Add support for writing the PID to a file in server mode.

This is specified with the -I or --pidfile option.

Issue:		120 (PID file support)

RELEASE_NOTES

@@ -1,5 +1,8 @@
 == iperf 3.?.? ????-??-?? ==
   * Setting CPU affinity now works on FreeBSD.
+  * Added -I flag for server to write a PID file, mostly useful for
+    daemon mode.
+  * Bug fixes.
 
 == iperf 3.0.1 2014-01-10 ==
   * Added the following new flags

src/iperf.h

@@ -172,6 +172,7 @@ struct iperf_test
 #endif
     char     *title;				/* -T option */
     char     *congestion;			/* -C option */
+    char     *pidfile;				/* -P option */
 
     int       ctrl_sck;
     int       listener;

src/iperf3.1

@@ -69,6 +69,9 @@ run in server mode
 .TP
 .BR -D ", " --daemon " "
 run the server in background as a daemon
+.TP
+.BR -I ", " --pidfile " \fIfile\fR"
+write a file with the process ID, most useful when running as a daemon.
 
 .SH "CLIENT SPECIFIC OPTIONS"
 .TP

src/iperf_api.c

@@ -545,6 +545,7 @@ iperf_parse_arguments(struct iperf_test *test, int argc, char **argv)
 #if defined(linux) && defined(TCP_CONGESTION)
         {"linux-congestion", required_argument, NULL, 'C'},
 #endif
+	{"pidfile", required_argument, NULL, 'I'},
         {"debug", no_argument, NULL, 'd'},
         {"help", no_argument, NULL, 'h'},
         {NULL, 0, NULL, 0}
@@ -559,7 +560,7 @@ iperf_parse_arguments(struct iperf_test *test, int argc, char **argv)
 
     blksize = 0;
     server_flag = client_flag = rate_flag = duration_flag = 0;
-    while ((flag = getopt_long(argc, argv, "p:f:i:DVJvsc:ub:t:n:k:l:P:Rw:B:M:N46S:L:ZO:F:A:T:C:dh", longopts, NULL)) != -1) {
+    while ((flag = getopt_long(argc, argv, "p:f:i:DVJvsc:ub:t:n:k:l:P:Rw:B:M:N46S:L:ZO:F:A:T:C:dI:h", longopts, NULL)) != -1) {
         switch (flag) {
             case 'p':
                 test->server_port = atoi(optarg);
@@ -762,6 +763,10 @@ iperf_parse_arguments(struct iperf_test *test, int argc, char **argv)
 	    case 'd':
 		test->debug = 1;
 		break;
+	    case 'I':
+		test->pidfile = strdup(optarg);
+		server_flag = 1;
+	        break;
             case 'h':
             default:
                 usage_long();
@@ -2383,6 +2388,39 @@ iperf_got_sigend(struct iperf_test *test)
     iperf_errexit(test, "interrupt - %s", iperf_strerror(i_errno));
 }
 
+/* Try to write a PID file if requested, return -1 on an error. */
+int
+iperf_create_pidfile(struct iperf_test *test)
+{
+    if (test->pidfile) {
+	int fd;
+	char buf[8];
+	fd = open(test->pidfile, O_WRONLY | O_CREAT | O_TRUNC, 0666);
+	if (fd < 0) {
+	    return -1;
+	}
+	snprintf(buf, sizeof(buf), "%d", getpid()); /* no trailing newline */
+	if (write(fd, buf, strlen(buf) + 1) < 0) {
+	    return -1;
+	}
+	if (close(fd) < 0) {
+	    return -1;
+	};
+    }
+    return 0;
+}
+
+/* Get rid of a PID file, return -1 on error. */
+int
+iperf_delete_pidfile(struct iperf_test *test)
+{
+    if (test->pidfile) {
+	if (unlink(test->pidfile) < 0) {
+	    return -1;
+	}
+    }
+    return 0;
+}
 
 int
 iperf_json_start(struct iperf_test *test)

src/iperf_api.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009-2013, The Regents of the University of California,
+ * Copyright (c) 2009-2014, The Regents of the University of California,
  * through Lawrence Berkeley National Laboratory (subject to receipt of any
  * required approvals from the U.S. Dept. of Energy).  All rights reserved.
  *
@@ -207,6 +207,8 @@ int iperf_server_listen(struct iperf_test *);
 int iperf_accept(struct iperf_test *);
 int iperf_handle_message_server(struct iperf_test *);
 void iperf_test_reset(struct iperf_test *);
+int iperf_create_pidfile(struct iperf_test *);
+int iperf_delete_pidfile(struct iperf_test *);
 
 /* JSON output routines. */
 int iperf_json_start(struct iperf_test *);
@@ -280,6 +282,7 @@ enum {
     IEAFFINITY = 132,       // Unable to set CPU affinity (check perror)
     IEDAEMON = 133,	    // Unable to become a daemon process
     IESETCONGESTION = 134,  // Unable to set TCP_CONGESTION
+    IEPIDFILE = 135,	    // Unable to write PID file
     /* Stream errors */
     IECREATESTREAM = 200,   // Unable to create a new stream (check herror/perror)
     IEINITSTREAM = 201,     // Unable to initialize stream (check herror/perror)

src/iperf_error.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009-2013, The Regents of the University of California,
+ * Copyright (c) 2009-2014, The Regents of the University of California,
  * through Lawrence Berkeley National Laboratory (subject to receipt of any
  * required approvals from the U.S. Dept. of Energy).  All rights reserved.
  *
@@ -47,6 +47,7 @@ iperf_errexit(struct iperf_test *test, const char *format, ...)
     } else
 	fprintf(stderr, "iperf3: %s\n", str);
     va_end(argp);
+    iperf_delete_pidfile(test);
     exit(1);
 }
 
@@ -294,6 +295,10 @@ iperf_strerror(int i_errno)
             snprintf(errstr, len, "unable to set TCP_CONGESTION: " 
                                   "Supplied congestion control algorithm not supported on this host");
             break;
+	case IEPIDFILE:
+            snprintf(errstr, len, "unable to write PID file");
+            perr = 1;
+            break;
     }
 
     if (herr || perr)

src/locale.c

@@ -84,6 +84,7 @@ const char usage_longstr[] = "Usage: iperf [-s|-c host] [options]\n"
                            "Server specific:\n"
                            "  -s, --server              run in server mode\n"
                            "  -D, --daemon              run the server as a daemon\n"
+                           "  -I, --pidfile file        write PID file\n"
                            "Client specific:\n"
                            "  -c, --client    <host>    run in client mode, connecting to <host>\n"
                            "  -u, --udp                 use UDP rather than TCP\n"

src/main.c

@@ -112,6 +112,10 @@ run(struct iperf_test *test)
 		}
 	    }
 	    consecutive_errors = 0;
+	    if (iperf_create_pidfile(test) < 0) {
+		i_errno = IEPIDFILE;
+		iperf_errexit(test, "error - %s", iperf_strerror(i_errno));
+	    }
             for (;;) {
                 if (iperf_run_server(test) < 0) {
 		    iperf_err(test, "error - %s", iperf_strerror(i_errno));
@@ -125,6 +129,7 @@ run(struct iperf_test *test)
 		    consecutive_errors = 0;
                 iperf_reset_test(test);
             }
+	    iperf_delete_pidfile(test);
             break;
         case 'c':
             if (iperf_run_client(test) < 0)