FreeBSD Port: apcupsd-3.10.11

[Gary Bajaj]

apcupsd-3.10.11 rev 2 with --disable-pthreads set dumps core.

The fix is to remove --disable-pthreads and apply Adam Kropelin's (modified) patch - attached.

I have tested it this day and it seems to work perfectly in simulated power failure  and complete shutdown tests.


-------------- next part --------------
--- ./src/apcnis.c	Fri Jul 18 05:32:19 2003
+++ ./apcupsd-3.10.11-debug3/src/apcnis.c	Fri Feb  6 21:19:14 2004
@@ -197,7 +197,6 @@
    int newsockfd, sockfd, childpid;
    struct sockaddr_in cli_addr;       /* client's address */
    struct sockaddr_in serv_addr;      /* our address */
-   socklen_t clilen;
    int tlog;
    int turnon = 1;
    struct s_arg *arg;
@@ -269,11 +268,7 @@
       /* 
        * Wait for a connection from a client process.
        */
-       clilen = sizeof(cli_addr);
-       for (tlog=0; (newsockfd = accept(sockfd, (struct sockaddr *)&cli_addr, &clilen)) < 0; tlog -= 5*60 ) {
-	  if (errno == EINTR) {
-	     continue;
-	  }
+       for (tlog=0; (newsockfd = net_accept(sockfd, &cli_addr)) < 0; tlog -= 5*60 ) {
 	  if (tlog <= 0) {
 	     tlog = 60*60; 
              log_event(ups, LOG_ERR,  "apcserver: accept error. ERR=%s",
--- ./src/lib/apclibnis.c	Sat Aug  3 18:49:45 2002
+++ ./apcupsd-3.10.11-debug3/src/lib/apclibnis.c	
Fri Feb  6 21:38:58 2004
@@ -71,12 +71,50 @@
 
 static int read_nbytes(int fd, char *ptr, int nbytes)
 {
-    int nleft, nread;
-       
+    int nleft, nread, rc;
+    
+#if defined HAVE_PTHREADS && (defined HAVE_OPENBSD_OS || defined HAVE_FREEBSD_OS)
+    fd_set fds;
+#endif
+
     nleft = nbytes;
-    errno = 0;
+
     while (nleft > 0) {
+
 	do {
+
+#if defined HAVE_PTHREADS && (defined HAVE_OPENBSD_OS || defined HAVE_FREEBSD_OS)
+            /* 
+	     * Work around a bug in OpenBSD & FreeBSD userspace pthreads
+	     * implementations.
+	     *
+	     * The pthreads implementation under the hood sets O_NONBLOCK
+	     * implicitly on all fds. This setting is not visible to the user
+	     * application but is relied upon by the pthreads library to prevent
+	     * blocking syscalls in one thread from halting all threads in the
+	     * process. When a process exit()s or exec()s, the implicit
+	     * O_NONBLOCK flags are removed from all fds, EVEN THOSE IT INHERITED.
+	     * If another process is still using the inherited fds, there will
+	     * soon be trouble.
+	     *
+	     * apcupsd is bitten by this issue after fork()ing a child process to
+	     * run apccontrol.
+	     *
+	     * select() is conveniently immune to the O_NONBLOCK issue so we use
+	     * that to make sure the following read() will not block.
+	     */
+	    do {
+		FD_ZERO(&fds);
+		FD_SET(fd, &fds);
+		rc = select(fd+1, &fds, NULL, NULL, NULL);
+	    } while (rc == -1 && (errno == EINTR || errno == EAGAIN));
+	    if (rc < 0)
+	    {
+		net_errno = errno;
+		return(-1);		 /* error */
+	    }
+#endif
+
 	    nread = read(fd, ptr, nleft);    
 	} while (nread == -1 && (errno == EINTR || errno == EAGAIN));
 	if (nread <= 0) {
@@ -100,6 +138,15 @@
 
     nleft = nbytes;
     while (nleft > 0) {
+#if defined HAVE_PTHREADS && (defined HAVE_OPENBSD_OS || defined HAVE_FREEBSD_OS)
+	/* 
+	 * Work around a bug in OpenBSD & FreeBSD userspace pthreads
+	 * implementations. Rationale is the same as described above.
+	 * This seemingly-pointless fcntl() call causes the pthreads
+	 * library to reapply the O_NONBLOCK flag appropriately.
+	 */
+	fcntl(fd, F_SETFL, fcntl(fd, F_GETFL));
+#endif
 	nwritten = write(fd, ptr, nleft);
 	if (nwritten <= 0) {
 	    net_errno = errno;
@@ -225,6 +272,13 @@
 	return -1;
     }
     /* connect to server */
+#if defined HAVE_PTHREADS && (defined HAVE_OPENBSD_OS || defined HAVE_FREEBSD_OS)
+    /* 
+     * Work around a bug in OpenBSD & FreeBSD userspace pthreads
+     * implementations. Rationale is the same as described above.
+     */
+    fcntl(sockfd, F_SETFL, fcntl(sockfd, F_GETFL));
+#endif
     if (connect(sockfd, (struct sockaddr *) &tcp_serv_addr, sizeof(tcp_serv_addr)) < 0) {
         sprintf(net_errbuf, "tcp_open: cannot connect to server %s on port %d.\n\
 ERR=%s\n", host, port, strerror(errno));
@@ -243,6 +297,50 @@
     close(sockfd);
 }
  
+/*     
+ * Accept a TCP connection.
+ * Returns -1 on error.
+ * Returns file descriptor of new connection otherwise.
+ */
+int net_accept(int fd, struct sockaddr_in *cli_addr)
+{
+    socklen_t clilen = sizeof(*cli_addr);
+    int newfd, rc;
+
+#if defined HAVE_PTHREADS && (defined HAVE_OPENBSD_OS || defined HAVE_FREEBSD_OS)
+    fd_set fds;
+#endif
+
+    do {
+
+#if defined HAVE_PTHREADS && (defined HAVE_OPENBSD_OS || defined HAVE_FREEBSD_OS)
+	/*
+	 * Work around a bug in OpenBSD & FreeBSD userspace pthreads
+	 * implementations. Rationale is the same as described above.
+	 */
+	do {
+	    FD_ZERO(&fds);
+	    FD_SET(fd, &fds);
+	    rc = select(fd+1, &fds, NULL, NULL, NULL);
+	} while (rc == -1 && (errno == EINTR || errno == EAGAIN));
+	if (rc < 0)
+	{
+	    net_errno = errno;
+	    return(-1);		 /* error */
+	}
+#endif
+
+	newfd = accept(fd, (struct sockaddr*)cli_addr, &clilen);
+    } while (newfd == -1 && (errno == EINTR || errno == EAGAIN));
+    
+    if (newfd < 0)
+    {
+	net_errno = errno;
+        return(-1);		 /* error */
+    }
+
+    return newfd;
+}
 
 int	upserror, syserrno;
 
--- ./include/apc_nis.h	Tue May 28 09:34:24 2002
+++ ./apcupsd-3.10.11-debug3/include/apc_nis.h	
Fri Feb  6 21:19:14 2004
@@ -40,4 +40,7 @@
 /* Close the network connection */
 void net_close(int sockfd);
 
+/* Wait for and accept a new TCP connection */
+int net_accept(int fd, struct sockaddr_in *cli_addr);
+
 extern int  upserror, syserrno;