1 files changed, 56 insertions, 27 deletions

diff --git a/kms/client/kms_client.c b/kms/client/kms_client.c
index 468e3a6..9fadf05 100644
--- a/kms/client/kms_client.c
+++ b/kms/client/kms_client.c
@@ -1,4 +1,5 @@
 #include "kms_client.h"
+#include "../../include/utils.h"
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
@@ -12,7 +13,6 @@
 #include <sys/wait.h>
 #include <sys/stat.h>
 #include <sys/capability.h>
-#include <sys/random.h>
 
 #define GSR_SOCKET_PAIR_LOCAL  0
 #define GSR_SOCKET_PAIR_REMOTE 1
@@ -20,21 +20,6 @@
 static void cleanup_socket(gsr_kms_client *self, bool kill_server);
 static int gsr_kms_client_replace_connection(gsr_kms_client *self);
 
-static bool generate_random_characters(char *buffer, int buffer_size, const char *alphabet, size_t alphabet_size) {
-    /* TODO: Use other functions on other platforms than linux */
-    if(getrandom(buffer, buffer_size, 0) < buffer_size) {
-        fprintf(stderr, "Failed to get random bytes, error: %s\n", strerror(errno));
-        return false;
-    }
-
-    for(int i = 0; i < buffer_size; ++i) {
-        unsigned char c = *(unsigned char*)&buffer[i];
-        buffer[i] = alphabet[c % alphabet_size];
-    }
-
-    return true;
-}
-
 static void close_fds(gsr_kms_response *response) {
     for(int i = 0; i < response->num_items; ++i) {
         for(int j = 0; j < response->items[i].num_dma_bufs; ++j) {
@@ -139,20 +124,48 @@ static bool create_socket_path(char *output_path, size_t output_path_size) {
 
     char random_characters[11];
     random_characters[10] = '\0';
-    if(!generate_random_characters(random_characters, 10, "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789", 62))
+    if(!generate_random_characters_standard_alphabet(random_characters, 10))
         return false;
 
     snprintf(output_path, output_path_size, "%s/.gsr-kms-socket-%s", home, random_characters);
     return true;
 }
 
-static void string_copy(char *dst, const char *src, int len) {
-    int src_len = strlen(src);
-    int min_len = src_len;
-    if(len - 1 < min_len)
-        min_len = len - 1;
-    memcpy(dst, src, min_len);
-    dst[min_len] = '\0';
+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 */
+        snprintf(symlinked_path, sizeof(symlinked_path), "%s", filepath);
+    } else if(bytes_written == -1) {
+        return false;
+    } else {
+        symlinked_path[bytes_written] = '\0';
+    }
+
+    if(!realpath(symlinked_path, buffer))
+        return false;
+
+    return true;
+}
+
+static bool strcat_safe(char *str, int size, const char *str_to_add) {
+    const int str_len = strlen(str);
+    const int str_to_add_len = strlen(str_to_add);
+    if(str_len + str_to_add_len + 1 >= size)
+        return false;
+
+    memcpy(str + str_len, str_to_add, str_to_add_len);
+    str[str_len + str_to_add_len] = '\0';
+    return true;
+}
+
+static void file_get_directory(char *filepath) {
+    char *end = strrchr(filepath, '/');
+    if(end == NULL)
+        filepath[0] = '\0';
+    else
+        *end = '\0';
 }
 
 static bool find_program_in_path(const char *program_name, char *filepath, int filepath_len) {
@@ -206,10 +219,26 @@ int gsr_kms_client_init(gsr_kms_client *self, const char *card_path) {
     }
 
     char server_filepath[PATH_MAX];
-    if(!find_program_in_path("gsr-kms-server", server_filepath, sizeof(server_filepath))) {
-        fprintf(stderr, "gsr error: gsr_kms_client_init: gsr-kms-server is not installed\n");
+    if(!readlink_realpath("/proc/self/exe", server_filepath)) {
+        fprintf(stderr, "gsr error: gsr_kms_client_init: failed to resolve /proc/self/exe\n");
         return -1;
     }
+    file_get_directory(server_filepath);
+
+    if(!strcat_safe(server_filepath, sizeof(server_filepath), "/gsr-kms-server")) {
+        fprintf(stderr, "gsr error: gsr_kms_client_init: gsr-kms-server path too long\n");
+        return -1;
+    }
+
+    if(access(server_filepath, F_OK) != 0) {
+        fprintf(stderr, "gsr info: gsr_kms_client_init: gsr-kms-server is not installed in the same directory as gpu-screen-recorder (%s not found), looking for gsr-kms-server in PATH instead\n", server_filepath);
+        if(!find_program_in_path("gsr-kms-server", server_filepath, sizeof(server_filepath)) || access(server_filepath, F_OK) != 0) {
+            fprintf(stderr, "gsr error: gsr_kms_client_init: gsr-kms-server was not found in PATH. Please install gpu-screen-recorder properly\n");
+            return -1;
+        }
+    }
+
+    fprintf(stderr, "gsr info: gsr_kms_client_init: setting up connection to %s\n", server_filepath);
 
     const bool inside_flatpak = getenv("FLATPAK_ID") != NULL;
     const char *home = getenv("HOME");
@@ -251,7 +280,7 @@ int gsr_kms_client_init(gsr_kms_client *self, const char *card_path) {
     }
 
     local_addr.sun_family = AF_UNIX;
-    string_copy(local_addr.sun_path, self->initial_socket_path, sizeof(local_addr.sun_path));
+    snprintf(local_addr.sun_path, sizeof(local_addr.sun_path), "%s", (const char*)self->initial_socket_path);
 
     const mode_t prev_mask = umask(0000);
     const int bind_res = bind(self->initial_socket_fd, (struct sockaddr*)&local_addr, sizeof(local_addr.sun_family) + strlen(local_addr.sun_path));