firecfg: option to fix .desktop files

1 files changed, 171 insertions, 0 deletions

diff --git a/src/firecfg/main.c b/src/firecfg/main.c
index 9c7c49e1d..8ca56a2ff 100644
--- a/src/firecfg/main.c
+++ b/src/firecfg/main.c
@@ -24,7 +24,11 @@
 #include <dirent.h>
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <fcntl.h>
 #include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/mman.h>
 #include "../include/common.h"
 static int arg_debug = 0;
 
@@ -41,6 +45,7 @@ static void usage(void) {
         printf("   --debug - print debug messages.\n\n");
         printf("   --help, -? - this help screen.\n\n");
         printf("   --list - list all firejail symbolic links.\n\n");
+        printf("   --fix - fix .desktop files.\n\n");
         printf("   --version - print program version and exit.\n\n");
         printf("Example:\n\n");
         printf("   $ sudo firecfg\n");
@@ -55,6 +60,10 @@ static void usage(void) {
         printf("   /usr/local/bin/firefox removed\n");
         printf("   /usr/local/bin/vlc removed\n");
         printf("   [...]\n");
+        printf("   $ firecfg --fix\n");
+        printf("   /home/user/.local/share/applications/chromium.desktop created\n");
+        printf("   /home/user/.local/share/applications/vlc.desktop created\n");
+        printf("   [...]\n");
         printf("\n");
         printf("License GPL version 2 or later\n");
         printf("Homepage: http://firejail.wordpress.com\n\n");
@@ -285,6 +294,164 @@ static void set(void) {
         free(firejail_exec);
 }
 
+static void fix_desktop_files(void) {
+        if (getuid() == 0) {
+                fprintf(stderr, "Error: you should run --fix as user\n");
+                exit(1);
+        }
+
+        char *homedir = getenv("HOME");
+        if (!homedir)
+                errExit("getenv");
+
+        char *user_apps_dir;
+        if (asprintf(&user_apps_dir, "%s/.local/share/applications", homedir) == -1)
+                errExit("asprintf");
+
+        DIR *dir = opendir("/usr/share/applications");
+        if (!dir) {
+                perror("Error: cannot open /usr/share/applications directory");
+                exit(1);
+        }
+
+        if (chdir("/usr/share/applications")) {
+                perror("Error: cannot chdir to /usr/share/applications");
+                exit(1);
+        }
+
+        struct dirent *entry;
+        while ((entry = readdir(dir)) != NULL) {
+                if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0)
+                        continue;
+
+                // skip if not regular file or link
+                if (entry->d_type != DT_REG && entry->d_type != DT_LNK)
+                        continue;
+
+                // skip if not .desktop file
+                if (strstr(entry->d_name,".desktop") != (entry->d_name+strlen(entry->d_name)-8))
+                        continue;
+
+                char *filename = entry->d_name;
+
+                // skip links
+                if (is_link(filename))
+                        continue;
+
+                struct stat sb;
+                if (stat(filename, &sb) == -1)
+                        errExit("stat");
+
+                int fd = open(filename, O_RDONLY);
+                if (fd == -1)
+                        errExit("open");
+
+                char *buf = mmap(NULL, sb.st_size + 1, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
+                if (buf == MAP_FAILED)
+                        errExit("mmap");
+
+                close(fd);
+
+                // check format
+                if (strstr(buf, "[Desktop Entry]\n") == NULL) {
+                        if (arg_debug)
+                                fprintf(stderr, "/usr/share/applications/%s - SKIPPED: wrong format?\n", filename);
+                        munmap(buf, sb.st_size + 1);
+                        continue;
+                }
+
+                // get executable name
+                char *ptr1 = strstr(buf,"\nExec=");
+                if (!ptr1 || strlen(ptr1) < 7) {
+                        if (arg_debug)
+                                fprintf(stderr, "/usr/share/applications/%s - SKIPPED: wrong format?\n", filename);
+                        munmap(buf, sb.st_size + 1);
+                        continue;
+                }
+
+                char *execname = ptr1 + 6;
+                // https://specifications.freedesktop.org/desktop-entry-spec/latest/ar01s06.html
+                // The executable program can either be specified with its full path
+                // or with the name of the executable only
+                if (execname[0] != '/') {
+                        if (arg_debug)
+                                fprintf(stderr, "/usr/share/applications/%s - already OK\n", filename);
+                        continue;
+                }
+                // executable name can be quoted, this is rare and currently unsupported, TODO
+                if (execname[0] == '"') {
+                        if (arg_debug)
+                                fprintf(stderr, "/usr/share/applications/%s - skipped: path quoting unsupported\n", filename);
+                        continue;
+                }
+
+                // put '\0' at end of filename
+                char *tail = NULL;
+                char endchar;
+                if (execname[0] == '/') {
+                        char *ptr2 = index(execname, ' ');
+                        char *ptr3 = index(execname, '\n');
+                        if (ptr2 && (!ptr3 || (ptr2 < ptr3))) {
+                                endchar = ptr2[0];
+                                ptr2[0] = '\0';
+                                tail = ptr2 + 1;
+                        } else if (ptr3 && (!ptr2 || (ptr3 < ptr2))) {
+                                endchar = ptr3[0];
+                                ptr3[0] = '\0';
+                                tail = ptr3 + 1;
+                        }
+                        ptr1[5] = '\0';
+                }
+
+                char *bname = basename(execname);
+                assert(bname);
+
+                // check if basename in PATH
+                if (!which(bname)) {
+                        fprintf(stderr, "/usr/share/applications/%s - unable to fix: executable not in PATH\n", filename);
+                        continue;
+                }
+
+                char *outname;
+                if (asprintf(&outname ,"%s/%s", user_apps_dir, filename) == -1)
+                        errExit("asprintf");
+
+                int fd1 = open(outname, O_CREAT | O_WRONLY | O_EXCL, S_IRUSR | S_IWUSR);
+                free(outname);
+
+                if (fd1 == -1) {
+                        fprintf(stderr, "%s/%s skipped: %s\n", user_apps_dir, filename, strerror(errno));
+                        munmap(buf, sb.st_size + 1);
+                        continue;
+                }
+
+                FILE *outfile = fdopen(fd1, "w");
+                if (!outfile) {
+                        fprintf(stderr, "%s/%s skipped: %s\n", user_apps_dir, filename, strerror(errno));
+                        munmap(buf, sb.st_size + 1);
+                        close(fd1);
+                        continue;
+                }
+
+                if (fprintf(outfile,\
+                "# Converted by firecfg --fix from /usr/share/applications/%s\n\n%s=%s%c%s",\
+                filename, buf, bname, endchar, tail) < 0) {
+                        fprintf(stderr, "Unable to write %s/%s: %s\n", user_apps_dir, filename, strerror(errno));
+                        munmap(buf, sb.st_size + 1);
+                        fclose(outfile);
+                        continue;
+                }
+
+                fclose(outfile);
+                munmap(buf, sb.st_size + 1);
+
+                printf("%s/%s created\n", user_apps_dir, filename);
+        }
+
+        closedir(dir);
+        free(user_apps_dir);
+}
+
 int main(int argc, char **argv) {
         int i;
         
@@ -309,6 +476,10 @@ int main(int argc, char **argv) {
                         list();
                         return 0;
                 }
+                else if (strcmp(argv[i], "--fix") == 0) {
+                        fix_desktop_files();
+                        return 0;
+                }
                 else {
                         fprintf(stderr, "Error: invalid command line option\n");
                         usage();