#include "memory-util.h"
#include "memstream-util.h"
#include "mkdir-label.h"
+#include "namespace-util.h"
#include "parse-util.h"
+#include "path-util.h"
#include "process-util.h"
#include "signal-util.h"
#include "socket-util.h"
return save_context(context, iovw);
}
+static int send_ucred(int transport_fd, struct ucred *ucred) {
+ CMSG_BUFFER_TYPE(CMSG_SPACE(sizeof(struct ucred))) control = {};
+ struct msghdr mh = {
+ .msg_control = &control,
+ .msg_controllen = sizeof(control),
+ };
+ struct cmsghdr *cmsg;
+
+ assert(transport_fd >= 0);
+
+ cmsg = CMSG_FIRSTHDR(&mh);
+ *cmsg = (struct cmsghdr) {
+ .cmsg_level = SOL_SOCKET,
+ .cmsg_type = SCM_CREDENTIALS,
+ .cmsg_len = CMSG_LEN(sizeof(struct ucred)),
+ };
+ memcpy(CMSG_DATA(cmsg), ucred, sizeof(struct ucred));
+
+ return RET_NERRNO(sendmsg(transport_fd, &mh, MSG_NOSIGNAL));
+}
+
+static int receive_ucred(int transport_fd, struct ucred *ret_ucred) {
+ CMSG_BUFFER_TYPE(CMSG_SPACE(sizeof(struct ucred))) control = {};
+ struct msghdr mh = {
+ .msg_control = &control,
+ .msg_controllen = sizeof(control),
+ };
+ struct cmsghdr *cmsg = NULL;
+ struct ucred *ucred = NULL;
+ ssize_t n;
+
+ assert(ret_ucred);
+
+ n = recvmsg_safe(transport_fd, &mh, 0);
+ if (n < 0)
+ return n;
+
+ CMSG_FOREACH(cmsg, &mh)
+ if (cmsg->cmsg_level == SOL_SOCKET &&
+ cmsg->cmsg_type == SCM_CREDENTIALS &&
+ cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) {
+
+ assert(!ucred);
+ ucred = CMSG_TYPED_DATA(cmsg, struct ucred);
+ }
+
+ if (!ucred)
+ return -EIO;
+
+ *ret_ucred = *ucred;
+
+ return 0;
+}
+
+static int can_forward_coredump(pid_t pid) {
+ _cleanup_free_ char *cgroup = NULL, *path = NULL, *unit = NULL;
+ int r;
+
+ r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &cgroup);
+ if (r < 0)
+ return r;
+
+ r = path_extract_directory(cgroup, &path);
+ if (r < 0)
+ return r;
+
+ r = cg_path_get_unit_path(path, &unit);
+ if (r == -ENOMEM)
+ return log_oom();
+ if (r == -ENXIO)
+ /* No valid units in this path. */
+ return false;
+ if (r < 0)
+ return r;
+
+ /* We require that this process belongs to a delegated cgroup
+ * (i.e. Delegate=yes), with CoredumpReceive=yes also. */
+ r = cg_is_delegated(unit);
+ if (r <= 0)
+ return r;
+
+ return cg_has_coredump_receive(unit);
+}
+
+static int forward_coredump_to_container(Context *context) {
+ _cleanup_close_ int pidnsfd = -EBADF, mntnsfd = -EBADF, netnsfd = -EBADF, usernsfd = -EBADF, rootfd = -EBADF;
+ _cleanup_close_pair_ int pair[2] = PIPE_EBADF;
+ pid_t pid, child;
+ struct ucred ucred = {
+ .pid = context->pid,
+ .uid = context->uid,
+ .gid = context->gid,
+ };
+ int r;
+
+ r = namespace_get_leader(context->pid, NAMESPACE_PID, &pid);
+ if (r < 0)
+ return log_debug_errno(r, "Failed to get namespace leader: %m");
+
+ r = can_forward_coredump(pid);
+ if (r < 0)
+ return log_debug_errno(r, "Failed to check if coredump can be forwarded: %m");
+ if (r == 0)
+ return log_debug_errno(SYNTHETIC_ERRNO(ENOENT),
+ "Coredump will not be forwarded because no target cgroup was found.");
+
+ r = RET_NERRNO(socketpair(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0, pair));
+ if (r < 0)
+ return log_debug_errno(r, "Failed to create socket pair: %m");
+
+ r = setsockopt_int(pair[1], SOL_SOCKET, SO_PASSCRED, true);
+ if (r < 0)
+ return log_debug_errno(r, "Failed to set SO_PASSCRED: %m");
+
+ r = namespace_open(pid, &pidnsfd, &mntnsfd, &netnsfd, &usernsfd, &rootfd);
+ if (r < 0)
+ return log_debug_errno(r, "Failed to join namespaces of PID " PID_FMT ": %m", pid);
+
+ r = namespace_fork("(sd-coredumpns)", "(sd-coredump)", NULL, 0,
+ FORK_RESET_SIGNALS|FORK_DEATHSIG,
+ pidnsfd, mntnsfd, netnsfd, usernsfd, rootfd, &child);
+ if (r < 0)
+ return log_debug_errno(r, "Failed to fork into namespaces of PID " PID_FMT ": %m", pid);
+ if (r == 0) {
+ _cleanup_(iovw_free_freep) struct iovec_wrapper *iovw = NULL;
+ Context child_context = {};
+
+ pair[0] = safe_close(pair[0]);
+
+ if (laccess("/run/systemd/coredump", W_OK) < 0) {
+ log_debug_errno(errno, "Cannot find coredump socket, exiting: %m");
+ _exit(EXIT_FAILURE);
+ }
+
+ r = receive_ucred(pair[1], &ucred);
+ if (r < 0) {
+ log_debug_errno(r, "Failed to receive ucred and fd: %m");
+ _exit(EXIT_FAILURE);
+ }
+
+ iovw = iovw_new();
+ if (!iovw) {
+ log_oom();
+ _exit(EXIT_FAILURE);
+ }
+
+ (void) iovw_put_string_field(iovw, "MESSAGE_ID=", SD_MESSAGE_COREDUMP_STR);
+ (void) iovw_put_string_field(iovw, "PRIORITY=", STRINGIFY(LOG_CRIT));
+ (void) iovw_put_string_field(iovw, "COREDUMP_FORWARDED=", "1");
+
+ for (int i = 0; i < _META_ARGV_MAX; i++) {
+ int signo;
+ char buf[DECIMAL_STR_MAX(pid_t)];
+ const char *t = context->meta[i];
+
+ switch(i) {
+
+ case META_ARGV_PID:
+ xsprintf(buf, PID_FMT, ucred.pid);
+ t = buf;
+
+ break;
+
+ case META_ARGV_UID:
+ xsprintf(buf, UID_FMT, ucred.uid);
+ t = buf;
+ break;
+
+ case META_ARGV_GID:
+ xsprintf(buf, GID_FMT, ucred.gid);
+ t = buf;
+ break;
+
+ case META_ARGV_SIGNAL:
+ if (safe_atoi(t, &signo) >= 0 && SIGNAL_VALID(signo))
+ (void) iovw_put_string_field(iovw,
+ "COREDUMP_SIGNAL_NAME=SIG",
+ signal_to_string(signo));
+ break;
+
+ default:
+ break;
+ }
+
+ r = iovw_put_string_field(iovw, meta_field_names[i], t);
+ if (r < 0) {
+ log_debug_errno(r, "Failed to construct iovec: %m");
+ _exit(EXIT_FAILURE);
+ }
+ }
+
+ r = save_context(&child_context, iovw);
+ if (r < 0) {
+ log_debug_errno(r, "Failed to save context: %m");
+ _exit(EXIT_FAILURE);
+ }
+
+ r = gather_pid_metadata_from_procfs(iovw, &child_context);
+ if (r < 0) {
+ log_debug_errno(r, "Failed to gather metadata from procfs: %m");
+ _exit(EXIT_FAILURE);
+ }
+
+ r = send_iovec(iovw, STDIN_FILENO);
+ if (r < 0) {
+ log_debug_errno(r, "Failed to send iovec to coredump socket: %m");
+ _exit(EXIT_FAILURE);
+ }
+
+ _exit(EXIT_SUCCESS);
+ }
+
+ pair[1] = safe_close(pair[1]);
+
+ /* We need to translate the PID, UID, and GID of the crashing process
+ * to the container's namespaces. Do this by sending an SCM_CREDENTIALS
+ * message on a socket pair, and read the result when we join the
+ * container. The kernel will perform the translation for us. */
+ r = send_ucred(pair[0], &ucred);
+ if (r < 0)
+ return log_debug_errno(r, "Failed to send metadata to container: %m");
+
+ r = wait_for_terminate_and_check("(sd-coredumpns)", child, 0);
+ if (r < 0)
+ return log_debug_errno(r, "Failed to wait for child to terminate: %m");
+ if (r != EXIT_SUCCESS)
+ return log_debug_errno(SYNTHETIC_ERRNO(EPROTO), "Failed to process coredump in container: %m");
+
+ return 0;
+}
+
static int process_kernel(int argc, char* argv[]) {
_cleanup_(iovw_free_freep) struct iovec_wrapper *iovw = NULL;
Context context = {};
if (!iovw)
return log_oom();
- (void) iovw_put_string_field(iovw, "MESSAGE_ID=", SD_MESSAGE_COREDUMP_STR);
- (void) iovw_put_string_field(iovw, "PRIORITY=", STRINGIFY(LOG_CRIT));
-
/* Collect all process metadata passed by the kernel through argv[] */
r = gather_pid_metadata_from_argv(iovw, &context, argc - 1, argv + 1);
if (r < 0)
/* OK, now we know it's not the journal, hence we can make use of it now. */
log_set_target_and_open(LOG_TARGET_JOURNAL_OR_KMSG);
+ r = in_same_namespace(getpid_cached(), context.pid, NAMESPACE_PID);
+ if (r < 0)
+ log_debug_errno(r, "Failed to check pidns of crashing process, ignoring: %m");
+ if (r == 0) {
+ /* If this fails, fallback to the old behavior so that
+ * there is still some record of the crash. */
+ r = forward_coredump_to_container(&context);
+ if (r >= 0)
+ return 0;
+ }
+
/* If this is PID 1 disable coredump collection, we'll unlikely be able to process
* it later on.
*
disable_coredumps();
}
+ (void) iovw_put_string_field(iovw, "MESSAGE_ID=", SD_MESSAGE_COREDUMP_STR);
+ (void) iovw_put_string_field(iovw, "PRIORITY=", STRINGIFY(LOG_CRIT));
+
if (context.is_journald || context.is_pid1)
return submit_coredump(&context, iovw, STDIN_FILENO);
projects / thirdparty / systemd.git / commitdiff
