteFD = try_to_resolve_remote();
-                                if (-1 == G.remoteFD)
-                                        goto no_luck;
+                for (item = G.remoteHosts; item != NULL; item = item->link) {
+                        remoteHost_t *rh = (remoteHost_t *)item->data;
+
+                        if (rh->remoteFD == -1) {
+                                rh->remoteFD = try_to_resolve_remote(rh);
+                                if (rh->remoteFD == -1)
+                                        continue;
                         }
-                        /* Stock syslogd sends it '\n'-terminated
-                         * over network, mimic that */
-                        recvbuf[sz] = '\n';
-                        /* send message to remote logger, ignore possible error */
+                        /* Send message to remote logger, ignore possible error */
                         /* TODO: on some errors, close and set G.remoteFD to -1
                          * so that DNS resolution and connect is retried? */
-                        sendto(G.remoteFD, recvbuf, sz+1, MSG_DONTWAIT,
-                                    &G.remoteAddr->u.sa, G.remoteAddr->len);
- no_luck: ;
+                        sendto(rh->remoteFD, recvbuf, sz+1, MSG_DONTWAIT,
+                                &(rh->remoteAddr->u.sa), rh->remoteAddr->len);
                 }
 #endif
                 if (!ENABLE_FEATURE_REMOTE_LOG || (option_mask32 & OPT_locallog)) {
@@ -656,17 +660,27 @@ static void do_syslogd(void)
 int syslogd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int syslogd_main(int argc UNUSED_PARAM, char **argv)
 {
-        char OPTION_DECL;
         int opts;
+        char OPTION_DECL;
+#if ENABLE_FEATURE_REMOTE_LOG
+        llist_t *remoteAddrList = NULL;
+#endif
 
         INIT_G();
+
+        /* No non-option params, -R can occur multiple times */
+        opt_complementary = "=0" IF_FEATURE_REMOTE_LOG(":R::");
+        opts = getopt32(argv, OPTION_STR, OPTION_PARAM);
 #if ENABLE_FEATURE_REMOTE_LOG
-        G.last_dns_resolve = monotonic_sec() - DNS_WAIT_SEC - 1;
+        while (remoteAddrList) {
+                remoteHost_t *rh = xzalloc(sizeof(*rh));
+                rh->remoteHostname = llist_pop(&remoteAddrList);
+                rh->remoteFD = -1;
+                rh->last_dns_resolve = monotonic_sec() - DNS_WAIT_SEC - 1;
+                llist_add_to(&G.remoteHosts, rh);
+        }
 #endif
 
-        /* do normal option parsing */
-        opt_complementary = "=0"; /* no non-option params */
-        opts = getopt32(argv, OPTION_STR, OPTION_PARAM);
 #ifdef SYSLOGD_MARK
         if (opts & OPT_mark) // -m
                 G.markInterval = xatou_range(opt_m, 0, INT_MAX/60) * 60;