import: rename download code from "import" to "pull"

That way we can call the code for local container/VM imports "import"
without confusion.

1 files changed, 545 insertions, 0 deletions

diff --git a/src/import/pull-common.c b/src/import/pull-common.c
new file mode 100644
index 0000000000..38380fc018
--- /dev/null
+++ b/src/import/pull-common.c
@@ -0,0 +1,545 @@
+/*-*- 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 "capability.h"
+#include "pull-job.h"
+#include "pull-common.h"
+
+#define FILENAME_ESCAPE "/.#\"\'"
+
+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;
+
+                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 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) 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 pull_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 pull_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 pull_make_read_only_fd(fd);
+}
+
+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;
+        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 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 *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_wait_ 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("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 == 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 */
+
+                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);
+
+                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;
+
+                fd_cloexec(STDIN_FILENO, false);
+                fd_cloexec(STDOUT_FILENO, false);
+                fd_cloexec(STDERR_FILENO, false);
+
+                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("Signature verification failed.");
+                r = -EBADMSG;
+        } else {
+                log_info("Signature verification succeeded.");
+                r = 0;
+        }
+
+finish:
+        if (sig_file >= 0)
+                unlink(sig_file_path);
+
+        if (gpg_home_created)
+                rm_rf_dangerous(gpg_home, false, true, false);
+
+        return r;
+}
+
+int pull_fork_tar(const char *path, pid_t *ret) {
+        _cleanup_close_pair_ int pipefd[2] = { -1, -1 };
+        pid_t pid;
+        int r;
+
+        assert(path);
+        assert(ret);
+
+        if (pipe2(pipefd, O_CLOEXEC) < 0)
+                return log_error_errno(errno, "Failed to create pipe for tar: %m");
+
+        pid = fork();
+        if (pid < 0)
+                return log_error_errno(errno, "Failed to fork off tar: %m");
+
+        if (pid == 0) {
+                int null_fd;
+                uint64_t retain =
+                        (1ULL << CAP_CHOWN) |
+                        (1ULL << CAP_FOWNER) |
+                        (1ULL << CAP_FSETID) |
+                        (1ULL << CAP_MKNOD) |
+                        (1ULL << CAP_SETFCAP) |
+                        (1ULL << CAP_DAC_OVERRIDE);
+
+                /* Child */
+
+                reset_all_signal_handlers();
+                reset_signal_mask();
+                assert_se(prctl(PR_SET_PDEATHSIG, SIGTERM) == 0);
+
+                pipefd[1] = safe_close(pipefd[1]);
+
+                if (dup2(pipefd[0], STDIN_FILENO) != STDIN_FILENO) {
+                        log_error_errno(errno, "Failed to dup2() fd: %m");
+                        _exit(EXIT_FAILURE);
+                }
+
+                if (pipefd[0] != STDIN_FILENO)
+                        pipefd[0] = safe_close(pipefd[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);
+
+                fd_cloexec(STDIN_FILENO, false);
+                fd_cloexec(STDOUT_FILENO, false);
+                fd_cloexec(STDERR_FILENO, false);
+
+                if (unshare(CLONE_NEWNET) < 0)
+                        log_error_errno(errno, "Failed to lock tar into network namespace, ignoring: %m");
+
+                r = capability_bounding_set_drop(~retain, true);
+                if (r < 0)
+                        log_error_errno(r, "Failed to drop capabilities, ignoring: %m");
+
+                execlp("tar", "tar", "--numeric-owner", "-C", path, "-px", NULL);
+                log_error_errno(errno, "Failed to execute tar: %m");
+                _exit(EXIT_FAILURE);
+        }
+
+        pipefd[0] = safe_close(pipefd[0]);
+        r = pipefd[1];
+        pipefd[1] = -1;
+
+        *ret = pid;
+
+        return r;
+}