Make sure to set file permission before capabilitiesHEADmaster

1 files changed, 71 insertions, 50 deletions

diff --git a/main.c b/main.c
index bca38fc..8d0c1a3 100644
--- a/main.c
+++ b/main.c
@@ -5,6 +5,7 @@
 #include <limits.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <stdbool.h>
 #include <sys/stat.h>
 #include <sys/sendfile.h>
 #include <sys/capability.h>
@@ -13,45 +14,45 @@
 #define GSR_KMS_SERVER_FILEPATH "/var/lib/flatpak/app/com.dec05eba.gpu_screen_recorder/current/active/files/bin/gsr-kms-server"
 #define GSR_GLOBAL_HOTKEYS_FILEPATH "/var/lib/flatpak/app/com.dec05eba.gpu_screen_recorder/current/active/files/bin/gsr-global-hotkeys"
 
-static int readlink_realpath(const char *filepath, char *buffer) {
+static bool readlink_realpath(const char *filepath, char *buffer) {
     char symlinked_path[PATH_MAX];
     ssize_t bytes_written = readlink(filepath, symlinked_path, sizeof(symlinked_path) - 1);
     if(bytes_written == -1 && errno == EINVAL) {
         /* Not a symlink */
         strncpy(symlinked_path, filepath, sizeof(symlinked_path));
     } else if(bytes_written == -1) {
-        return 0;
+        return false;
     } else {
         symlinked_path[bytes_written] = '\0';
     }
 
     if(!realpath(symlinked_path, buffer))
-        return 0;
+        return false;
 
-    return 1;
+    return true;
 }
 
-static int file_has_sys_admin_capability(const char *filepath) {
+static bool file_has_sys_admin_capability(const char *filepath) {
     cap_t cap = cap_get_file(filepath);
     if(!cap)
-        return 0;
+        return false;
 
     cap_flag_value_t res = CAP_CLEAR;
     cap_get_flag(cap, CAP_SYS_ADMIN, CAP_PERMITTED, &res);
-    int cap_set = res == CAP_SET;
+    bool cap_set = res == CAP_SET;
     cap_free(cap);
     return cap_set;
 }
 
-static int file_set_capabilities(const char *filepath, const cap_value_t *caps_to_set, int num_caps_to_set) {
+static bool file_set_capabilities(const char *filepath, const cap_value_t *caps_to_set, int num_caps_to_set) {
     cap_t cap = cap_get_file(filepath);
     if(!cap && errno != ENODATA)
-        return 0;
+        return false;
 
     if(!cap) {
         cap = cap_init();
         if(!cap)
-            return 0;
+            return false;
     }
 
     int res = 0;
@@ -63,7 +64,11 @@ static int file_set_capabilities(const char *filepath, const cap_value_t *caps_t
     return res == 0;
 }
 
-static int create_local_kms_server_proxy_directory(const char *home) {
+static bool file_set_permissions(const char *filepath, unsigned int permissions) {
+    return chmod(filepath, permissions) == 0;
+}
+
+static bool create_local_kms_server_proxy_directory(const char *home) {
     char path[PATH_MAX];
     int err;
 
@@ -73,16 +78,16 @@ static int create_local_kms_server_proxy_directory(const char *home) {
         snprintf(path, sizeof(path), "%s/%s", home, path_part);
         err = mkdir(path, S_IRWXU);
         if(err == -1 && errno != EEXIST)
-            return 0;
+            return false;
     }
 
-    return 1;
+    return true;
 }
 
-static int copy_file_atomic(const char *source_path, const char *dest_path) {
+static bool copy_file_atomic(const char *source_path, const char *dest_path) {
     int in_fd = -1;
     int out_fd = -1;
-    int res = 0;
+    bool res = false;
     char tmp_filepath[PATH_MAX];
     snprintf(tmp_filepath, sizeof(tmp_filepath), "%s.tmp", dest_path);
 
@@ -101,7 +106,7 @@ static int copy_file_atomic(const char *source_path, const char *dest_path) {
     if(sendfile(out_fd, in_fd, NULL, st.st_size) != st.st_size)
         goto done;
 
-    res = 1;
+    res = true;
 
     done:
     if(in_fd)
@@ -122,6 +127,48 @@ static void usage(void) {
     exit(1);
 }
 
+static bool set_kms_server_proxy_permissions_and_capabilities(const char *kms_server_proxy_filepath) {
+    /* owner: read/write/execute, group: read/execute, public: read/execute */
+    if(!file_set_permissions(kms_server_proxy_filepath, 0755)) {
+        fprintf(stderr, "Error: failed to set kms-server-proxy permissions\n");
+        return false;
+    }
+
+    if(!file_set_capabilities(kms_server_proxy_filepath, (const cap_value_t[]){ CAP_SYS_ADMIN, CAP_SETFCAP, CAP_SETUID }, 3)) {
+        fprintf(stderr, "Error: failed to set kms-server-proxy capabilities\n");
+        return false;
+    }
+
+    return true;
+}
+
+/* |gsr_global_hotkeys_local_filepath| can be NULL */
+static bool setup_local_files(const char *user_homepath, const char *kms_server_proxy_local_filepath, const char *gsr_kms_server_local_filepath, const char *gsr_global_hotkeys_local_filepath) {
+    if(!create_local_kms_server_proxy_directory(user_homepath)) {
+        fprintf(stderr, "Error: failed to create ~/.local/share/gpu-screen-recorder directory\n");
+        return false;
+    }
+
+    if(!copy_file_atomic(KMS_SERVER_PROXY_FILEPATH, kms_server_proxy_local_filepath)) {
+        fprintf(stderr, "Error: failed to copy kms-server-proxy to %s\n", kms_server_proxy_local_filepath);
+        return false;
+    }
+
+    if(!copy_file_atomic(GSR_KMS_SERVER_FILEPATH, gsr_kms_server_local_filepath)) {
+        fprintf(stderr, "Error: failed to copy gsr-kms-server to %s\n", gsr_kms_server_local_filepath);
+        return false;
+    }
+
+    if(gsr_global_hotkeys_local_filepath) {
+        if(!copy_file_atomic(GSR_GLOBAL_HOTKEYS_FILEPATH, gsr_global_hotkeys_local_filepath)) {
+            fprintf(stderr, "Error: failed to copy gsr-global-hotkeys to %s\n", gsr_global_hotkeys_local_filepath);
+            return false;
+        }
+    }
+
+    return true;
+}
+
 static int setup_gsr_ui(const char *user_homepath) {
     char self_path[PATH_MAX];
     if(!readlink_realpath("/proc/self/exe", self_path)) {
@@ -146,29 +193,13 @@ static int setup_gsr_ui(const char *user_homepath) {
     snprintf(gsr_global_hotkeys_local_filepath, sizeof(gsr_global_hotkeys_local_filepath), "%s/.local/share/gpu-screen-recorder/gsr-global-hotkeys", user_homepath);
 
     if(geteuid() == 0) { /* is current user root? */
-        int success = 1;
-        success &= (file_set_capabilities(kms_server_proxy_local_filepath, (const cap_value_t[]){ CAP_SYS_ADMIN, CAP_SETFCAP, CAP_SETUID }, 3) == 1);
-        return success ? 0 : 1;
-    } else {
-        if(create_local_kms_server_proxy_directory(user_homepath) != 1) {
-            fprintf(stderr, "Error: failed to create ~/.local/share/gpu-screen-recorder directory\n");
-            return 1;
-        }
-
-        if(copy_file_atomic(KMS_SERVER_PROXY_FILEPATH, kms_server_proxy_local_filepath) != 1) {
-            fprintf(stderr, "Error: failed to copy kms-server-proxy to %s\n", kms_server_proxy_local_filepath);
+        if(!set_kms_server_proxy_permissions_and_capabilities(kms_server_proxy_local_filepath))
             return 1;
-        }
-
-        if(copy_file_atomic(GSR_KMS_SERVER_FILEPATH, gsr_kms_server_local_filepath) != 1) {
-            fprintf(stderr, "Error: failed to copy gsr-kms-server to %s\n", gsr_kms_server_local_filepath);
-            return 1;
-        }
 
-        if(copy_file_atomic(GSR_GLOBAL_HOTKEYS_FILEPATH, gsr_global_hotkeys_local_filepath) != 1) {
-            fprintf(stderr, "Error: failed to copy gsr-global-hotkeys to %s\n", gsr_global_hotkeys_local_filepath);
+        return 0;
+    } else {
+        if(!setup_local_files(user_homepath, kms_server_proxy_local_filepath, gsr_kms_server_local_filepath, gsr_global_hotkeys_local_filepath))
             return 1;
-        }
 
         const char *args[] = { "pkexec", kms_server_proxy_local_filepath, "setup-gsr-ui", user_homepath, NULL };
         return execvp(args[0], (char *const*)args);
@@ -209,24 +240,14 @@ static int launch_gsr_kms_server(const char *initial_socket_path, const char *ca
         const char *args[] = { "pkexec", gsr_kms_server_local_filepath, initial_socket_path, card_path, NULL };
         return execvp(args[0], (char *const*)args);
     } else if(geteuid() == 0) { /* is current user root? */
-        file_set_capabilities(kms_server_proxy_local_filepath, (const cap_value_t[]){ CAP_SYS_ADMIN, CAP_SETFCAP, CAP_SETUID }, 3);
+        if(!set_kms_server_proxy_permissions_and_capabilities(kms_server_proxy_local_filepath))
+            return 1;
+
         const char *args[] = { gsr_kms_server_local_filepath, initial_socket_path, card_path, NULL };
         return execv(args[0], (char *const*)args);
     } else {
-        if(create_local_kms_server_proxy_directory(user_homepath) != 1) {
-            fprintf(stderr, "Error: failed to create ~/.local/share/gpu-screen-recorder directory\n");
+        if(!setup_local_files(user_homepath, kms_server_proxy_local_filepath, gsr_kms_server_local_filepath, NULL))
             return 1;
-        }
-
-        if(copy_file_atomic(KMS_SERVER_PROXY_FILEPATH, kms_server_proxy_local_filepath) != 1) {
-            fprintf(stderr, "Error: failed to copy kms-server-proxy to %s\n", kms_server_proxy_local_filepath);
-            return 1;
-        }
-
-        if(copy_file_atomic(GSR_KMS_SERVER_FILEPATH, gsr_kms_server_local_filepath) != 1) {
-            fprintf(stderr, "Error: failed to copy gsr-kms-server to %s\n", gsr_kms_server_local_filepath);
-            return 1;
-        }
 
         const char *args[] = { "pkexec", kms_server_proxy_local_filepath, initial_socket_path, card_path, user_homepath, NULL };
         return execvp(args[0], (char *const*)args);