Log client process name alongside pid if possible on accept and disconnect

This helps identifing a problematic client software much quicker.

1 files changed, 44 insertions, 5 deletions

diff --git a/src/client.c b/src/client.c
index 85d0c8b..1588c38 100644
--- a/src/client.c
+++ b/src/client.c
@@ -78,6 +78,27 @@ static struct collection client_list;
 pthread_mutex_t client_list_mutex;
 static uint32_t client_number = 0;
 
+#ifdef SO_PEERCRED
+static char* _get_process_name_by_pid(const int pid)
+{
+        char* name = (char*)calloc(1024, sizeof(char));
+        if(name) {
+                sprintf(name, "/proc/%d/cmdline", pid);
+                FILE* f = fopen(name, "r");
+                if(f) {
+                        size_t size;
+                        size = fread(name, sizeof(char), 1024, f);
+                        if(size > 0) {
+                                if('\n' == name[size-1])
+                                        name[size-1]='\0';
+                        }
+                        fclose(f);
+                }
+        }
+        return name;
+}
+#endif
+
 /**
  * Receive raw data from the client socket.
  *
@@ -212,23 +233,41 @@ int client_accept(int listenfd)
         if (log_level >= LL_INFO) {
                 struct ucred cr;
                 len = sizeof(struct ucred);
-                getsockopt(cfd, SOL_SOCKET, SO_PEERCRED, &cr, &len);
+                getsockopt(client->fd, SOL_SOCKET, SO_PEERCRED, &cr, &len);
 
                 if (getpid() == cr.pid) {
-                        usbmuxd_log(LL_INFO, "New client on fd %d (self)", client->fd);
+                        usbmuxd_log(LL_INFO, "Client %d accepted: %s[%d]", client->fd, PACKAGE_NAME, cr.pid);
                 } else {
-                        usbmuxd_log(LL_INFO, "New client on fd %d (pid %d)", client->fd, cr.pid);
+                        char* process_name = _get_process_name_by_pid(cr.pid);
+                        usbmuxd_log(LL_INFO, "Client %d accepted: %s[%d]", client->fd, process_name, cr.pid);
+                        free(process_name);
                 }
         }
 #else
-        usbmuxd_log(LL_INFO, "New client on fd %d", client->fd);
+        usbmuxd_log(LL_INFO, "Client %d accepted", client->fd);
 #endif
         return client->fd;
 }
 
 void client_close(struct mux_client *client)
 {
-        usbmuxd_log(LL_INFO, "Disconnecting client fd %d", client->fd);
+#ifdef SO_PEERCRED
+        if (log_level >= LL_INFO) {
+                struct ucred cr;
+                socklen_t len = sizeof(struct ucred);
+                getsockopt(client->fd, SOL_SOCKET, SO_PEERCRED, &cr, &len);
+
+                if (getpid() == cr.pid) {
+                        usbmuxd_log(LL_INFO, "Client %d is going to be disconnected: %s[%d]", client->fd, PACKAGE_NAME, cr.pid);
+                } else {
+                        char* process_name = _get_process_name_by_pid(cr.pid);
+                        usbmuxd_log(LL_INFO, "Client %d is going to be disconnected: %s[%d]", client->fd, process_name, cr.pid);
+                        free(process_name);
+                }
+        }
+#else
+        usbmuxd_log(LL_INFO, "Client %d is going to be disconnected", client->fd);
+#endif
         if(client->state == CLIENT_CONNECTING1 || client->state == CLIENT_CONNECTING2) {
                 usbmuxd_log(LL_INFO, "Client died mid-connect, aborting device %d connection", client->connect_device);
                 client->state = CLIENT_DEAD;