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coredump: split out process_socket() to coredump-receive.[ch]

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Then, rename to coredump_receive().
This commit is contained in:
Yu Watanabe
2025-10-19 10:01:38 +09:00
parent 640b7c38f8
commit ab2e98b43c
5 changed files with 170 additions and 152 deletions
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src/coredump/coredump-context.c
+1 -1
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@@ -275,7 +275,7 @@ int context_parse_iovw(Context *context, struct iovec_wrapper *iovw) {
bool have_signal_name = false;
FOREACH_ARRAY(iovec, iovw->iovec, iovw->count) {
/* 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 process_socket() and
* is in the buffer, though not included in the iov_len count. See coredump_receive() and
* gather_pid_metadata_*(). */
assert(((char*) iovec->iov_base)[iovec->iov_len] == 0);
src/coredump/coredump-receive.c
+162
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@@ -0,0 +1,162 @@
/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include <stdlib.h>
#include "coredump-context.h"
#include "coredump-receive.h"
#include "coredump-submit.h"
#include "iovec-util.h"
#include "iovec-wrapper.h"
#include "fd-util.h"
#include "log.h"
#include "socket-util.h"
int coredump_receive(int fd) {
_cleanup_(iovw_done_free) struct iovec_wrapper iovw = {};
_cleanup_(context_done) Context context = CONTEXT_NULL;
_cleanup_close_ int input_fd = -EBADF;
enum {
STATE_PAYLOAD,
STATE_INPUT_FD_DONE,
STATE_PID_FD_DONE,
} state = STATE_PAYLOAD;
int r;
assert(fd >= 0);
log_setup();
log_debug("Processing coredump received via socket...");
for (;;) {
CMSG_BUFFER_TYPE(CMSG_SPACE(sizeof(int))) control;
struct msghdr mh = {
.msg_control = &control,
.msg_controllen = sizeof(control),
.msg_iovlen = 1,
};
ssize_t n, l;
l = next_datagram_size_fd(fd);
if (l < 0)
return log_error_errno(l, "Failed to determine datagram size to read: %m");
_cleanup_(iovec_done) struct iovec iovec = {
.iov_len = l,
.iov_base = malloc(l + 1),
};
if (!iovec.iov_base)
return log_oom();
mh.msg_iov = &iovec;
n = recvmsg_safe(fd, &mh, MSG_CMSG_CLOEXEC);
if (n < 0)
return log_error_errno(n, "Failed to receive datagram: %m");
/* The final zero-length datagrams ("sentinels") carry file descriptors and tell us that
* we're done. There are three sentinels: one with just the coredump fd, followed by one with
* the pidfd, and finally one with the mount tree fd. The latter two or the last one may be
* omitted (which is supported for compatibility with older systemd version, in particular to
* facilitate cross-container coredumping). */
if (n == 0) {
struct cmsghdr *found;
found = cmsg_find(&mh, SOL_SOCKET, SCM_RIGHTS, CMSG_LEN(sizeof(int)));
if (!found) {
/* This is zero length message but it either doesn't carry a single
* descriptor, or it has more than one. This is a protocol violation so let's
* bail out.
*
* Well, not quite! In practice there's one more complication: EOF on
* SOCK_SEQPACKET is not distinguishable from a zero length datagram. Hence
* if we get a zero length datagram without fds we consider it EOF, and
* that's permissible for the final two fds. Hence let's be strict on the
* first fd, but lenient on the other two. */
if (!cmsg_find(&mh, SOL_SOCKET, SCM_RIGHTS, (socklen_t) -1) && state != STATE_PAYLOAD)
/* No fds, and already got the first fd → we are done. */
break;
cmsg_close_all(&mh);
return log_error_errno(SYNTHETIC_ERRNO(EBADMSG),
"Received zero length message with zero or more than one file descriptor(s), expected one.");
}
switch (state) {
case STATE_PAYLOAD:
assert(input_fd < 0);
input_fd = *CMSG_TYPED_DATA(found, int);
state = STATE_INPUT_FD_DONE;
continue;
case STATE_INPUT_FD_DONE:
assert(!pidref_is_set(&context.pidref));
r = pidref_set_pidfd_consume(&context.pidref, *CMSG_TYPED_DATA(found, int));
if (r < 0)
return log_error_errno(r, "Failed to initialize pidref: %m");
state = STATE_PID_FD_DONE;
continue;
case STATE_PID_FD_DONE:
assert(context.mount_tree_fd < 0);
context.mount_tree_fd = *CMSG_TYPED_DATA(found, int);
/* We have all FDs we need so we are done. */
break;
}
break;
}
cmsg_close_all(&mh);
/* Only zero length messages are allowed after the first message that carried a file descriptor. */
if (state != STATE_PAYLOAD)
return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "Received unexpected message with non-zero length.");
/* Payload messages should not carry fds */
if (cmsg_find(&mh, SOL_SOCKET, SCM_RIGHTS, (socklen_t) -1))
return log_error_errno(SYNTHETIC_ERRNO(EBADMSG),
"Received payload message with file descriptor(s), expected none.");
/* Add trailing NUL byte, in case these are strings */
((char*) iovec.iov_base)[n] = 0;
iovec.iov_len = (size_t) n;
if (iovw_put(&iovw, iovec.iov_base, iovec.iov_len) < 0)
return log_oom();
TAKE_STRUCT(iovec);
}
/* Make sure we got all data we really need */
assert(input_fd >= 0);
r = context_parse_iovw(&context, &iovw);
if (r < 0)
return r;
/* Make sure we received all the expected fields. We support being called by an *older*
* systemd-coredump from the outside, so we require only the basic set of fields that
* was being sent when the support for sending to containers over a socket was added
* in a108c43e36d3ceb6e34efe37c014fc2cda856000. */
meta_argv_t i;
FOREACH_ARGUMENT(i,
META_ARGV_PID,
META_ARGV_UID,
META_ARGV_GID,
META_ARGV_SIGNAL,
META_ARGV_TIMESTAMP,
META_ARGV_RLIMIT,
META_ARGV_HOSTNAME,
META_COMM)
if (!context.meta[i])
return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
"Mandatory argument %s not received on socket, aborting.",
meta_field_names[i]);
return coredump_submit(&context, &iovw, input_fd);
}
src/coredump/coredump-receive.h
+4
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@@ -0,0 +1,4 @@
/* SPDX-License-Identifier: LGPL-2.1-or-later */
#pragma once
int coredump_receive(int fd);
src/coredump/coredump.c
+2 -151
View File
@@ -25,6 +25,7 @@
#include "coredump-backtrace.h"
#include "coredump-config.h"
#include "coredump-context.h"
#include "coredump-receive.h"
#include "coredump-submit.h"
#include "coredump-util.h"
#include "coredump-vacuum.h"
@@ -60,156 +61,6 @@
#include "uid-classification.h"
#include "user-util.h"
static int process_socket(int fd) {
_cleanup_(iovw_done_free) struct iovec_wrapper iovw = {};
_cleanup_(context_done) Context context = CONTEXT_NULL;
_cleanup_close_ int input_fd = -EBADF;
enum {
STATE_PAYLOAD,
STATE_INPUT_FD_DONE,
STATE_PID_FD_DONE,
} state = STATE_PAYLOAD;
int r;
assert(fd >= 0);
log_setup();
log_debug("Processing coredump received via socket...");
for (;;) {
CMSG_BUFFER_TYPE(CMSG_SPACE(sizeof(int))) control;
struct msghdr mh = {
.msg_control = &control,
.msg_controllen = sizeof(control),
.msg_iovlen = 1,
};
ssize_t n, l;
l = next_datagram_size_fd(fd);
if (l < 0)
return log_error_errno(l, "Failed to determine datagram size to read: %m");
_cleanup_(iovec_done) struct iovec iovec = {
.iov_len = l,
.iov_base = malloc(l + 1),
};
if (!iovec.iov_base)
return log_oom();
mh.msg_iov = &iovec;
n = recvmsg_safe(fd, &mh, MSG_CMSG_CLOEXEC);
if (n < 0)
return log_error_errno(n, "Failed to receive datagram: %m");
/* The final zero-length datagrams ("sentinels") carry file descriptors and tell us that
* we're done. There are three sentinels: one with just the coredump fd, followed by one with
* the pidfd, and finally one with the mount tree fd. The latter two or the last one may be
* omitted (which is supported for compatibility with older systemd version, in particular to
* facilitate cross-container coredumping). */
if (n == 0) {
struct cmsghdr *found;
found = cmsg_find(&mh, SOL_SOCKET, SCM_RIGHTS, CMSG_LEN(sizeof(int)));
if (!found) {
/* This is zero length message but it either doesn't carry a single
* descriptor, or it has more than one. This is a protocol violation so let's
* bail out.
*
* Well, not quite! In practice there's one more complication: EOF on
* SOCK_SEQPACKET is not distinguishable from a zero length datagram. Hence
* if we get a zero length datagram without fds we consider it EOF, and
* that's permissible for the final two fds. Hence let's be strict on the
* first fd, but lenient on the other two. */
if (!cmsg_find(&mh, SOL_SOCKET, SCM_RIGHTS, (socklen_t) -1) && state != STATE_PAYLOAD)
/* No fds, and already got the first fd → we are done. */
break;
cmsg_close_all(&mh);
return log_error_errno(SYNTHETIC_ERRNO(EBADMSG),
"Received zero length message with zero or more than one file descriptor(s), expected one.");
}
switch (state) {
case STATE_PAYLOAD:
assert(input_fd < 0);
input_fd = *CMSG_TYPED_DATA(found, int);
state = STATE_INPUT_FD_DONE;
continue;
case STATE_INPUT_FD_DONE:
assert(!pidref_is_set(&context.pidref));
r = pidref_set_pidfd_consume(&context.pidref, *CMSG_TYPED_DATA(found, int));
if (r < 0)
return log_error_errno(r, "Failed to initialize pidref: %m");
state = STATE_PID_FD_DONE;
continue;
case STATE_PID_FD_DONE:
assert(context.mount_tree_fd < 0);
context.mount_tree_fd = *CMSG_TYPED_DATA(found, int);
/* We have all FDs we need so we are done. */
break;
}
break;
}
cmsg_close_all(&mh);
/* Only zero length messages are allowed after the first message that carried a file descriptor. */
if (state != STATE_PAYLOAD)
return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "Received unexpected message with non-zero length.");
/* Payload messages should not carry fds */
if (cmsg_find(&mh, SOL_SOCKET, SCM_RIGHTS, (socklen_t) -1))
return log_error_errno(SYNTHETIC_ERRNO(EBADMSG),
"Received payload message with file descriptor(s), expected none.");
/* Add trailing NUL byte, in case these are strings */
((char*) iovec.iov_base)[n] = 0;
iovec.iov_len = (size_t) n;
if (iovw_put(&iovw, iovec.iov_base, iovec.iov_len) < 0)
return log_oom();
TAKE_STRUCT(iovec);
}
/* Make sure we got all data we really need */
assert(input_fd >= 0);
r = context_parse_iovw(&context, &iovw);
if (r < 0)
return r;
/* Make sure we received all the expected fields. We support being called by an *older*
* systemd-coredump from the outside, so we require only the basic set of fields that
* was being sent when the support for sending to containers over a socket was added
* in a108c43e36d3ceb6e34efe37c014fc2cda856000. */
meta_argv_t i;
FOREACH_ARGUMENT(i,
META_ARGV_PID,
META_ARGV_UID,
META_ARGV_GID,
META_ARGV_SIGNAL,
META_ARGV_TIMESTAMP,
META_ARGV_RLIMIT,
META_ARGV_HOSTNAME,
META_COMM)
if (!context.meta[i])
return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
"Mandatory argument %s not received on socket, aborting.",
meta_field_names[i]);
return coredump_submit(&context, &iovw, input_fd);
}
static int send_iovec(const struct iovec_wrapper *iovw, int input_fd, PidRef *pidref, int mount_tree_fd) {
_cleanup_close_ int fd = -EBADF;
int r;
@@ -624,7 +475,7 @@ static int run(int argc, char *argv[]) {
else
return process_kernel(argc, argv);
} else if (r == 1)
return process_socket(SD_LISTEN_FDS_START);
return coredump_receive(SD_LISTEN_FDS_START);
return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
"Received unexpected number of file descriptors.");
src/coredump/meson.build
+1
View File
@@ -9,6 +9,7 @@ systemd_coredump_sources = files(
'coredump-backtrace.c',
'coredump-config.c',
'coredump-context.c',
'coredump-receive.c',
'coredump-submit.c',
)
systemd_coredump_extract_sources = files(