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Diffstat (limited to 'src/import/import-common.c')
| -rw-r--r-- | src/import/import-common.c | 448 |
1 files changed, 448 insertions, 0 deletions
diff --git a/src/import/import-common.c b/src/import/import-common.c new file mode 100644 index 0000000000..395f998f16 --- /dev/null +++ b/src/import/import-common.c @@ -0,0 +1,448 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +/*** + 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 "util.h" +#include "strv.h" +#include "copy.h" +#include "btrfs-util.h" +#include "import-job.h" +#include "import-common.h" + +#define FILENAME_ESCAPE "/.#\"\'" + +int import_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; + + u = cunescape_length(a, b - a); + if (!u) + return -ENOMEM; + + 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 import_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 = strappenda(image_root, "/", local); + + if (force_local) { + (void) btrfs_subvol_remove(p); + (void) rm_rf_dangerous(p, false, true, false); + } + + r = btrfs_subvol_snapshot(final, p, false, false); + 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; +} + +int import_make_read_only_fd(int fd) { + int r; + + assert(fd >= 0); + + /* First, let's make this a read-only subvolume if it refers + * to a subvolume */ + r = btrfs_subvol_set_read_only_fd(fd, true); + if (r == -ENOTTY || r == -ENOTDIR || r == -EINVAL) { + struct stat st; + + /* This doesn't refer to a subvolume, or the file + * system isn't even btrfs. In that, case fall back to + * chmod()ing */ + + r = fstat(fd, &st); + if (r < 0) + return log_error_errno(errno, "Failed to stat temporary image: %m"); + + /* Drop "w" flag */ + if (fchmod(fd, st.st_mode & 07555) < 0) + return log_error_errno(errno, "Failed to chmod() final image: %m"); + + return 0; + + } else if (r < 0) + return log_error_errno(r, "Failed to make subvolume read-only: %m"); + + return 0; +} + +int import_make_read_only(const char *path) { + _cleanup_close_ int fd = 1; + + fd = open(path, O_RDONLY|O_NOCTTY|O_CLOEXEC); + if (fd < 0) + return log_error_errno(errno, "Failed to open %s: %m", path); + + return import_make_read_only_fd(fd); +} + +int import_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; + 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) { + _cleanup_free_ char *escaped_etag = NULL; + + escaped_etag = xescape(etag, FILENAME_ESCAPE); + if (!escaped_etag) + return -ENOMEM; + + path = strjoin(image_root, "/", strempty(prefix), escaped_url, ".", escaped_etag, strempty(suffix), NULL); + } else + path = strjoin(image_root, "/", strempty(prefix), escaped_url, strempty(suffix), NULL); + if (!path) + return -ENOMEM; + + *ret = path; + return 0; +} + +int import_make_verification_jobs( + ImportJob **ret_checksum_job, + ImportJob **ret_signature_job, + ImportVerify verify, + const char *url, + CurlGlue *glue, + ImportJobFinished on_finished, + void *userdata) { + + _cleanup_(import_job_unrefp) ImportJob *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 = import_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 = import_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 import_verify( + ImportJob *main_job, + ImportJob *checksum_job, + ImportJob *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"; + _cleanup_sigkill_wait_ pid_t pid = 0; + int r; + + assert(main_job); + assert(main_job->state == IMPORT_JOB_DONE); + + if (!checksum_job) + return 0; + + assert(main_job->calc_checksum); + assert(main_job->checksum); + assert(checksum_job->state == IMPORT_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 = strappenda(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("Checksum did not check out, payload has been tempered with."); + return -EBADMSG; + } + + log_info("SHA256 checksum of %s is valid.", main_job->url); + + if (!signature_job) + return 0; + + assert(signature_job->state == IMPORT_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; + } + + 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", + "--keyring=" VENDOR_KEYRING_PATH, + NULL, /* maybe user keyring */ + NULL, /* --verify */ + NULL, /* signature file */ + NULL, /* dash */ + NULL /* trailing NULL */ + }; + unsigned k = ELEMENTSOF(cmd) - 5; + int null_fd; + + /* Child */ + + reset_all_signal_handlers(); + 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); + + /* 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; + + cmd[k++] = "--verify"; + cmd[k++] = sig_file_path; + cmd[k++] = "-"; + cmd[k++] = NULL; + + fd_cloexec(STDIN_FILENO, false); + fd_cloexec(STDOUT_FILENO, false); + fd_cloexec(STDERR_FILENO, false); + + 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("Signature verification failed."); + r = -EBADMSG; + } else { + log_info("Signature verification succeeded."); + r = 0; + } + +finish: + if (sig_file >= 0) + unlink(sig_file_path); + + return r; +} |