--x11=xpra rewrite

1 files changed, 66 insertions, 52 deletions

diff --git a/src/firejail/x11.c b/src/firejail/x11.c
index 9e818ab67..58908e9df 100644
--- a/src/firejail/x11.c
+++ b/src/firejail/x11.c
@@ -352,7 +352,7 @@ void x11_start_xephyr(int argc, char **argv) {
 
 void x11_start_xpra(int argc, char **argv) {
         EUID_ASSERT();
-        int i;
+        size_t i;
         struct stat s;
         pid_t client = 0;
         pid_t server = 0;
@@ -374,40 +374,14 @@ void x11_start_xpra(int argc, char **argv) {
         }
         
         int display = random_display_number();
+        char *display_str;
+        if (asprintf(&display_str, ":%d", display) == -1)
+                errExit("asprintf");
 
         // build the start command
-        int len = 50; // xpra start...
-        for (i = 0; i < argc; i++) {
-                len += strlen(argv[i]) + 1; // + ' '
-        }
-        
-        char *cmd1 = malloc(len + 1); // + '\0'
-        if (!cmd1)
-                errExit("malloc");
-        
-        sprintf(cmd1, "xpra start :%d --exit-with-children --start-child=\"", display);
-        char *ptr = cmd1 + strlen(cmd1);
-        for (i = 0; i < argc; i++) {
-                if (strcmp(argv[i], "--x11") == 0)
-                        continue;
-                if (strcmp(argv[i], "--x11=xpra") == 0)
-                        continue;
-                if (strcmp(argv[i], "--x11=xephyr") == 0)
-                        continue;
-                ptr += sprintf(ptr, "%s ", argv[i]);
-        }
-        sprintf(ptr, "\"");
-        if (arg_debug)
-                printf("xpra server: %s\n", cmd1);      
-        
-        // build the attach command
-        char *cmd2;
-        if (asprintf(&cmd2, "xpra --title=\"firejail x11 sandbox\" attach :%d", display) == -1)
-                errExit("asprintf");
-        if (arg_debug)
-                printf("xpra client: %s\n", cmd2);
+        char *server_argv[] = { "xpra", "start", display_str, "--no-daemon",  NULL };
 
-        signal(SIGHUP,SIG_IGN); // fix sleep(1) below
+        // start
         server = fork();
         if (server < 0)
                 errExit("fork");
@@ -415,13 +389,7 @@ void x11_start_xpra(int argc, char **argv) {
                 if (arg_debug)
                         printf("Starting xpra...\n");
         
-                char *a[4];
-                a[0] = "/bin/bash";
-                a[1] = "-c";
-                a[2] = cmd1;
-                a[3] = NULL;
-        
-                execvp(a[0], a); 
+                execvp(server_argv[0], server_argv);
                 perror("execvp");
                 exit(1);
         }
@@ -437,13 +405,13 @@ void x11_start_xpra(int argc, char **argv) {
                 if (stat(fname, &s) == 0)
                         break;
         };
+//      sleep(1);
         
         if (n == 10) {
                 fprintf(stderr, "Error: failed to start xpra\n");
                 exit(1);
         }
         free(fname);
-        sleep(1);
         
         if (arg_debug) {
                 printf("X11 sockets: "); fflush(0);
@@ -451,28 +419,74 @@ void x11_start_xpra(int argc, char **argv) {
                 (void) rv;
         }
 
+        // build attach command
+        char *attach_argv[] = { "xpra", "--title=\"firejail x11 sandbox\"", "attach", display_str };
+
         // run attach command
         client = fork();
         if (client < 0)
                 errExit("fork");
         if (client == 0) {
                 printf("\n*** Attaching to xpra display %d ***\n\n", display);
-                char *a[4];
-                a[0] = "/bin/bash";
-                a[1] = "-c";
-                a[2] = cmd2;
-                a[3] = NULL;
-        
-                execvp(a[0], a); 
+                execvp(attach_argv[0], attach_argv);
                 perror("execvp");
                 exit(1);
         }
-        sleep(1);
-        
-        if (!arg_quiet)
-                printf("Xpra server pid %d, client pid %d\n", server, client);
 
-        exit(0);
+        setenv("DISPLAY", display_str, 1);
+
+        // build jail command
+        char *firejail_argv[argc+2];
+        unsigned pos = 0;
+        for (i = 0; i < argc; i++) {
+                if (strcmp(argv[i], "--x11") == 0)
+                        continue;
+                if (strcmp(argv[i], "--x11=xpra") == 0)
+                        continue;
+                if (strcmp(argv[i], "--x11=xephyr") == 0)
+                        continue;
+                firejail_argv[pos] = argv[i];
+                pos++;
+        }
+        firejail_argv[pos] = NULL;
+
+        assert(pos < argc+2);
+        assert(!firejail_argv[pos]);
+
+        // start jail
+        pid_t jail = fork();
+        if (jail < 0)
+                errExit("fork");
+        if (jail == 0) {
+                execvp(firejail_argv[0], firejail_argv);
+                perror("execvp");
+                exit(1);
+        }
+
+        if (!arg_quiet)
+                printf("Xpra server pid %d, xpra client pid %d, jail %d\n", server, client, jail);
+
+        // wait for jail or server to end
+        while (1) {
+                pid_t pid = wait();
+
+                if (pid == jail) {
+                        sleep(3); // FIXME: find better way to wait for xpra
+                        char *stop_argv[] = { "xpra", "stop", display_str, NULL };
+                        pid_t stop = fork();
+                        if (stop < 0)
+                                errExit("fork");
+                        if (stop == 0) {
+                                execvp(stop_argv[0], stop_argv);
+                                perror("execvp");
+                                exit(1);
+                        }
+                        sleep(3);
+                        kill(client, SIGTERM);
+                        kill(server, SIGTERM);
+                        exit(0);
+                }
+        }
 }
 
 void x11_start(int argc, char **argv) {