pulse-server: split out utils

Part of !776.

src/modules/module-protocol-pulse/utils.c

@@ -0,0 +1,204 @@
+/* PipeWire
+ *
+ * Copyright © 2020 Wim Taymans
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#define NAME "pulse-server"
+
+#include "config.h"
+
+#include <errno.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <limits.h>
+
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#ifdef HAVE_SYS_VFS_H
+#include <sys/vfs.h>
+#endif
+#ifdef HAVE_PWD_H
+#include <pwd.h>
+#endif
+
+#include <spa/utils/result.h>
+#include <pipewire/context.h>
+#include <pipewire/log.h>
+#include <pipewire/keys.h>
+
+#include "utils.h"
+
+int get_runtime_dir(char *buf, size_t buflen, const char *dir)
+{
+	const char *runtime_dir;
+	struct stat stat_buf;
+	int res, size;
+
+	runtime_dir = getenv("PULSE_RUNTIME_PATH");
+	if (runtime_dir == NULL)
+		runtime_dir = getenv("XDG_RUNTIME_DIR");
+	if (runtime_dir == NULL)
+		runtime_dir = getenv("HOME");
+	if (runtime_dir == NULL) {
+		struct passwd pwd, *result = NULL;
+		char buffer[4096];
+		if (getpwuid_r(getuid(), &pwd, buffer, sizeof(buffer), &result) == 0)
+			runtime_dir = result ? result->pw_dir : NULL;
+	}
+	size = snprintf(buf, buflen, "%s/%s", runtime_dir, dir) + 1;
+	if (size > (int) buflen) {
+		pw_log_error(NAME": path %s/%s too long", runtime_dir, dir);
+		return -ENAMETOOLONG;
+	}
+	if (stat(buf, &stat_buf) < 0) {
+		res = -errno;
+		if (res != -ENOENT) {
+			pw_log_error(NAME": stat() %s failed: %m", buf);
+			return res;
+		}
+		if (mkdir(buf, 0700) < 0) {
+			res = -errno;
+			pw_log_error(NAME": mkdir() %s failed: %m", buf);
+			return res;
+		}
+		pw_log_info(NAME": created %s", buf);
+	} else if ((stat_buf.st_mode & S_IFMT) != S_IFDIR) {
+		pw_log_error(NAME": %s is not a directory", buf);
+		return -ENOTDIR;
+	}
+	return 0;
+}
+
+int check_flatpak(struct client *client, int pid)
+{
+	char root_path[2048];
+	int root_fd, info_fd, res;
+	struct stat stat_buf;
+
+	sprintf(root_path, "/proc/%u/root", pid);
+	root_fd = openat(AT_FDCWD, root_path, O_RDONLY | O_NONBLOCK | O_DIRECTORY | O_CLOEXEC | O_NOCTTY);
+	if (root_fd == -1) {
+		res = -errno;
+		if (res == -EACCES) {
+			struct statfs buf;
+			/* Access to the root dir isn't allowed. This can happen if the root is on a fuse
+			 * filesystem, such as in a toolbox container. We will never have a fuse rootfs
+			 * in the flatpak case, so in that case its safe to ignore this and
+			 * continue to detect other types of apps. */
+			if (statfs(root_path, &buf) == 0 &&
+			    buf.f_type == 0x65735546) /* FUSE_SUPER_MAGIC */
+				return 0;
+		}
+		/* Not able to open the root dir shouldn't happen. Probably the app died and
+		 * we're failing due to /proc/$pid not existing. In that case fail instead
+		 * of treating this as privileged. */
+		pw_log_info("failed to open \"%s\": %s", root_path, spa_strerror(res));
+		return res;
+	}
+	info_fd = openat(root_fd, ".flatpak-info", O_RDONLY | O_CLOEXEC | O_NOCTTY);
+	close(root_fd);
+	if (info_fd == -1) {
+		if (errno == ENOENT) {
+			pw_log_debug("no .flatpak-info, client on the host");
+			/* No file => on the host */
+			return 0;
+		}
+		res = -errno;
+		pw_log_error("error opening .flatpak-info: %m");
+		return res;
+	}
+	if (fstat(info_fd, &stat_buf) != 0 || !S_ISREG(stat_buf.st_mode)) {
+		/* Some weird fd => failure, assume sandboxed */
+		pw_log_error("error fstat .flatpak-info: %m");
+	}
+	close(info_fd);
+	return 1;
+}
+
+int get_client_pid(struct client *client, int client_fd)
+{
+	socklen_t len;
+#if defined(__linux__)
+	struct ucred ucred;
+	len = sizeof(ucred);
+	if (getsockopt(client_fd, SOL_SOCKET, SO_PEERCRED, &ucred, &len) < 0) {
+		pw_log_warn("client %p: no peercred: %m", client);
+	} else
+		return ucred.pid;
+#elif defined(__FreeBSD__)
+	struct xucred xucred;
+	len = sizeof(xucred);
+	if (getsockopt(client_fd, 0, LOCAL_PEERCRED, &xucred, &len) < 0) {
+		pw_log_warn("client %p: no peercred: %m", client);
+	} else {
+#if __FreeBSD__ >= 13
+		return xucred.cr_pid;
+#endif
+	}
+#endif
+	return 0;
+}
+
+const char *get_server_name(struct pw_context *context)
+{
+	const char *name = NULL;
+	const struct pw_properties *props = pw_context_get_properties(context);
+
+	if (props)
+		name = pw_properties_get(props, PW_KEY_REMOTE_NAME);
+	if (name == NULL || name[0] == '\0')
+		name = getenv("PIPEWIRE_REMOTE");
+	if (name == NULL || name[0] == '\0')
+		name = PW_DEFAULT_REMOTE;
+	return name;
+}
+
+int create_pid_file(void) {
+	char pid_file[PATH_MAX];
+	FILE *f;
+	int res;
+
+	if ((res = get_runtime_dir(pid_file, sizeof(pid_file), "pulse")) < 0)
+		return res;
+
+	if (strlen(pid_file) > PATH_MAX - 5) {
+		pw_log_error(NAME": path too long: %s/pid", pid_file);
+		return -ENAMETOOLONG;
+	}
+
+	strcat(pid_file, "/pid");
+
+	if ((f = fopen(pid_file, "w")) == NULL) {
+		res = -errno;
+		pw_log_error(NAME": failed to open pid file: %m");
+		return res;
+	}
+
+	fprintf(f, "%lu\n", (unsigned long) getpid());
+	fclose(f);
+
+	return 0;
+}