diff options
Diffstat (limited to 'src/grp-machine/grp-import/systemd-pull/pull-common.c')
| -rw-r--r-- | src/grp-machine/grp-import/systemd-pull/pull-common.c | 548 |
1 files changed, 548 insertions, 0 deletions
diff --git a/src/grp-machine/grp-import/systemd-pull/pull-common.c b/src/grp-machine/grp-import/systemd-pull/pull-common.c new file mode 100644 index 0000000000..9830d8a10f --- /dev/null +++ b/src/grp-machine/grp-import/systemd-pull/pull-common.c @@ -0,0 +1,548 @@ +/*** + This file is part of systemd. + + Copyright 2015 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <sys/prctl.h> + +#include "systemd-basic/alloc-util.h" +#include "systemd-basic/btrfs-util.h" +#include "systemd-basic/capability-util.h" +#include "systemd-basic/copy.h" +#include "systemd-basic/dirent-util.h" +#include "systemd-basic/escape.h" +#include "systemd-basic/fd-util.h" +#include "systemd-basic/io-util.h" +#include "systemd-basic/path-util.h" +#include "systemd-basic/process-util.h" +#include "systemd-basic/rm-rf.h" +#include "systemd-basic/signal-util.h" +#include "systemd-basic/siphash24.h" +#include "systemd-basic/string-util.h" +#include "systemd-basic/strv.h" +#include "systemd-basic/util.h" +#include "systemd-basic/web-util.h" + +#include "pull-common.h" +#include "pull-job.h" + +#define FILENAME_ESCAPE "/.#\"\'" +#define HASH_URL_THRESHOLD_LENGTH (_POSIX_PATH_MAX - 16) + +int pull_find_old_etags( + const char *url, + const char *image_root, + int dt, + const char *prefix, + const char *suffix, + char ***etags) { + + _cleanup_free_ char *escaped_url = NULL; + _cleanup_closedir_ DIR *d = NULL; + _cleanup_strv_free_ char **l = NULL; + struct dirent *de; + int r; + + assert(url); + assert(etags); + + if (!image_root) + image_root = "/var/lib/machines"; + + escaped_url = xescape(url, FILENAME_ESCAPE); + if (!escaped_url) + return -ENOMEM; + + d = opendir(image_root); + if (!d) { + if (errno == ENOENT) { + *etags = NULL; + return 0; + } + + return -errno; + } + + FOREACH_DIRENT_ALL(de, d, return -errno) { + const char *a, *b; + char *u; + + if (de->d_type != DT_UNKNOWN && + de->d_type != dt) + continue; + + if (prefix) { + a = startswith(de->d_name, prefix); + if (!a) + continue; + } else + a = de->d_name; + + a = startswith(a, escaped_url); + if (!a) + continue; + + a = startswith(a, "."); + if (!a) + continue; + + if (suffix) { + b = endswith(de->d_name, suffix); + if (!b) + continue; + } else + b = strchr(de->d_name, 0); + + if (a >= b) + continue; + + r = cunescape_length(a, b - a, 0, &u); + if (r < 0) + return r; + + if (!http_etag_is_valid(u)) { + free(u); + continue; + } + + r = strv_consume(&l, u); + if (r < 0) + return r; + } + + *etags = l; + l = NULL; + + return 0; +} + +int pull_make_local_copy(const char *final, const char *image_root, const char *local, bool force_local) { + const char *p; + int r; + + assert(final); + assert(local); + + if (!image_root) + image_root = "/var/lib/machines"; + + p = strjoina(image_root, "/", local); + + if (force_local) + (void) rm_rf(p, REMOVE_ROOT|REMOVE_PHYSICAL|REMOVE_SUBVOLUME); + + r = btrfs_subvol_snapshot(final, p, BTRFS_SNAPSHOT_QUOTA); + if (r == -ENOTTY) { + r = copy_tree(final, p, false); + if (r < 0) + return log_error_errno(r, "Failed to copy image: %m"); + } else if (r < 0) + return log_error_errno(r, "Failed to create local image: %m"); + + log_info("Created new local image '%s'.", local); + + return 0; +} + +static int hash_url(const char *url, char **ret) { + uint64_t h; + static const sd_id128_t k = SD_ID128_ARRAY(df,89,16,87,01,cc,42,30,98,ab,4a,19,a6,a5,63,4f); + + assert(url); + + h = siphash24(url, strlen(url), k.bytes); + if (asprintf(ret, "%"PRIx64, h) < 0) + return -ENOMEM; + + return 0; +} + +int pull_make_path(const char *url, const char *etag, const char *image_root, const char *prefix, const char *suffix, char **ret) { + _cleanup_free_ char *escaped_url = NULL, *escaped_etag = NULL; + char *path; + + assert(url); + assert(ret); + + if (!image_root) + image_root = "/var/lib/machines"; + + escaped_url = xescape(url, FILENAME_ESCAPE); + if (!escaped_url) + return -ENOMEM; + + if (etag) { + escaped_etag = xescape(etag, FILENAME_ESCAPE); + if (!escaped_etag) + return -ENOMEM; + } + + path = strjoin(image_root, "/", strempty(prefix), escaped_url, escaped_etag ? "." : "", + strempty(escaped_etag), strempty(suffix), NULL); + if (!path) + return -ENOMEM; + + /* URLs might make the path longer than the maximum allowed length for a file name. + * When that happens, a URL hash is used instead. Paths returned by this function + * can be later used with tempfn_random() which adds 16 bytes to the resulting name. */ + if (strlen(path) >= HASH_URL_THRESHOLD_LENGTH) { + _cleanup_free_ char *hash = NULL; + int r; + + free(path); + + r = hash_url(url, &hash); + if (r < 0) + return r; + + path = strjoin(image_root, "/", strempty(prefix), hash, escaped_etag ? "." : "", + strempty(escaped_etag), strempty(suffix), NULL); + if (!path) + return -ENOMEM; + } + + *ret = path; + return 0; +} + +int pull_make_settings_job( + PullJob **ret, + const char *url, + CurlGlue *glue, + PullJobFinished on_finished, + void *userdata) { + + _cleanup_free_ char *last_component = NULL, *ll = NULL, *settings_url = NULL; + _cleanup_(pull_job_unrefp) PullJob *job = NULL; + const char *q; + int r; + + assert(ret); + assert(url); + assert(glue); + + r = import_url_last_component(url, &last_component); + if (r < 0) + return r; + + r = tar_strip_suffixes(last_component, &ll); + if (r < 0) + return r; + + q = strjoina(ll, ".nspawn"); + + r = import_url_change_last_component(url, q, &settings_url); + if (r < 0) + return r; + + r = pull_job_new(&job, settings_url, glue, userdata); + if (r < 0) + return r; + + job->on_finished = on_finished; + job->compressed_max = job->uncompressed_max = 1ULL * 1024ULL * 1024ULL; + + *ret = job; + job = NULL; + + return 0; +} + +int pull_make_verification_jobs( + PullJob **ret_checksum_job, + PullJob **ret_signature_job, + ImportVerify verify, + const char *url, + CurlGlue *glue, + PullJobFinished on_finished, + void *userdata) { + + _cleanup_(pull_job_unrefp) PullJob *checksum_job = NULL, *signature_job = NULL; + int r; + + assert(ret_checksum_job); + assert(ret_signature_job); + assert(verify >= 0); + assert(verify < _IMPORT_VERIFY_MAX); + assert(url); + assert(glue); + + if (verify != IMPORT_VERIFY_NO) { + _cleanup_free_ char *checksum_url = NULL; + + /* Queue job for the SHA256SUMS file for the image */ + r = import_url_change_last_component(url, "SHA256SUMS", &checksum_url); + if (r < 0) + return r; + + r = pull_job_new(&checksum_job, checksum_url, glue, userdata); + if (r < 0) + return r; + + checksum_job->on_finished = on_finished; + checksum_job->uncompressed_max = checksum_job->compressed_max = 1ULL * 1024ULL * 1024ULL; + } + + if (verify == IMPORT_VERIFY_SIGNATURE) { + _cleanup_free_ char *signature_url = NULL; + + /* Queue job for the SHA256SUMS.gpg file for the image. */ + r = import_url_change_last_component(url, "SHA256SUMS.gpg", &signature_url); + if (r < 0) + return r; + + r = pull_job_new(&signature_job, signature_url, glue, userdata); + if (r < 0) + return r; + + signature_job->on_finished = on_finished; + signature_job->uncompressed_max = signature_job->compressed_max = 1ULL * 1024ULL * 1024ULL; + } + + *ret_checksum_job = checksum_job; + *ret_signature_job = signature_job; + + checksum_job = signature_job = NULL; + + return 0; +} + +int pull_verify(PullJob *main_job, + PullJob *settings_job, + PullJob *checksum_job, + PullJob *signature_job) { + + _cleanup_close_pair_ int gpg_pipe[2] = { -1, -1 }; + _cleanup_free_ char *fn = NULL; + _cleanup_close_ int sig_file = -1; + const char *p, *line; + char sig_file_path[] = "/tmp/sigXXXXXX", gpg_home[] = "/tmp/gpghomeXXXXXX"; + _cleanup_(sigkill_waitp) pid_t pid = 0; + bool gpg_home_created = false; + int r; + + assert(main_job); + assert(main_job->state == PULL_JOB_DONE); + + if (!checksum_job) + return 0; + + assert(main_job->calc_checksum); + assert(main_job->checksum); + assert(checksum_job->state == PULL_JOB_DONE); + + if (!checksum_job->payload || checksum_job->payload_size <= 0) { + log_error("Checksum is empty, cannot verify."); + return -EBADMSG; + } + + r = import_url_last_component(main_job->url, &fn); + if (r < 0) + return log_oom(); + + if (!filename_is_valid(fn)) { + log_error("Cannot verify checksum, could not determine valid server-side file name."); + return -EBADMSG; + } + + line = strjoina(main_job->checksum, " *", fn, "\n"); + + p = memmem(checksum_job->payload, + checksum_job->payload_size, + line, + strlen(line)); + + if (!p || (p != (char*) checksum_job->payload && p[-1] != '\n')) { + log_error("DOWNLOAD INVALID: Checksum did not check out, payload has been tampered with."); + return -EBADMSG; + } + + log_info("SHA256 checksum of %s is valid.", main_job->url); + + assert(!settings_job || IN_SET(settings_job->state, PULL_JOB_DONE, PULL_JOB_FAILED)); + + if (settings_job && + settings_job->state == PULL_JOB_DONE && + settings_job->error == 0 && + !settings_job->etag_exists) { + + _cleanup_free_ char *settings_fn = NULL; + + assert(settings_job->calc_checksum); + assert(settings_job->checksum); + + r = import_url_last_component(settings_job->url, &settings_fn); + if (r < 0) + return log_oom(); + + if (!filename_is_valid(settings_fn)) { + log_error("Cannot verify checksum, could not determine server-side settings file name."); + return -EBADMSG; + } + + line = strjoina(settings_job->checksum, " *", settings_fn, "\n"); + + p = memmem(checksum_job->payload, + checksum_job->payload_size, + line, + strlen(line)); + + if (!p || (p != (char*) checksum_job->payload && p[-1] != '\n')) { + log_error("DOWNLOAD INVALID: Checksum of settings file did not checkout, settings file has been tampered with."); + return -EBADMSG; + } + + log_info("SHA256 checksum of %s is valid.", settings_job->url); + } + + if (!signature_job) + return 0; + + assert(signature_job->state == PULL_JOB_DONE); + + if (!signature_job->payload || signature_job->payload_size <= 0) { + log_error("Signature is empty, cannot verify."); + return -EBADMSG; + } + + r = pipe2(gpg_pipe, O_CLOEXEC); + if (r < 0) + return log_error_errno(errno, "Failed to create pipe for gpg: %m"); + + sig_file = mkostemp(sig_file_path, O_RDWR); + if (sig_file < 0) + return log_error_errno(errno, "Failed to create temporary file: %m"); + + r = loop_write(sig_file, signature_job->payload, signature_job->payload_size, false); + if (r < 0) { + log_error_errno(r, "Failed to write to temporary file: %m"); + goto finish; + } + + if (!mkdtemp(gpg_home)) { + r = log_error_errno(errno, "Failed to create tempory home for gpg: %m"); + goto finish; + } + + gpg_home_created = true; + + pid = fork(); + if (pid < 0) + return log_error_errno(errno, "Failed to fork off gpg: %m"); + if (pid == 0) { + const char *cmd[] = { + "gpg", + "--no-options", + "--no-default-keyring", + "--no-auto-key-locate", + "--no-auto-check-trustdb", + "--batch", + "--trust-model=always", + NULL, /* --homedir= */ + NULL, /* --keyring= */ + NULL, /* --verify */ + NULL, /* signature file */ + NULL, /* dash */ + NULL /* trailing NULL */ + }; + unsigned k = ELEMENTSOF(cmd) - 6; + int null_fd; + + /* Child */ + + (void) reset_all_signal_handlers(); + (void) reset_signal_mask(); + assert_se(prctl(PR_SET_PDEATHSIG, SIGTERM) == 0); + + gpg_pipe[1] = safe_close(gpg_pipe[1]); + + if (dup2(gpg_pipe[0], STDIN_FILENO) != STDIN_FILENO) { + log_error_errno(errno, "Failed to dup2() fd: %m"); + _exit(EXIT_FAILURE); + } + + if (gpg_pipe[0] != STDIN_FILENO) + gpg_pipe[0] = safe_close(gpg_pipe[0]); + + null_fd = open("/dev/null", O_WRONLY|O_NOCTTY); + if (null_fd < 0) { + log_error_errno(errno, "Failed to open /dev/null: %m"); + _exit(EXIT_FAILURE); + } + + if (dup2(null_fd, STDOUT_FILENO) != STDOUT_FILENO) { + log_error_errno(errno, "Failed to dup2() fd: %m"); + _exit(EXIT_FAILURE); + } + + if (null_fd != STDOUT_FILENO) + null_fd = safe_close(null_fd); + + cmd[k++] = strjoina("--homedir=", gpg_home); + + /* We add the user keyring only to the command line + * arguments, if it's around since gpg fails + * otherwise. */ + if (access(USER_KEYRING_PATH, F_OK) >= 0) + cmd[k++] = "--keyring=" USER_KEYRING_PATH; + else + cmd[k++] = "--keyring=" VENDOR_KEYRING_PATH; + + cmd[k++] = "--verify"; + cmd[k++] = sig_file_path; + cmd[k++] = "-"; + cmd[k++] = NULL; + + stdio_unset_cloexec(); + + execvp("gpg2", (char * const *) cmd); + execvp("gpg", (char * const *) cmd); + log_error_errno(errno, "Failed to execute gpg: %m"); + _exit(EXIT_FAILURE); + } + + gpg_pipe[0] = safe_close(gpg_pipe[0]); + + r = loop_write(gpg_pipe[1], checksum_job->payload, checksum_job->payload_size, false); + if (r < 0) { + log_error_errno(r, "Failed to write to pipe: %m"); + goto finish; + } + + gpg_pipe[1] = safe_close(gpg_pipe[1]); + + r = wait_for_terminate_and_warn("gpg", pid, true); + pid = 0; + if (r < 0) + goto finish; + if (r > 0) { + log_error("DOWNLOAD INVALID: Signature verification failed."); + r = -EBADMSG; + } else { + log_info("Signature verification succeeded."); + r = 0; + } + +finish: + if (sig_file >= 0) + (void) unlink(sig_file_path); + + if (gpg_home_created) + (void) rm_rf(gpg_home, REMOVE_ROOT|REMOVE_PHYSICAL); + + return r; +} |