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Diffstat (limited to 'src/modules/flatpak-utils.h')
| -rw-r--r-- | src/modules/flatpak-utils.h | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/src/modules/flatpak-utils.h b/src/modules/flatpak-utils.h new file mode 100644 index 0000000..8952ac4 --- /dev/null +++ b/src/modules/flatpak-utils.h @@ -0,0 +1,156 @@ +/* PipeWire + * + * Copyright © 2018 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. + */ + +#ifndef FLATPAK_UTILS_H +#define FLATPAK_UTILS_H + +#include <stdio.h> +#include <string.h> +#include <fcntl.h> +#include <sys/mman.h> +#include <sys/stat.h> +#ifdef HAVE_SYS_VFS_H +#include <sys/vfs.h> +#endif + +#include "config.h" + +#ifdef HAVE_GLIB2 +#include <glib.h> +#endif + +#include <spa/utils/result.h> +#include <pipewire/log.h> + +static int pw_check_flatpak_parse_metadata(const char *buf, size_t size, char **app_id, char **devices) +{ +#ifdef HAVE_GLIB2 + /* + * See flatpak-metadata(5) + * + * The .flatpak-info file is in GLib key_file .ini format. + */ + g_autoptr(GKeyFile) metadata = NULL; + char *s; + + metadata = g_key_file_new(); + if (!g_key_file_load_from_data(metadata, buf, size, G_KEY_FILE_NONE, NULL)) + return -EINVAL; + + if (app_id) { + s = g_key_file_get_value(metadata, "Application", "name", NULL); + *app_id = s ? strdup(s) : NULL; + g_free(s); + } + + if (devices) { + s = g_key_file_get_value(metadata, "Context", "devices", NULL); + *devices = s ? strdup(s) : NULL; + g_free(s); + } + + return 0; +#else + return -ENOTSUP; +#endif +} + +static int pw_check_flatpak(pid_t pid, char **app_id, char **devices) +{ +#if defined(__linux__) + char root_path[2048]; + int root_fd, info_fd, res; + struct stat stat_buf; + + if (app_id) + *app_id = NULL; + if (devices) + *devices = NULL; + + snprintf(root_path, sizeof(root_path), "/proc/%d/root", (int)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"); + } else if (app_id || devices) { + /* Parse the application ID if needed */ + const size_t size = stat_buf.st_size; + + if (size > 0) { + void *buf = mmap(NULL, size, PROT_READ, MAP_PRIVATE, info_fd, 0); + if (buf != MAP_FAILED) { + res = pw_check_flatpak_parse_metadata(buf, size, app_id, devices); + munmap(buf, size); + } else { + res = -errno; + } + } else { + res = -EINVAL; + } + + if (res == -EINVAL) + pw_log_error("PID %d .flatpak-info file is malformed", + (int)pid); + else if (res < 0) + pw_log_error("PID %d .flatpak-info parsing failed: %s", + (int)pid, spa_strerror(res)); + } + close(info_fd); + return 1; +#else + return 0; +#endif +} + +#endif /* FLATPAK_UTILS_H */ |