[sb2] Add support for posix_spawnp(). Contributes to JB#51819

Signed-off-by: Björn Bidar <bjorn.bidar@jolla.com>

scratchbox2/execs/sb_exec.c

@@ -12,8 +12,8 @@
  * Brief description of the algorithm follows:
  * 
  * 0. When an application wants to execute another program, it makes a call
- *    to one of execl(), execle(), execlp(), execv(), execve(), execvp() or
- *    posix_spawn().
+ *    to one of execl(), execle(), execlp(), execv(), execve(), execvp(),
+ *    posix_spawn() or posix_spawnp().
  *    That call will be handled by one of the gate functions in 
  *    preload/libsb2.c. Eventually, the gate function will call "do_exec()"
  *    from this file; do_exec() calls prepare_exec() and that is the place

scratchbox2/preload/execgates.c

@@ -475,6 +475,136 @@ static int do_execvep(
 	return -1;
 }
 
+static int do_posix_spawnp(
+    int *result_errno_ptr,
+    const char *realfnname, pid_t *pid, const char *file,
+    const posix_spawn_file_actions_t *file_actions,
+    const posix_spawnattr_t *attrp,
+    char *const *argv, char *const *envp)
+{
+        int result;
+    	if (*file == '\0') {
+		/* We check the simple case first. */
+		*result_errno_ptr = ENOENT;
+		return ENOENT;
+	}
+
+	if (strchr (file, '/') != NULL) {
+                /* Try to execute this name.  If it works, execv will not return.  */
+                result = do_posix_spawn(result_errno_ptr,
+                                        realfnname, pid, file,
+                                        file_actions, attrp,
+                                        argv, envp);
+
+                if (*result_errno_ptr == ENOEXEC) {
+                        char **new_argv = create_argv_for_script_exec(
+                                file, argv);
+                        result = do_posix_spawn(result_errno_ptr,
+                                                realfnname, pid, new_argv[0],
+                                                file_actions, attrp,
+                                                new_argv, envp);
+                        free(new_argv);
+                }
+
+                return(result);
+	} else {
+		int got_eacces = 0;
+		const char *p;
+		const char *path;
+		char *name;
+		size_t len;
+		size_t pathlen;
+
+		path = getenv ("PATH");
+		if (path) path = strdup(path);
+		if (path == NULL) {
+			/* There is no `PATH' in the environment.
+			   The default search path is the current directory
+			   followed by the path `confstr' returns for `_CS_PATH'.  */
+			char *new_path;
+			len = confstr (_CS_PATH, (char *) NULL, 0);
+			new_path = (char *) alloca (1 + len);
+			new_path[0] = ':';
+			(void) confstr (_CS_PATH, new_path + 1, len);
+			path = new_path;
+		}
+
+		len = strlen (file) + 1;
+		pathlen = strlen (path);
+		name = alloca (pathlen + len + 1);
+		/* Copy the file name at the top.  */
+		name = (char *) memcpy (name + pathlen + 1, file, len);
+		/* And add the slash.  */
+		*--name = '/';
+
+		p = path;
+		do {
+			char *startp;
+
+			path = p;
+			p = sb2_strchrnul (path, ':');
+
+			if (p == path) {
+				/* Two adjacent colons, or a colon at the beginning or the end
+				   of `PATH' means to search the current directory.  */
+				startp = name + 1;
+			} else {
+				startp = (char *) memcpy (name - (p - path), path, p - path);
+			}
+                        result = do_posix_spawn(result_errno_ptr,
+                                         realfnname, pid, startp,
+                                         file_actions, attrp, argv, envp);
+
+			if (*result_errno_ptr == ENOEXEC) {
+				char **new_argv = create_argv_for_script_exec(
+					startp, argv);
+                                result =  do_posix_spawn(result_errno_ptr,
+                                                 realfnname, pid, new_argv[0],
+                                                 file_actions, attrp,
+                                                 new_argv, envp);
+				free(new_argv);
+			}
+                        if (result == 0)
+                            return result;
+
+                        switch (*result_errno_ptr) {
+                        case EACCES:
+                            /* Record the we got a `Permission denied' error.  If we end
+                               up finding no executable we can use, we want to diagnose
+                               that we did find one but were denied access.  */
+                            got_eacces = 1;
+                        case ENOENT:
+                        case ESTALE:
+                        case ENOTDIR:
+                            /* Those errors indicate the file is missing or not executable
+                               by us, in which case we want to just try the next path
+                               directory.  */
+                            break;
+
+                        default:
+                            /* Some other error means we found an executable file, but
+                               something went wrong executing it; return the error to our
+                               caller.  */
+                            SB_LOG(SB_LOGLEVEL_WARNING,
+                                   "%s: unkown errno, "
+                                   "something may be wrong: %i",
+                                   realfnname, *result_errno_ptr);
+                            return result;
+                        }
+		} while (*p++ != '\0');
+
+		/* We tried every element and none of them worked.  */
+		if (got_eacces)
+			/* At least one failure was due to permissions, so report that
+			   error.  */
+			*result_errno_ptr = EACCES;
+	}
+
+	/* Return the error from the last attempt (probably ENOENT).  */
+	return result;
+}
+
+
 int sb_execvep(
 	const char *file,
 	char *const argv [],
@@ -531,6 +661,25 @@ int posix_spawn_gate(
         file_actions, attrp, argv, envp);
 }
 
+int posix_spawnp_gate(
+    int *result_errno_ptr,
+    int (*real_posix_spawnp_ptr)(pid_t *pid, const char *file,
+        const posix_spawn_file_actions_t *file_actions,
+        const posix_spawnattr_t *attrp,
+        char *const argv[], char *const envp[]),
+	const char *realfnname,
+    pid_t *pid,
+    const char *file,
+    const posix_spawn_file_actions_t *file_actions,
+    const posix_spawnattr_t *attrp,
+    char *const argv[],
+    char *const envp[])
+{
+	(void)real_posix_spawnp_ptr;
+    return do_posix_spawnp(result_errno_ptr, realfnname, pid, file,
+        file_actions, attrp, argv, envp);
+}
+
 /* SETRLIMIT_ARG1_TYPE is defined in interface.master */
 
 int setrlimit_gate(

scratchbox2/preload/interface.master

@@ -115,6 +115,10 @@ GATE: int posix_spawn (pid_t *pid, const char *path, \
                        const posix_spawn_file_actions_t *file_actions, \
                        const posix_spawnattr_t *attrp, \
                        char *const argv[], char *const envp[])
+GATE: int posix_spawnp (pid_t *pid, const char *file, \
+                       const posix_spawn_file_actions_t *file_actions, \
+                       const posix_spawnattr_t *attrp, \
+                       char *const argv[], char *const envp[])
 
 GATE: char * getcwd (char *buf, size_t size) : \
 	returns_string create_nomap_nolog_version