5 files changed, 105 insertions, 16 deletions

diff --git a/RELNOTES b/RELNOTES
index 33088dfe5..ccd841e27 100644
--- a/RELNOTES
+++ b/RELNOTES
@@ -34,6 +34,7 @@ firejail (0.9.46-rc1) baseline; urgency=low
   * feature: --fix-sound support in firecfg
   * feature: added support for sandboxing Xpra, Xvfb and Xephyr in 
     independent sandboxes when started with firejail --x11
+  * feature: support for Xpra extra params in firejail config file
   * new profiles: xiphos, Tor Browser Bundle, display (imagemagick), Wire,
   * new profiles: mumble, zoom, Guayadeque, qemu, keypass2, xed, pluma,
   * new profiles: Cryptocat, Bless, Gnome 2048, Gnome Calculator,
diff --git a/etc/firejail.config b/etc/firejail.config
index 537ac9b38..1db33edda 100644
--- a/etc/firejail.config
+++ b/etc/firejail.config
@@ -100,6 +100,10 @@
 # xephyr-extra-params -keybd ephyr,,,xkbmodel=evdev
 # xephyr-extra-params -grayscale
 
+# Xpra server command extra parameters. None by default; this is an example.
+# xpra-extra-params --dpi 96
+
+
 # Screen size for --x11=xvfb, default 800x600x24.  The third dimension is
 # color depth; use 24 unless you know exactly what you're doing.
 # xvfb-screen 640x480x24
diff --git a/src/firejail/checkcfg.c b/src/firejail/checkcfg.c
index 24d8d0381..3c0c1b9ac 100644
--- a/src/firejail/checkcfg.c
+++ b/src/firejail/checkcfg.c
@@ -27,6 +27,7 @@ static int initialized = 0;
 static int cfg_val[CFG_MAX];
 char *xephyr_screen = "800x600";
 char *xephyr_extra_params = "";
+char *xpra_extra_params = "";
 char *xvfb_screen = "800x600x24";
 char *xvfb_extra_params = "";
 char *netfilter_default = NULL;
@@ -248,14 +249,23 @@ int checkcfg(int val) {
                         }
                                 
                         // Xephyr command extra parameters
-                        else if (strncmp(ptr, "xephyr-extra-params ", 19) == 0) {
+                        else if (strncmp(ptr, "xephyr-extra-params ", 20) == 0) {
                                 if (*xephyr_extra_params != '\0')
                                         goto errout;
-                                xephyr_extra_params = strdup(ptr + 19);
+                                xephyr_extra_params = strdup(ptr + 20);
                                 if (!xephyr_extra_params)
                                         errExit("strdup");
                         }
                         
+                        // xpra server extra parameters
+                        else if (strncmp(ptr, "xpra-extra-params ", 18) == 0) {
+                                if (*xpra_extra_params != '\0')
+                                        goto errout;
+                                xpra_extra_params = strdup(ptr + 18);
+                                if (!xpra_extra_params)
+                                        errExit("strdup");
+                        }
+
                         // Xvfb screen size
                         else if (strncmp(ptr, "xvfb-screen ", 12) == 0) {
                                 // expecting three numbers separated by x's
diff --git a/src/firejail/firejail.h b/src/firejail/firejail.h
index 09fadcf34..6b1786a93 100644
--- a/src/firejail/firejail.h
+++ b/src/firejail/firejail.h
@@ -692,6 +692,7 @@ enum {
 };
 extern char *xephyr_screen;
 extern char *xephyr_extra_params;
+extern char *xpra_extra_params;
 extern char *xvfb_screen;
 extern char *xvfb_extra_params;
 extern char *netfilter_default;
diff --git a/src/firejail/x11.c b/src/firejail/x11.c
index da881f344..0f7ea56b6 100644
--- a/src/firejail/x11.c
+++ b/src/firejail/x11.c
@@ -239,8 +239,8 @@ void x11_start_xvfb(int argc, char **argv) {
 
         // parse xvfb_extra_params
         // very basic quoting support
-        char *temp = strdup(xephyr_extra_params);
-        if (*xephyr_extra_params != '\0') {
+        char *temp = strdup(xvfb_extra_params);
+        if (*xvfb_extra_params != '\0') {
                 if (!temp)
                         errExit("strdup");
                 bool dquote = false;
@@ -267,6 +267,7 @@ void x11_start_xvfb(int argc, char **argv) {
                         exit(1);
                 }
 
+                server_argv[pos++] = temp;
                 for (i = 0; i < (int) strlen(xvfb_extra_params)-1; i++) {
                         if (pos >= (sizeof(server_argv)/sizeof(*server_argv)) - 2) {
                                 fprintf(stderr, "Error: arg count limit exceeded while parsing xvfb_extra_params\n");
@@ -284,12 +285,12 @@ void x11_start_xvfb(int argc, char **argv) {
 
         if (arg_debug) {
                 size_t i = 0;
-                printf("xvfb server:");
+                printf("\n*** Starting xvfb server:");
                 while (server_argv[i]!=NULL) {
                         printf(" \"%s\"", server_argv[i]);
                         i++;
                 }
-                putchar('\n');
+                printf(" ***\n\n");
         }
 
         // remove --x11 arg
@@ -307,12 +308,12 @@ void x11_start_xvfb(int argc, char **argv) {
 
         if (arg_debug) {
                 size_t i = 0;
-                printf("xvfb client:");
+                printf("\n*** Stating xvfb client:");
                 while (jail_argv[i]!=NULL) {
                         printf(" \"%s\"", jail_argv[i]);
                         i++;
                 }
-                putchar('\n');
+                printf(" ***\n\n");
         }
 
         server = fork();
@@ -471,13 +472,18 @@ void x11_start_xephyr(int argc, char **argv) {
                         exit(1);
                 }
 
+                server_argv[pos++] = temp;
                 for (i = 0; i < (int) strlen(xephyr_extra_params)-1; i++) {
                         if (pos >= (sizeof(server_argv)/sizeof(*server_argv)) - 2) {
                                 fprintf(stderr, "Error: arg count limit exceeded while parsing xephyr_extra_params\n");
                                 exit(1);
                         }
-                        if (temp[i] == '\0' && (temp[i+1] == '\"' || temp[i+1] == '\'')) server_argv[pos++] = temp + i + 2;
-                        else if (temp[i] == '\0' && temp[i+1] != '\0') server_argv[pos++] = temp + i + 1;
+                        if (temp[i] == '\0' && (temp[i+1] == '\"' || temp[i+1] == '\'')) {
+                                server_argv[pos++] = temp + i + 2;
+                        }
+                        else if (temp[i] == '\0' && temp[i+1] != '\0') {
+                                server_argv[pos++] = temp + i + 1;
+                        }
                 }
         }
 
@@ -490,12 +496,12 @@ void x11_start_xephyr(int argc, char **argv) {
 
         if (arg_debug) {
                 size_t i = 0;
-                printf("xephyr server:");
+                printf("\n*** Starting xephyr server:");
                 while (server_argv[i]!=NULL) {
                         printf(" \"%s\"", server_argv[i]);
                         i++;
                 }
-                putchar('\n');
+                printf(" ***\n\n");
         }
 
         // remove --x11 arg
@@ -513,12 +519,12 @@ void x11_start_xephyr(int argc, char **argv) {
 
         if (arg_debug) {
                 size_t i = 0;
-                printf("xephyr client:");
+                printf("*** Starting xephyr client:");
                 while (jail_argv[i]!=NULL) {
                         printf(" \"%s\"", jail_argv[i]);
                         i++;
                 }
-                putchar('\n');
+                printf(" ***\n\n");
         }
 
         server = fork();
@@ -631,7 +637,74 @@ void x11_start_xpra(int argc, char **argv) {
                 errExit("asprintf");
 
         // build the start command
-        char *server_argv[] = { "xpra", "start", display_str, "--no-daemon",  NULL };
+        char *server_argv[256] = {                // rest initialyzed to NULL
+                 "xpra", "start", display_str, "--no-daemon", 
+        };
+        unsigned pos = 0;
+        while (server_argv[pos] != NULL) pos++;
+
+        assert(xpra_extra_params);                // should be "" if empty
+
+        // parse xephyr_extra_params
+        // very basic quoting support
+        char *temp = strdup(xpra_extra_params);
+        if (*xpra_extra_params != '\0') {
+                if (!temp)
+                        errExit("strdup");
+                bool dquote = false;
+                bool squote = false;
+                for (i = 0; i < (int) strlen(xpra_extra_params); i++) {
+                        if (temp[i] == '\"') {
+                                dquote = !dquote;
+                                                  // replace closing quote by \0
+                                if (dquote) temp[i] = '\0';
+                        }
+                        if (temp[i] == '\'') {
+                                squote = !squote;
+                                                  // replace closing quote by \0
+                                if (squote) temp[i] = '\0';
+                        }
+                        if (!dquote && !squote && temp[i] == ' ') temp[i] = '\0';
+                        if (dquote && squote) {
+                                fprintf(stderr, "Error: mixed quoting found while parsing xpra_extra_params\n");
+                                exit(1);
+                        }
+                }
+                if (dquote) {
+                        fprintf(stderr, "Error: unclosed quote found while parsing xpra_extra_params\n");
+                        exit(1);
+                }
+
+                server_argv[pos++] = temp;
+                for (i = 0; i < (int) strlen(xpra_extra_params)-1; i++) {
+                        if (pos >= (sizeof(server_argv)/sizeof(*server_argv)) - 2) {
+                                fprintf(stderr, "Error: arg count limit exceeded while parsing xpra_extra_params\n");
+                                exit(1);
+                        }
+                        if (temp[i] == '\0' && (temp[i+1] == '\"' || temp[i+1] == '\'')) {
+                                server_argv[pos++] = temp + i + 2;
+                        }
+                        else if (temp[i] == '\0' && temp[i+1] != '\0') {
+                                server_argv[pos++] = temp + i + 1;
+                        }
+                }
+        }
+
+        server_argv[pos++] = NULL;
+
+                                                  // no overrun
+        assert(pos < (sizeof(server_argv)/sizeof(*server_argv)));
+        assert(server_argv[pos-1] == NULL);       // last element is null
+        
+        if (arg_debug) {
+                size_t i = 0;
+                printf("\n*** Starting xpra server: ");
+                while (server_argv[i]!=NULL) {
+                        printf(" \"%s\"", server_argv[i]);
+                        i++;
+                }
+                printf(" ***\n\n");
+        }
 
         int fd_null = -1;
         if (arg_quiet) {
@@ -716,7 +789,7 @@ void x11_start_xpra(int argc, char **argv) {
 
         // build jail command
         char *firejail_argv[argc+2];
-        int pos = 0;
+        pos = 0;
         for (i = 0; i < argc; i++) {
                 if (strncmp(argv[i], "--x11", 5) == 0)
                         continue;