diff options
Diffstat (limited to 'src/grp-coredump/systemd-coredump/coredump.c')
| -rw-r--r-- | src/grp-coredump/systemd-coredump/coredump.c | 1303 |
1 files changed, 1303 insertions, 0 deletions
diff --git a/src/grp-coredump/systemd-coredump/coredump.c b/src/grp-coredump/systemd-coredump/coredump.c new file mode 100644 index 0000000000..9c60d04e60 --- /dev/null +++ b/src/grp-coredump/systemd-coredump/coredump.c @@ -0,0 +1,1303 @@ +/*** + This file is part of systemd. + + Copyright 2012 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 <errno.h> +#include <stdio.h> +#include <sys/prctl.h> +#include <sys/xattr.h> +#include <unistd.h> + +#ifdef HAVE_ELFUTILS +#include <dwarf.h> +#include <elfutils/libdwfl.h> +#endif + +#include <systemd/sd-daemon.h> +#include <systemd/sd-journal.h> +#include <systemd/sd-login.h> +#include <systemd/sd-messages.h> + +#include "journal-core/journald-native.h" +#include "sd-journal/compress.h" +#include "systemd-basic/alloc-util.h" +#include "systemd-basic/capability-util.h" +#include "systemd-basic/cgroup-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/fileio.h" +#include "systemd-basic/fs-util.h" +#include "systemd-basic/io-util.h" +#include "systemd-basic/log.h" +#include "systemd-basic/macro.h" +#include "systemd-basic/missing.h" +#include "systemd-basic/mkdir.h" +#include "systemd-basic/parse-util.h" +#include "systemd-basic/process-util.h" +#include "systemd-basic/socket-util.h" +#include "systemd-basic/special.h" +#include "systemd-basic/string-table.h" +#include "systemd-basic/string-util.h" +#include "systemd-basic/strv.h" +#include "systemd-basic/user-util.h" +#include "systemd-basic/util.h" +#include "systemd-shared/acl-util.h" +#include "systemd-shared/conf-parser.h" + +#include "coredump-vacuum.h" +#include "stacktrace.h" + +/* The maximum size up to which we process coredumps */ +#define PROCESS_SIZE_MAX ((uint64_t) (2LLU*1024LLU*1024LLU*1024LLU)) + +/* The maximum size up to which we leave the coredump around on disk */ +#define EXTERNAL_SIZE_MAX PROCESS_SIZE_MAX + +/* The maximum size up to which we store the coredump in the journal */ +#define JOURNAL_SIZE_MAX ((size_t) (767LU*1024LU*1024LU)) + +/* Make sure to not make this larger than the maximum journal entry + * size. See DATA_SIZE_MAX in journald-native.c. */ +assert_cc(JOURNAL_SIZE_MAX <= DATA_SIZE_MAX); + +enum { + /* We use this as array indexes for a couple of special fields we use for naming coredumping files, and + * attaching xattrs */ + CONTEXT_PID, + CONTEXT_UID, + CONTEXT_GID, + CONTEXT_SIGNAL, + CONTEXT_TIMESTAMP, + CONTEXT_RLIMIT, + CONTEXT_COMM, + CONTEXT_EXE, + _CONTEXT_MAX +}; + +typedef enum CoredumpStorage { + COREDUMP_STORAGE_NONE, + COREDUMP_STORAGE_EXTERNAL, + COREDUMP_STORAGE_JOURNAL, + _COREDUMP_STORAGE_MAX, + _COREDUMP_STORAGE_INVALID = -1 +} CoredumpStorage; + +static const char* const coredump_storage_table[_COREDUMP_STORAGE_MAX] = { + [COREDUMP_STORAGE_NONE] = "none", + [COREDUMP_STORAGE_EXTERNAL] = "external", + [COREDUMP_STORAGE_JOURNAL] = "journal", +}; + +DEFINE_PRIVATE_STRING_TABLE_LOOKUP(coredump_storage, CoredumpStorage); +static DEFINE_CONFIG_PARSE_ENUM(config_parse_coredump_storage, coredump_storage, CoredumpStorage, "Failed to parse storage setting"); + +static CoredumpStorage arg_storage = COREDUMP_STORAGE_EXTERNAL; +static bool arg_compress = true; +static uint64_t arg_process_size_max = PROCESS_SIZE_MAX; +static uint64_t arg_external_size_max = EXTERNAL_SIZE_MAX; +static size_t arg_journal_size_max = JOURNAL_SIZE_MAX; +static uint64_t arg_keep_free = (uint64_t) -1; +static uint64_t arg_max_use = (uint64_t) -1; + +static int parse_config(void) { + static const ConfigTableItem items[] = { + { "Coredump", "Storage", config_parse_coredump_storage, 0, &arg_storage }, + { "Coredump", "Compress", config_parse_bool, 0, &arg_compress }, + { "Coredump", "ProcessSizeMax", config_parse_iec_uint64, 0, &arg_process_size_max }, + { "Coredump", "ExternalSizeMax", config_parse_iec_uint64, 0, &arg_external_size_max }, + { "Coredump", "JournalSizeMax", config_parse_iec_size, 0, &arg_journal_size_max }, + { "Coredump", "KeepFree", config_parse_iec_uint64, 0, &arg_keep_free }, + { "Coredump", "MaxUse", config_parse_iec_uint64, 0, &arg_max_use }, + {} + }; + + return config_parse_many_nulstr(PKGSYSCONFDIR "/coredump.conf", + CONF_PATHS_NULSTR("systemd/coredump.conf.d"), + "Coredump\0", + config_item_table_lookup, items, + false, NULL); +} + +static inline uint64_t storage_size_max(void) { + return arg_storage == COREDUMP_STORAGE_EXTERNAL ? arg_external_size_max : arg_journal_size_max; +} + +static int fix_acl(int fd, uid_t uid) { + +#ifdef HAVE_ACL + _cleanup_(acl_freep) acl_t acl = NULL; + acl_entry_t entry; + acl_permset_t permset; + int r; + + assert(fd >= 0); + + if (uid <= SYSTEM_UID_MAX) + return 0; + + /* Make sure normal users can read (but not write or delete) + * their own coredumps */ + + acl = acl_get_fd(fd); + if (!acl) + return log_error_errno(errno, "Failed to get ACL: %m"); + + if (acl_create_entry(&acl, &entry) < 0 || + acl_set_tag_type(entry, ACL_USER) < 0 || + acl_set_qualifier(entry, &uid) < 0) + return log_error_errno(errno, "Failed to patch ACL: %m"); + + if (acl_get_permset(entry, &permset) < 0 || + acl_add_perm(permset, ACL_READ) < 0) + return log_warning_errno(errno, "Failed to patch ACL: %m"); + + r = calc_acl_mask_if_needed(&acl); + if (r < 0) + return log_warning_errno(r, "Failed to patch ACL: %m"); + + if (acl_set_fd(fd, acl) < 0) + return log_error_errno(errno, "Failed to apply ACL: %m"); +#endif + + return 0; +} + +static int fix_xattr(int fd, const char *context[_CONTEXT_MAX]) { + + static const char * const xattrs[_CONTEXT_MAX] = { + [CONTEXT_PID] = "user.coredump.pid", + [CONTEXT_UID] = "user.coredump.uid", + [CONTEXT_GID] = "user.coredump.gid", + [CONTEXT_SIGNAL] = "user.coredump.signal", + [CONTEXT_TIMESTAMP] = "user.coredump.timestamp", + [CONTEXT_COMM] = "user.coredump.comm", + [CONTEXT_EXE] = "user.coredump.exe", + }; + + int r = 0; + unsigned i; + + assert(fd >= 0); + + /* Attach some metadata to coredumps via extended + * attributes. Just because we can. */ + + for (i = 0; i < _CONTEXT_MAX; i++) { + int k; + + if (isempty(context[i]) || !xattrs[i]) + continue; + + k = fsetxattr(fd, xattrs[i], context[i], strlen(context[i]), XATTR_CREATE); + if (k < 0 && r == 0) + r = -errno; + } + + return r; +} + +#define filename_escape(s) xescape((s), "./ ") + +static inline const char *coredump_tmpfile_name(const char *s) { + return s ? s : "(unnamed temporary file)"; +} + +static int fix_permissions( + int fd, + const char *filename, + const char *target, + const char *context[_CONTEXT_MAX], + uid_t uid) { + + int r; + + assert(fd >= 0); + assert(target); + assert(context); + + /* Ignore errors on these */ + (void) fchmod(fd, 0640); + (void) fix_acl(fd, uid); + (void) fix_xattr(fd, context); + + if (fsync(fd) < 0) + return log_error_errno(errno, "Failed to sync coredump %s: %m", coredump_tmpfile_name(filename)); + + r = link_tmpfile(fd, filename, target); + if (r < 0) + return log_error_errno(r, "Failed to move coredump %s into place: %m", target); + + return 0; +} + +static int maybe_remove_external_coredump(const char *filename, uint64_t size) { + + /* Returns 1 if might remove, 0 if will not remove, < 0 on error. */ + + if (arg_storage == COREDUMP_STORAGE_EXTERNAL && + size <= arg_external_size_max) + return 0; + + if (!filename) + return 1; + + if (unlink(filename) < 0 && errno != ENOENT) + return log_error_errno(errno, "Failed to unlink %s: %m", filename); + + return 1; +} + +static int make_filename(const char *context[_CONTEXT_MAX], char **ret) { + _cleanup_free_ char *c = NULL, *u = NULL, *p = NULL, *t = NULL; + sd_id128_t boot = {}; + int r; + + assert(context); + + c = filename_escape(context[CONTEXT_COMM]); + if (!c) + return -ENOMEM; + + u = filename_escape(context[CONTEXT_UID]); + if (!u) + return -ENOMEM; + + r = sd_id128_get_boot(&boot); + if (r < 0) + return r; + + p = filename_escape(context[CONTEXT_PID]); + if (!p) + return -ENOMEM; + + t = filename_escape(context[CONTEXT_TIMESTAMP]); + if (!t) + return -ENOMEM; + + if (asprintf(ret, + "/var/lib/systemd/coredump/core.%s.%s." SD_ID128_FORMAT_STR ".%s.%s000000", + c, + u, + SD_ID128_FORMAT_VAL(boot), + p, + t) < 0) + return -ENOMEM; + + return 0; +} + +static int save_external_coredump( + const char *context[_CONTEXT_MAX], + int input_fd, + char **ret_filename, + int *ret_node_fd, + int *ret_data_fd, + uint64_t *ret_size) { + + _cleanup_free_ char *fn = NULL, *tmp = NULL; + _cleanup_close_ int fd = -1; + uint64_t rlimit, max_size; + struct stat st; + uid_t uid; + int r; + + assert(context); + assert(ret_filename); + assert(ret_node_fd); + assert(ret_data_fd); + assert(ret_size); + + r = parse_uid(context[CONTEXT_UID], &uid); + if (r < 0) + return log_error_errno(r, "Failed to parse UID: %m"); + + r = safe_atou64(context[CONTEXT_RLIMIT], &rlimit); + if (r < 0) + return log_error_errno(r, "Failed to parse resource limit: %s", context[CONTEXT_RLIMIT]); + if (rlimit < page_size()) { + /* Is coredumping disabled? Then don't bother saving/processing the coredump. + * Anything below PAGE_SIZE cannot give a readable coredump (the kernel uses + * ELF_EXEC_PAGESIZE which is not easily accessible, but is usually the same as PAGE_SIZE. */ + log_info("Resource limits disable core dumping for process %s (%s).", + context[CONTEXT_PID], context[CONTEXT_COMM]); + return -EBADSLT; + } + + /* Never store more than the process configured, or than we actually shall keep or process */ + max_size = MIN(rlimit, MAX(arg_process_size_max, storage_size_max())); + + r = make_filename(context, &fn); + if (r < 0) + return log_error_errno(r, "Failed to determine coredump file name: %m"); + + mkdir_p_label("/var/lib/systemd/coredump", 0755); + + fd = open_tmpfile_linkable(fn, O_RDWR|O_CLOEXEC, &tmp); + if (fd < 0) + return log_error_errno(fd, "Failed to create temporary file for coredump %s: %m", fn); + + r = copy_bytes(input_fd, fd, max_size, false); + if (r < 0) { + log_error_errno(r, "Cannot store coredump of %s (%s): %m", context[CONTEXT_PID], context[CONTEXT_COMM]); + goto fail; + } else if (r == 1) + log_struct(LOG_INFO, + LOG_MESSAGE("Core file was truncated to %zu bytes.", max_size), + "SIZE_LIMIT=%zu", max_size, + LOG_MESSAGE_ID(SD_MESSAGE_TRUNCATED_CORE), + NULL); + + if (fstat(fd, &st) < 0) { + log_error_errno(errno, "Failed to fstat core file %s: %m", coredump_tmpfile_name(tmp)); + goto fail; + } + + if (lseek(fd, 0, SEEK_SET) == (off_t) -1) { + log_error_errno(errno, "Failed to seek on %s: %m", coredump_tmpfile_name(tmp)); + goto fail; + } + +#if defined(HAVE_XZ) || defined(HAVE_LZ4) + /* If we will remove the coredump anyway, do not compress. */ + if (arg_compress && !maybe_remove_external_coredump(NULL, st.st_size)) { + + _cleanup_free_ char *fn_compressed = NULL, *tmp_compressed = NULL; + _cleanup_close_ int fd_compressed = -1; + + fn_compressed = strappend(fn, COMPRESSED_EXT); + if (!fn_compressed) { + log_oom(); + goto uncompressed; + } + + fd_compressed = open_tmpfile_linkable(fn_compressed, O_RDWR|O_CLOEXEC, &tmp_compressed); + if (fd_compressed < 0) { + log_error_errno(fd_compressed, "Failed to create temporary file for coredump %s: %m", fn_compressed); + goto uncompressed; + } + + r = compress_stream(fd, fd_compressed, -1); + if (r < 0) { + log_error_errno(r, "Failed to compress %s: %m", coredump_tmpfile_name(tmp_compressed)); + goto fail_compressed; + } + + r = fix_permissions(fd_compressed, tmp_compressed, fn_compressed, context, uid); + if (r < 0) + goto fail_compressed; + + /* OK, this worked, we can get rid of the uncompressed version now */ + if (tmp) + unlink_noerrno(tmp); + + *ret_filename = fn_compressed; /* compressed */ + *ret_node_fd = fd_compressed; /* compressed */ + *ret_data_fd = fd; /* uncompressed */ + *ret_size = (uint64_t) st.st_size; /* uncompressed */ + + fn_compressed = NULL; + fd = fd_compressed = -1; + + return 0; + + fail_compressed: + if (tmp_compressed) + (void) unlink(tmp_compressed); + } + +uncompressed: +#endif + + r = fix_permissions(fd, tmp, fn, context, uid); + if (r < 0) + goto fail; + + *ret_filename = fn; + *ret_data_fd = fd; + *ret_node_fd = -1; + *ret_size = (uint64_t) st.st_size; + + fn = NULL; + fd = -1; + + return 0; + +fail: + if (tmp) + (void) unlink(tmp); + return r; +} + +static int allocate_journal_field(int fd, size_t size, char **ret, size_t *ret_size) { + _cleanup_free_ char *field = NULL; + ssize_t n; + + assert(fd >= 0); + assert(ret); + assert(ret_size); + + if (lseek(fd, 0, SEEK_SET) == (off_t) -1) + return log_warning_errno(errno, "Failed to seek: %m"); + + field = malloc(9 + size); + if (!field) { + log_warning("Failed to allocate memory for coredump, coredump will not be stored."); + return -ENOMEM; + } + + memcpy(field, "COREDUMP=", 9); + + n = read(fd, field + 9, size); + if (n < 0) + return log_error_errno((int) n, "Failed to read core data: %m"); + if ((size_t) n < size) { + log_error("Core data too short."); + return -EIO; + } + + *ret = field; + *ret_size = size + 9; + + field = NULL; + + return 0; +} + +/* Joins /proc/[pid]/fd/ and /proc/[pid]/fdinfo/ into the following lines: + * 0:/dev/pts/23 + * pos: 0 + * flags: 0100002 + * + * 1:/dev/pts/23 + * pos: 0 + * flags: 0100002 + * + * 2:/dev/pts/23 + * pos: 0 + * flags: 0100002 + * EOF + */ +static int compose_open_fds(pid_t pid, char **open_fds) { + _cleanup_closedir_ DIR *proc_fd_dir = NULL; + _cleanup_close_ int proc_fdinfo_fd = -1; + _cleanup_free_ char *buffer = NULL; + _cleanup_fclose_ FILE *stream = NULL; + const char *fddelim = "", *path; + struct dirent *dent = NULL; + size_t size = 0; + int r = 0; + + assert(pid >= 0); + assert(open_fds != NULL); + + path = procfs_file_alloca(pid, "fd"); + proc_fd_dir = opendir(path); + if (!proc_fd_dir) + return -errno; + + proc_fdinfo_fd = openat(dirfd(proc_fd_dir), "../fdinfo", O_DIRECTORY|O_NOFOLLOW|O_CLOEXEC|O_PATH); + if (proc_fdinfo_fd < 0) + return -errno; + + stream = open_memstream(&buffer, &size); + if (!stream) + return -ENOMEM; + + FOREACH_DIRENT(dent, proc_fd_dir, return -errno) { + _cleanup_fclose_ FILE *fdinfo = NULL; + _cleanup_free_ char *fdname = NULL; + char line[LINE_MAX]; + int fd; + + r = readlinkat_malloc(dirfd(proc_fd_dir), dent->d_name, &fdname); + if (r < 0) + return r; + + fprintf(stream, "%s%s:%s\n", fddelim, dent->d_name, fdname); + fddelim = "\n"; + + /* Use the directory entry from /proc/[pid]/fd with /proc/[pid]/fdinfo */ + fd = openat(proc_fdinfo_fd, dent->d_name, O_NOFOLLOW|O_CLOEXEC|O_RDONLY); + if (fd < 0) + continue; + + fdinfo = fdopen(fd, "re"); + if (fdinfo == NULL) { + close(fd); + continue; + } + + FOREACH_LINE(line, fdinfo, break) { + fputs(line, stream); + if (!endswith(line, "\n")) + fputc('\n', stream); + } + } + + errno = 0; + stream = safe_fclose(stream); + + if (errno > 0) + return -errno; + + *open_fds = buffer; + buffer = NULL; + + return 0; +} + +static int get_process_ns(pid_t pid, const char *namespace, ino_t *ns) { + const char *p; + struct stat stbuf; + _cleanup_close_ int proc_ns_dir_fd; + + p = procfs_file_alloca(pid, "ns"); + + proc_ns_dir_fd = open(p, O_DIRECTORY | O_CLOEXEC | O_RDONLY); + if (proc_ns_dir_fd < 0) + return -errno; + + if (fstatat(proc_ns_dir_fd, namespace, &stbuf, /* flags */0) < 0) + return -errno; + + *ns = stbuf.st_ino; + return 0; +} + +static int get_mount_namespace_leader(pid_t pid, pid_t *container_pid) { + pid_t cpid = pid, ppid = 0; + ino_t proc_mntns; + int r = 0; + + r = get_process_ns(pid, "mnt", &proc_mntns); + if (r < 0) + return r; + + for (;;) { + ino_t parent_mntns; + + r = get_process_ppid(cpid, &ppid); + if (r < 0) + return r; + + r = get_process_ns(ppid, "mnt", &parent_mntns); + if (r < 0) + return r; + + if (proc_mntns != parent_mntns) + break; + + if (ppid == 1) + return -ENOENT; + + cpid = ppid; + } + + *container_pid = ppid; + return 0; +} + +/* Returns 1 if the parent was found. + * Returns 0 if there is not a process we can call the pid's + * container parent (the pid's process isn't 'containerized'). + * Returns a negative number on errors. + */ +static int get_process_container_parent_cmdline(pid_t pid, char** cmdline) { + int r = 0; + pid_t container_pid; + const char *proc_root_path; + struct stat root_stat, proc_root_stat; + + /* To compare inodes of / and /proc/[pid]/root */ + if (stat("/", &root_stat) < 0) + return -errno; + + proc_root_path = procfs_file_alloca(pid, "root"); + if (stat(proc_root_path, &proc_root_stat) < 0) + return -errno; + + /* The process uses system root. */ + if (proc_root_stat.st_ino == root_stat.st_ino) { + *cmdline = NULL; + return 0; + } + + r = get_mount_namespace_leader(pid, &container_pid); + if (r < 0) + return r; + + return get_process_cmdline(container_pid, 0, false, cmdline); +} + +static int change_uid_gid(const char *context[]) { + uid_t uid; + gid_t gid; + int r; + + r = parse_uid(context[CONTEXT_UID], &uid); + if (r < 0) + return r; + + if (uid <= SYSTEM_UID_MAX) { + const char *user = "systemd-coredump"; + + r = get_user_creds(&user, &uid, &gid, NULL, NULL); + if (r < 0) { + log_warning_errno(r, "Cannot resolve %s user. Proceeding to dump core as root: %m", user); + uid = gid = 0; + } + } else { + r = parse_gid(context[CONTEXT_GID], &gid); + if (r < 0) + return r; + } + + return drop_privileges(uid, gid, 0); +} + +static int submit_coredump( + const char *context[_CONTEXT_MAX], + struct iovec *iovec, + size_t n_iovec_allocated, + size_t n_iovec, + int input_fd) { + + _cleanup_close_ int coredump_fd = -1, coredump_node_fd = -1; + _cleanup_free_ char *core_message = NULL, *filename = NULL, *coredump_data = NULL; + uint64_t coredump_size = UINT64_MAX; + int r; + + assert(context); + assert(iovec); + assert(n_iovec_allocated >= n_iovec + 3); + assert(input_fd >= 0); + + /* Vacuum before we write anything again */ + (void) coredump_vacuum(-1, arg_keep_free, arg_max_use); + + /* Always stream the coredump to disk, if that's possible */ + r = save_external_coredump(context, input_fd, &filename, &coredump_node_fd, &coredump_fd, &coredump_size); + if (r < 0) + /* Skip whole core dumping part */ + goto log; + + /* If we don't want to keep the coredump on disk, remove it now, as later on we will lack the privileges for + * it. However, we keep the fd to it, so that we can still process it and log it. */ + r = maybe_remove_external_coredump(filename, coredump_size); + if (r < 0) + return r; + if (r == 0) { + const char *coredump_filename; + + coredump_filename = strjoina("COREDUMP_FILENAME=", filename); + IOVEC_SET_STRING(iovec[n_iovec++], coredump_filename); + } else if (arg_storage == COREDUMP_STORAGE_EXTERNAL) + log_info("The core will not be stored: size %zu is greater than %zu (the configured maximum)", + coredump_size, arg_external_size_max); + + /* Vacuum again, but exclude the coredump we just created */ + (void) coredump_vacuum(coredump_node_fd >= 0 ? coredump_node_fd : coredump_fd, arg_keep_free, arg_max_use); + + /* Now, let's drop privileges to become the user who owns the segfaulted process and allocate the coredump + * memory under the user's uid. This also ensures that the credentials journald will see are the ones of the + * coredumping user, thus making sure the user gets access to the core dump. Let's also get rid of all + * capabilities, if we run as root, we won't need them anymore. */ + r = change_uid_gid(context); + if (r < 0) + return log_error_errno(r, "Failed to drop privileges: %m"); + +#ifdef HAVE_ELFUTILS + /* Try to get a strack trace if we can */ + if (coredump_size <= arg_process_size_max) { + _cleanup_free_ char *stacktrace = NULL; + + r = coredump_make_stack_trace(coredump_fd, context[CONTEXT_EXE], &stacktrace); + if (r >= 0) + core_message = strjoin("MESSAGE=Process ", context[CONTEXT_PID], " (", context[CONTEXT_COMM], ") of user ", context[CONTEXT_UID], " dumped core.\n\n", stacktrace, NULL); + else if (r == -EINVAL) + log_warning("Failed to generate stack trace: %s", dwfl_errmsg(dwfl_errno())); + else + log_warning_errno(r, "Failed to generate stack trace: %m"); + } else + log_debug("Not generating stack trace: core size %zu is greater than %zu (the configured maximum)", + coredump_size, arg_process_size_max); + + if (!core_message) +#endif +log: + core_message = strjoin("MESSAGE=Process ", context[CONTEXT_PID], " (", context[CONTEXT_COMM], ") of user ", context[CONTEXT_UID], " dumped core.", NULL); + if (core_message) + IOVEC_SET_STRING(iovec[n_iovec++], core_message); + + /* Optionally store the entire coredump in the journal */ + if (arg_storage == COREDUMP_STORAGE_JOURNAL) { + if (coredump_size <= arg_journal_size_max) { + size_t sz = 0; + + /* Store the coredump itself in the journal */ + + r = allocate_journal_field(coredump_fd, (size_t) coredump_size, &coredump_data, &sz); + if (r >= 0) { + iovec[n_iovec].iov_base = coredump_data; + iovec[n_iovec].iov_len = sz; + n_iovec++; + } else + log_warning_errno(r, "Failed to attach the core to the journal entry: %m"); + } else + log_info("The core will not be stored: size %zu is greater than %zu (the configured maximum)", + coredump_size, arg_journal_size_max); + } + + assert(n_iovec <= n_iovec_allocated); + + r = sd_journal_sendv(iovec, n_iovec); + if (r < 0) + return log_error_errno(r, "Failed to log coredump: %m"); + + return 0; +} + +static void map_context_fields(const struct iovec *iovec, const char *context[]) { + + static const char * const context_field_names[_CONTEXT_MAX] = { + [CONTEXT_PID] = "COREDUMP_PID=", + [CONTEXT_UID] = "COREDUMP_UID=", + [CONTEXT_GID] = "COREDUMP_GID=", + [CONTEXT_SIGNAL] = "COREDUMP_SIGNAL=", + [CONTEXT_TIMESTAMP] = "COREDUMP_TIMESTAMP=", + [CONTEXT_COMM] = "COREDUMP_COMM=", + [CONTEXT_EXE] = "COREDUMP_EXE=", + [CONTEXT_RLIMIT] = "COREDUMP_RLIMIT=", + }; + + unsigned i; + + assert(iovec); + assert(context); + + for (i = 0; i < _CONTEXT_MAX; i++) { + size_t l; + + l = strlen(context_field_names[i]); + if (iovec->iov_len < l) + continue; + + if (memcmp(iovec->iov_base, context_field_names[i], l) != 0) + continue; + + /* Note that these strings are NUL terminated, because we made sure that a trailing NUL byte is in the + * buffer, though not included in the iov_len count. (see below) */ + context[i] = (char*) iovec->iov_base + l; + break; + } +} + +static int process_socket(int fd) { + _cleanup_close_ int coredump_fd = -1; + struct iovec *iovec = NULL; + size_t n_iovec = 0, n_iovec_allocated = 0, i; + const char *context[_CONTEXT_MAX] = {}; + int r; + + assert(fd >= 0); + + log_set_target(LOG_TARGET_AUTO); + log_parse_environment(); + log_open(); + + for (;;) { + union { + struct cmsghdr cmsghdr; + uint8_t buf[CMSG_SPACE(sizeof(int))]; + } control = {}; + struct msghdr mh = { + .msg_control = &control, + .msg_controllen = sizeof(control), + .msg_iovlen = 1, + }; + ssize_t n; + ssize_t l; + + if (!GREEDY_REALLOC(iovec, n_iovec_allocated, n_iovec + 3)) { + r = log_oom(); + goto finish; + } + + l = next_datagram_size_fd(fd); + if (l < 0) { + r = log_error_errno(l, "Failed to determine datagram size to read: %m"); + goto finish; + } + + assert(l >= 0); + + iovec[n_iovec].iov_len = l; + iovec[n_iovec].iov_base = malloc(l + 1); + if (!iovec[n_iovec].iov_base) { + r = log_oom(); + goto finish; + } + + mh.msg_iov = iovec + n_iovec; + + n = recvmsg(fd, &mh, MSG_NOSIGNAL|MSG_CMSG_CLOEXEC); + if (n < 0) { + free(iovec[n_iovec].iov_base); + r = log_error_errno(errno, "Failed to receive datagram: %m"); + goto finish; + } + + if (n == 0) { + struct cmsghdr *cmsg, *found = NULL; + /* The final zero-length datagram carries the file descriptor and tells us that we're done. */ + + free(iovec[n_iovec].iov_base); + + CMSG_FOREACH(cmsg, &mh) { + if (cmsg->cmsg_level == SOL_SOCKET && + cmsg->cmsg_type == SCM_RIGHTS && + cmsg->cmsg_len == CMSG_LEN(sizeof(int))) { + assert(!found); + found = cmsg; + } + } + + if (!found) { + log_error("Coredump file descriptor missing."); + r = -EBADMSG; + goto finish; + } + + assert(coredump_fd < 0); + coredump_fd = *(int*) CMSG_DATA(found); + break; + } + + /* Add trailing NUL byte, in case these are strings */ + ((char*) iovec[n_iovec].iov_base)[n] = 0; + iovec[n_iovec].iov_len = (size_t) n; + + cmsg_close_all(&mh); + map_context_fields(iovec + n_iovec, context); + n_iovec++; + } + + if (!GREEDY_REALLOC(iovec, n_iovec_allocated, n_iovec + 3)) { + r = log_oom(); + goto finish; + } + + /* Make sure we got all data we really need */ + assert(context[CONTEXT_PID]); + assert(context[CONTEXT_UID]); + assert(context[CONTEXT_GID]); + assert(context[CONTEXT_SIGNAL]); + assert(context[CONTEXT_TIMESTAMP]); + assert(context[CONTEXT_RLIMIT]); + assert(context[CONTEXT_COMM]); + assert(coredump_fd >= 0); + + r = submit_coredump(context, iovec, n_iovec_allocated, n_iovec, coredump_fd); + +finish: + for (i = 0; i < n_iovec; i++) + free(iovec[i].iov_base); + free(iovec); + + return r; +} + +static int send_iovec(const struct iovec iovec[], size_t n_iovec, int input_fd) { + + static const union sockaddr_union sa = { + .un.sun_family = AF_UNIX, + .un.sun_path = "/run/systemd/coredump", + }; + _cleanup_close_ int fd = -1; + size_t i; + int r; + + assert(iovec || n_iovec <= 0); + assert(input_fd >= 0); + + fd = socket(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0); + if (fd < 0) + return log_error_errno(errno, "Failed to create coredump socket: %m"); + + if (connect(fd, &sa.sa, SOCKADDR_UN_LEN(sa.un)) < 0) + return log_error_errno(errno, "Failed to connect to coredump service: %m"); + + for (i = 0; i < n_iovec; i++) { + struct msghdr mh = { + .msg_iov = (struct iovec*) iovec + i, + .msg_iovlen = 1, + }; + struct iovec copy[2]; + + for (;;) { + if (sendmsg(fd, &mh, MSG_NOSIGNAL) >= 0) + break; + + if (errno == EMSGSIZE && mh.msg_iov[0].iov_len > 0) { + /* This field didn't fit? That's a pity. Given that this is just metadata, + * let's truncate the field at half, and try again. We append three dots, in + * order to show that this is truncated. */ + + if (mh.msg_iov != copy) { + /* We don't want to modify the caller's iovec, hence let's create our + * own array, consisting of two new iovecs, where the first is a + * (truncated) copy of what we want to send, and the second one + * contains the trailing dots. */ + copy[0] = iovec[i]; + copy[1] = (struct iovec) { + .iov_base = (char[]) { '.', '.', '.' }, + .iov_len = 3, + }; + + mh.msg_iov = copy; + mh.msg_iovlen = 2; + } + + copy[0].iov_len /= 2; /* halve it, and try again */ + continue; + } + + return log_error_errno(errno, "Failed to send coredump datagram: %m"); + } + } + + r = send_one_fd(fd, input_fd, 0); + if (r < 0) + return log_error_errno(r, "Failed to send coredump fd: %m"); + + return 0; +} + +static int process_special_crash(const char *context[], int input_fd) { + _cleanup_close_ int coredump_fd = -1, coredump_node_fd = -1; + _cleanup_free_ char *filename = NULL; + uint64_t coredump_size; + int r; + + assert(context); + assert(input_fd >= 0); + + /* If we are pid1 or journald, we cut things short, don't write to the journal, but still create a coredump. */ + + if (arg_storage != COREDUMP_STORAGE_NONE) + arg_storage = COREDUMP_STORAGE_EXTERNAL; + + r = save_external_coredump(context, input_fd, &filename, &coredump_node_fd, &coredump_fd, &coredump_size); + if (r < 0) + return r; + + r = maybe_remove_external_coredump(filename, coredump_size); + if (r < 0) + return r; + + log_notice("Detected coredump of the journal daemon or PID 1, diverted to %s.", filename); + + return 0; +} + +static int process_kernel(int argc, char* argv[]) { + + /* The small core field we allocate on the stack, to keep things simple */ + char + *core_pid = NULL, *core_uid = NULL, *core_gid = NULL, *core_signal = NULL, + *core_session = NULL, *core_exe = NULL, *core_comm = NULL, *core_cmdline = NULL, + *core_cgroup = NULL, *core_cwd = NULL, *core_root = NULL, *core_unit = NULL, + *core_user_unit = NULL, *core_slice = NULL, *core_timestamp = NULL, *core_rlimit = NULL; + + /* The larger ones we allocate on the heap */ + _cleanup_free_ char + *core_owner_uid = NULL, *core_open_fds = NULL, *core_proc_status = NULL, + *core_proc_maps = NULL, *core_proc_limits = NULL, *core_proc_cgroup = NULL, *core_environ = NULL, + *core_proc_mountinfo = NULL, *core_container_cmdline = NULL; + + _cleanup_free_ char *exe = NULL, *comm = NULL; + const char *context[_CONTEXT_MAX]; + bool proc_self_root_is_slash; + struct iovec iovec[27]; + size_t n_iovec = 0; + uid_t owner_uid; + const char *p; + pid_t pid; + char *t; + int r; + + if (argc < CONTEXT_COMM + 1) { + log_error("Not enough arguments passed from kernel (%i, expected %i).", argc - 1, CONTEXT_COMM + 1 - 1); + return -EINVAL; + } + + r = parse_pid(argv[CONTEXT_PID + 1], &pid); + if (r < 0) + return log_error_errno(r, "Failed to parse PID."); + + r = get_process_comm(pid, &comm); + if (r < 0) { + log_warning_errno(r, "Failed to get COMM, falling back to the command line: %m"); + comm = strv_join(argv + CONTEXT_COMM + 1, " "); + if (!comm) + return log_oom(); + } + + r = get_process_exe(pid, &exe); + if (r < 0) + log_warning_errno(r, "Failed to get EXE, ignoring: %m"); + + context[CONTEXT_PID] = argv[CONTEXT_PID + 1]; + context[CONTEXT_UID] = argv[CONTEXT_UID + 1]; + context[CONTEXT_GID] = argv[CONTEXT_GID + 1]; + context[CONTEXT_SIGNAL] = argv[CONTEXT_SIGNAL + 1]; + context[CONTEXT_TIMESTAMP] = argv[CONTEXT_TIMESTAMP + 1]; + context[CONTEXT_RLIMIT] = argv[CONTEXT_RLIMIT + 1]; + context[CONTEXT_COMM] = comm; + context[CONTEXT_EXE] = exe; + + if (cg_pid_get_unit(pid, &t) >= 0) { + + /* If this is PID 1 disable coredump collection, we'll unlikely be able to process it later on. */ + if (streq(t, SPECIAL_INIT_SCOPE)) { + log_notice("Due to PID 1 having crashed coredump collection will now be turned off."); + (void) write_string_file("/proc/sys/kernel/core_pattern", "|/bin/false", 0); + } + + /* Let's avoid dead-locks when processing journald and init crashes, as socket activation and logging + * are unlikely to work then. */ + if (STR_IN_SET(t, SPECIAL_JOURNALD_SERVICE, SPECIAL_INIT_SCOPE)) { + free(t); + return process_special_crash(context, STDIN_FILENO); + } + + core_unit = strjoina("COREDUMP_UNIT=", t); + free(t); + + IOVEC_SET_STRING(iovec[n_iovec++], core_unit); + } + + /* OK, now we know it's not the journal, hence we can make use of it now. */ + log_set_target(LOG_TARGET_JOURNAL_OR_KMSG); + log_open(); + + if (cg_pid_get_user_unit(pid, &t) >= 0) { + core_user_unit = strjoina("COREDUMP_USER_UNIT=", t); + free(t); + + IOVEC_SET_STRING(iovec[n_iovec++], core_user_unit); + } + + core_pid = strjoina("COREDUMP_PID=", context[CONTEXT_PID]); + IOVEC_SET_STRING(iovec[n_iovec++], core_pid); + + core_uid = strjoina("COREDUMP_UID=", context[CONTEXT_UID]); + IOVEC_SET_STRING(iovec[n_iovec++], core_uid); + + core_gid = strjoina("COREDUMP_GID=", context[CONTEXT_GID]); + IOVEC_SET_STRING(iovec[n_iovec++], core_gid); + + core_signal = strjoina("COREDUMP_SIGNAL=", context[CONTEXT_SIGNAL]); + IOVEC_SET_STRING(iovec[n_iovec++], core_signal); + + core_rlimit = strjoina("COREDUMP_RLIMIT=", context[CONTEXT_RLIMIT]); + IOVEC_SET_STRING(iovec[n_iovec++], core_rlimit); + + if (sd_pid_get_session(pid, &t) >= 0) { + core_session = strjoina("COREDUMP_SESSION=", t); + free(t); + + IOVEC_SET_STRING(iovec[n_iovec++], core_session); + } + + if (sd_pid_get_owner_uid(pid, &owner_uid) >= 0) { + r = asprintf(&core_owner_uid, "COREDUMP_OWNER_UID=" UID_FMT, owner_uid); + if (r > 0) + IOVEC_SET_STRING(iovec[n_iovec++], core_owner_uid); + } + + if (sd_pid_get_slice(pid, &t) >= 0) { + core_slice = strjoina("COREDUMP_SLICE=", t); + free(t); + + IOVEC_SET_STRING(iovec[n_iovec++], core_slice); + } + + if (comm) { + core_comm = strjoina("COREDUMP_COMM=", comm); + IOVEC_SET_STRING(iovec[n_iovec++], core_comm); + } + + if (exe) { + core_exe = strjoina("COREDUMP_EXE=", exe); + IOVEC_SET_STRING(iovec[n_iovec++], core_exe); + } + + if (get_process_cmdline(pid, 0, false, &t) >= 0) { + core_cmdline = strjoina("COREDUMP_CMDLINE=", t); + free(t); + + IOVEC_SET_STRING(iovec[n_iovec++], core_cmdline); + } + + if (cg_pid_get_path_shifted(pid, NULL, &t) >= 0) { + core_cgroup = strjoina("COREDUMP_CGROUP=", t); + free(t); + + IOVEC_SET_STRING(iovec[n_iovec++], core_cgroup); + } + + if (compose_open_fds(pid, &t) >= 0) { + core_open_fds = strappend("COREDUMP_OPEN_FDS=", t); + free(t); + + if (core_open_fds) + IOVEC_SET_STRING(iovec[n_iovec++], core_open_fds); + } + + p = procfs_file_alloca(pid, "status"); + if (read_full_file(p, &t, NULL) >= 0) { + core_proc_status = strappend("COREDUMP_PROC_STATUS=", t); + free(t); + + if (core_proc_status) + IOVEC_SET_STRING(iovec[n_iovec++], core_proc_status); + } + + p = procfs_file_alloca(pid, "maps"); + if (read_full_file(p, &t, NULL) >= 0) { + core_proc_maps = strappend("COREDUMP_PROC_MAPS=", t); + free(t); + + if (core_proc_maps) + IOVEC_SET_STRING(iovec[n_iovec++], core_proc_maps); + } + + p = procfs_file_alloca(pid, "limits"); + if (read_full_file(p, &t, NULL) >= 0) { + core_proc_limits = strappend("COREDUMP_PROC_LIMITS=", t); + free(t); + + if (core_proc_limits) + IOVEC_SET_STRING(iovec[n_iovec++], core_proc_limits); + } + + p = procfs_file_alloca(pid, "cgroup"); + if (read_full_file(p, &t, NULL) >=0) { + core_proc_cgroup = strappend("COREDUMP_PROC_CGROUP=", t); + free(t); + + if (core_proc_cgroup) + IOVEC_SET_STRING(iovec[n_iovec++], core_proc_cgroup); + } + + p = procfs_file_alloca(pid, "mountinfo"); + if (read_full_file(p, &t, NULL) >=0) { + core_proc_mountinfo = strappend("COREDUMP_PROC_MOUNTINFO=", t); + free(t); + + if (core_proc_mountinfo) + IOVEC_SET_STRING(iovec[n_iovec++], core_proc_mountinfo); + } + + if (get_process_cwd(pid, &t) >= 0) { + core_cwd = strjoina("COREDUMP_CWD=", t); + free(t); + + IOVEC_SET_STRING(iovec[n_iovec++], core_cwd); + } + + if (get_process_root(pid, &t) >= 0) { + core_root = strjoina("COREDUMP_ROOT=", t); + + IOVEC_SET_STRING(iovec[n_iovec++], core_root); + + /* If the process' root is "/", then there is a chance it has + * mounted own root and hence being containerized. */ + proc_self_root_is_slash = strcmp(t, "/") == 0; + free(t); + if (proc_self_root_is_slash && get_process_container_parent_cmdline(pid, &t) > 0) { + core_container_cmdline = strappend("COREDUMP_CONTAINER_CMDLINE=", t); + free(t); + + if (core_container_cmdline) + IOVEC_SET_STRING(iovec[n_iovec++], core_container_cmdline); + } + } + + if (get_process_environ(pid, &t) >= 0) { + core_environ = strappend("COREDUMP_ENVIRON=", t); + free(t); + + if (core_environ) + IOVEC_SET_STRING(iovec[n_iovec++], core_environ); + } + + core_timestamp = strjoina("COREDUMP_TIMESTAMP=", context[CONTEXT_TIMESTAMP], "000000"); + IOVEC_SET_STRING(iovec[n_iovec++], core_timestamp); + + IOVEC_SET_STRING(iovec[n_iovec++], "MESSAGE_ID=fc2e22bc6ee647b6b90729ab34a250b1"); + + assert_cc(2 == LOG_CRIT); + IOVEC_SET_STRING(iovec[n_iovec++], "PRIORITY=2"); + + assert(n_iovec <= ELEMENTSOF(iovec)); + + return send_iovec(iovec, n_iovec, STDIN_FILENO); +} + +int main(int argc, char *argv[]) { + int r; + + /* First, log to a safe place, since we don't know what crashed and it might be journald which we'd rather not + * log to then. */ + + log_set_target(LOG_TARGET_KMSG); + log_open(); + + /* Make sure we never enter a loop */ + (void) prctl(PR_SET_DUMPABLE, 0); + + /* Ignore all parse errors */ + (void) parse_config(); + + log_debug("Selected storage '%s'.", coredump_storage_to_string(arg_storage)); + log_debug("Selected compression %s.", yes_no(arg_compress)); + + r = sd_listen_fds(false); + if (r < 0) { + log_error_errno(r, "Failed to determine number of file descriptor: %m"); + goto finish; + } + + /* If we got an fd passed, we are running in coredumpd mode. Otherwise we are invoked from the kernel as + * coredump handler */ + if (r == 0) + r = process_kernel(argc, argv); + else if (r == 1) + r = process_socket(SD_LISTEN_FDS_START); + else { + log_error("Received unexpected number of file descriptors."); + r = -EINVAL; + } + +finish: + return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS; +} |