spawn: do not use syslog calls in the child process

The syslog routines uses private mutex so it can cause
various crashes and other misbehaviour.

Use pipes to send messages from the child processes.

diff --git a/src/main.c b/src/main.c
index c3fd56b46ee43a67b66501042d5755a1d16ac9f3..b98fdcca96f22127521ef6ce2f4285ff76f5ab86 100644 (file)
--- a/src/main.c
+++ b/src/main.c
@@ -795,6 +795,8 @@ main(int argc, char **argv)
    * Initialize subsystems
    */
 
+  spawn_init();
+
   dbus_server_init(opt_dbus, opt_dbus_session);
 
   intlconv_init();
@@ -943,6 +945,7 @@ main(int argc, char **argv)
   tvhftrace("main", intlconv_done);
   tvhftrace("main", urlparse_done);
   tvhftrace("main", idnode_done);
+  tvhftrace("main", spawn_done);
 
   tvhlog(LOG_NOTICE, "STOP", "Exiting HTS Tvheadend");
   tvhlog_end();

diff --git a/src/spawn.c b/src/spawn.c
index f3530b34235479e7cc8629057b266d984d5eddb6..a6748ea388b9f8ae80f9573902b8ca812bba762b 100644 (file)
--- a/src/spawn.c
+++ b/src/spawn.c
@@ -43,12 +43,87 @@ pthread_mutex_t spawn_mutex = PTHREAD_MUTEX_INITIALIZER;
 
 static LIST_HEAD(, spawn) spawns;
 
+static char *spawn_info_buf = NULL;
+static char *spawn_error_buf = NULL;
+
+static th_pipe_t spawn_pipe_info;
+static th_pipe_t spawn_pipe_error;
+
 typedef struct spawn {
   LIST_ENTRY(spawn) link;
   pid_t pid;
   const char *name;
 } spawn_t;
 
+/*
+ *
+ */
+#define SPAWN_PIPE_READ_SIZE 4096
+
+static void
+spawn_pipe_read( th_pipe_t *p, char **_buf, int level )
+{
+  char *buf = *_buf, *s;
+  size_t len;
+  int r;
+
+  if (buf == NULL) {
+    buf = malloc(SPAWN_PIPE_READ_SIZE);
+    buf[0] = '\0';
+    buf[SPAWN_PIPE_READ_SIZE - 1] = 0;
+    *_buf = buf;
+  }
+  while (1) {
+    len = strlen(buf);
+    r = read(p->rd, buf + len, SPAWN_PIPE_READ_SIZE - 1 - len);
+    if (r < 1) {
+      if (errno == EAGAIN)
+        break;
+      if (ERRNO_AGAIN(errno))
+        continue;
+      break;
+    }
+    while ((s = strchr(buf, '\n')) != NULL) {
+      *s++ = '\0';
+      tvhlog(level, "spawn", "%s", buf);
+      memmove(buf, s, strlen(s) + 1);
+    }
+    if (strlen(buf) == SPAWN_PIPE_READ_SIZE - 1) {
+      tvherror("spawn", "pipe buffer full");
+      buf[0] = '\0';
+    }
+  }
+}
+
+static void
+spawn_pipe_write( th_pipe_t *p, const char *fmt, va_list ap )
+{
+  char buf[512];
+
+  vsnprintf(buf, sizeof(buf), fmt, ap);
+  write(p->wr, buf, strlen(buf));
+}
+
+void
+spawn_info( const char *fmt, ... )
+{
+  va_list ap;
+
+  va_start(ap, fmt);
+  spawn_pipe_write(&spawn_pipe_info, fmt, ap);
+  va_end(ap);
+}
+
+void
+spawn_error( const char *fmt, ... )
+{
+  va_list ap;
+
+  va_start(ap, fmt);
+  spawn_pipe_write(&spawn_pipe_error, fmt, ap);
+  va_end(ap);
+}
+
 /*
  * Search PATH for executable
  */
@@ -93,6 +168,9 @@ spawn_reap(char *stxt, size_t stxtlen)
   int status, res;
   spawn_t *s;
 
+  spawn_pipe_read(&spawn_pipe_info, &spawn_info_buf, LOG_INFO);
+  spawn_pipe_read(&spawn_pipe_error, &spawn_error_buf, LOG_ERR);
+
   pid = waitpid(-1, &status, WNOHANG);
   if(pid < 1)
     return -EAGAIN;
@@ -206,9 +284,8 @@ spawn_and_store_stdout(const char *prog, char *argv[], char **outp)
 
     f = open("/dev/null", O_RDWR);
     if(f == -1) {
-      syslog(LOG_ERR, 
-            "spawn: pid %d cannot open /dev/null for redirect %s -- %s",
-            getpid(), prog, strerror(errno));
+      spawn_error("pid %d cannot open /dev/null for redirect %s -- %s",
+                  getpid(), prog, strerror(errno));
       exit(1);
     }
 
@@ -216,9 +293,11 @@ spawn_and_store_stdout(const char *prog, char *argv[], char **outp)
     dup2(f, 2);
     close(f);
 
+    spawn_info("Executing \"%s\"\n", prog);
+
     execve(prog, argv, environ);
-    syslog(LOG_ERR, "spawn: pid %d cannot execute %s -- %s",
-          getpid(), prog, strerror(errno));
+    spawn_error("pid %d cannot execute %s -- %s\n",
+                getpid(), prog, strerror(errno));
     exit(1);
   }
 
@@ -264,10 +343,10 @@ spawnv(const char *prog, char *argv[])
   if(p == 0) {
     close(0);
     close(2);
-    syslog(LOG_INFO, "spawn: Executing \"%s\"", prog);
+    spawn_info("Executing \"%s\"\n", prog);
     execve(prog, argv, environ);
-    syslog(LOG_ERR, "spawn: pid %d cannot execute %s -- %s",
-          getpid(), prog, strerror(errno));
+    spawn_error("pid %d cannot execute %s -- %s\n",
+               getpid(), prog, strerror(errno));
     close(1);
     exit(1);
   }
@@ -275,3 +354,20 @@ spawnv(const char *prog, char *argv[])
   spawn_enq(prog, p);
   return 0;
 }
+
+/*
+ *
+ */
+void spawn_init(void)
+{
+  tvh_pipe(O_NONBLOCK, &spawn_pipe_info);
+  tvh_pipe(O_NONBLOCK, &spawn_pipe_error);
+}
+
+void spawn_done(void)
+{
+  tvh_pipe_close(&spawn_pipe_error);
+  tvh_pipe_close(&spawn_pipe_info);
+  free(spawn_error_buf);
+  free(spawn_info_buf);
+}

diff --git a/src/spawn.h b/src/spawn.h
index 64e734bffe9006813cacf45a3b4969919748e122..36ae3226ca39b3c496417ed81d16c3d11b273ad0 100644 (file)
--- a/src/spawn.h
+++ b/src/spawn.h
@@ -19,6 +19,10 @@
 #ifndef SPAWN_H
 #define SPAWN_H
 
+void spawn_info ( const char *fmt, ... );
+
+void spawn_error ( const char *fmt, ... );
+
 int find_exec ( const char *name, char *out, size_t len );
 
 int spawn_and_store_stdout(const char *prog, char *argv[], char **outp);
@@ -29,4 +33,8 @@ int spawn_reap(char *stxt, size_t stxtlen);
 
 void spawn_reaper(void);
 
+void spawn_init(void);
+
+void spawn_done(void);
+
 #endif /* SPAWN_H */