Adding the possibility to notify a parent, via a file descriptor, that everything went fine. Useful in combination with PAM and forking.

Author: silverdaz

src/fs.c

@@ -674,7 +674,7 @@ crypt4gh_sqlite_read(fuse_req_t req, fuse_ino_t ino,
     data_fbuf = (struct fuse_buf *)calloc(1, sizeof(struct fuse_buf));
     if(!data_fbuf){ err = -ENOMEM; goto error; }
 
-    if(fh->header){ // Try Crypt4GH data
+    if(config.seckeypath && fh->header){ // Try Crypt4GH data
 
       data_fbuf->mem = calloc(data_size, sizeof(char));
       if(!data_fbuf->mem){ err = -ENOMEM; goto error; }

src/includes.h

@@ -139,6 +139,9 @@ struct fs_config {
   uint8_t seckey[crypto_kx_SECRETKEYBYTES]; /* unlocked secret key. TODO: better protect it */
   uint8_t pubkey[crypto_kx_PUBLICKEYBYTES];
 
+  /* PAM notify */
+  int parent_fd;
+
   /* SQLite database */
   char* db_path;
   sqlite3* db;

src/main.c

@@ -83,6 +83,8 @@ static struct fuse_opt fs_opts[] = {
 	CRYPT4GH_SQLITE_OPT("seckey=%s"             , seckeypath         , 0),
 	CRYPT4GH_SQLITE_OPT("passphrase_from_env=%s", passphrase_from_env, 0),
 
+	CRYPT4GH_SQLITE_OPT("parent_fd=%u", parent_fd, -1),
+
 	/* if multithreaded */
 	CRYPT4GH_SQLITE_OPT("-s"              , singlethread    , 1),
 	CRYPT4GH_SQLITE_OPT("clone_fd"        , clone_fd        , 1),
@@ -205,10 +207,16 @@ c4gh_init(void)
 {
   int res = 0;
 
-  D1("Initializing the file system");
+  if(config.seckeypath == NULL){
+    D1("Crypt4GH decryption disabled");
+    return 0; // it's allowed
+  }
+
+  D1("Initializing Crypt4GH");
+  D1("Secret key path: %s", config.seckeypath);
 
-  if(!config.seckeypath || *config.seckeypath != '/'){
-    E("Missing secret key path, or non-absolute path");
+  if(*config.seckeypath != '/'){
+    E("Secret key must be an absolute path");
     res ++;
     goto bailout;
   }
@@ -288,6 +296,7 @@ int main(int argc, char *argv[])
   config.singlethread = 0;
   config.foreground = 0;
   config.mounted_at = time(NULL);
+  config.parent_fd = -1;
 
   config.entry_timeout = DEFAULT_ENTRY_TIMEOUT;
   config.attr_timeout = DEFAULT_ATTR_TIMEOUT;
@@ -436,6 +445,19 @@ int main(int argc, char *argv[])
      config.fperm,
      config.dperm);
 
+  /* Notify the parent */
+  if(config.parent_fd > 0){
+    char data= '1';
+    if(write(config.parent_fd, &data, 1) != 1){
+      E("Error writing back to the parent: %s", strerror(errno));
+      res = 7;
+      /* should we close the parent_fd on error ? */
+      goto bailout_unmount;
+    }
+    close(config.parent_fd);
+    config.parent_fd = -1;
+  }
+
   if (config.singlethread){
     D2("Mode: single-threaded");
     res = fuse_session_loop(se);