wpa_cli: Add option to use child process to receive events

CFLAGS += -DCONFIG_WPA_CLI_FORK=y in .config can be used to
configure wpa_cli build to make a version of wpa_cli that forks
a child process to receive event messages. This allows the events
to be shown immediately instead of having to wait for the next
periodic poll with PING.

diff --git a/wpa_supplicant/wpa_cli.c b/wpa_supplicant/wpa_cli.c
index 272c20e59168b00314a898402602b8e58d3d584b..6cd9c6890768e71b6b35a80cbd2bb86c72fcace3 100644 (file)
--- a/wpa_supplicant/wpa_cli.c
+++ b/wpa_supplicant/wpa_cli.c
@@ -23,6 +23,9 @@
 #include <readline/readline.h>
 #include <readline/history.h>
 #endif /* CONFIG_READLINE */
+#ifdef CONFIG_WPA_CLI_FORK
+#include <sys/wait.h>
+#endif /* CONFIG_WPA_CLI_FORK */
 
 #include "common/wpa_ctrl.h"
 #include "common.h"
@@ -88,6 +91,9 @@ static const char *wpa_cli_full_license =
 
 static struct wpa_ctrl *ctrl_conn;
 static struct wpa_ctrl *mon_conn;
+#ifdef CONFIG_WPA_CLI_FORK
+static pid_t mon_pid = 0;
+#endif /* CONFIG_WPA_CLI_FORK */
 static int wpa_cli_quit = 0;
 static int wpa_cli_attached = 0;
 static int wpa_cli_connected = 0;
@@ -121,6 +127,41 @@ static void usage(void)
 }
 
 
+#ifdef CONFIG_WPA_CLI_FORK
+static void wpa_cli_monitor(void)
+{
+       char buf[256];
+       size_t len = sizeof(buf) - 1;
+       struct timeval tv;
+       fd_set rfds;
+
+       while (mon_conn) {
+               int s = wpa_ctrl_get_fd(mon_conn);
+               tv.tv_sec = 5;
+               tv.tv_usec = 0;
+               FD_ZERO(&rfds);
+               FD_SET(s, &rfds);
+               if (select(s + 1, &rfds, NULL, NULL, &tv) < 0) {
+                       perror("select");
+                       break;
+               }
+               if (mon_conn == NULL)
+                       break;
+               if (FD_ISSET(s, &rfds)) {
+                       len = sizeof(buf) - 1;
+                       int res = wpa_ctrl_recv(mon_conn, buf, &len);
+                       if (res < 0) {
+                               perror("wpa_ctrl_recv");
+                               break;
+                       }
+                       buf[len] = '\0';
+                       printf("%s\n", buf);
+               }
+       }
+}
+#endif /* CONFIG_WPA_CLI_FORK */
+
+
 static int wpa_cli_open_connection(const char *ifname, int attach)
 {
 #if defined(CONFIG_CTRL_IFACE_UDP) || defined(CONFIG_CTRL_IFACE_NAMED_PIPE)
@@ -170,6 +211,21 @@ static int wpa_cli_open_connection(const char *ifname, int attach)
                               "wpa_supplicant.\n");
                        return -1;
                }
+
+#ifdef CONFIG_WPA_CLI_FORK
+               {
+                       pid_t p = fork();
+                       if (p < 0) {
+                               perror("fork");
+                               return -1;
+                       }
+                       if (p == 0) {
+                               wpa_cli_monitor();
+                               exit(0);
+                       } else
+                               mon_pid = p;
+               }
+#endif /* CONFIG_WPA_CLI_FORK */
        }
 
        return 0;
@@ -191,6 +247,14 @@ static void wpa_cli_close_connection(void)
                wpa_ctrl_close(mon_conn);
                mon_conn = NULL;
        }
+#ifdef CONFIG_WPA_CLI_FORK
+       if (mon_pid) {
+               int status;
+               kill(mon_pid, SIGPIPE);
+               wait(&status);
+               mon_pid = 0;
+       }
+#endif /* CONFIG_WPA_CLI_FORK */
 }