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serialize: add new helper deserialize_fd()

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Currently, when we deserialize an fd we do a lot of manual work. Add a
common helper that makes this more robust and uniform.

Note that this sometimes changes behaviour slightly, but in ways that
shouldn't really matter: if we fail to deserialize an fd correctly we'll
unset (i.e. set to -EBADF) the fd in the deserialized data structure.
Previously, we'd leave the old value in place.

This should not change effective result (as in either case we'll be in a
bad state afterwards, just once we mix old/invalidated state with new
state, while now we'll reset the state explicitly to invalidated state
on failure). In particular as deserialization starts from an empty
structure generally, hence the old value should be unset anyway.

Another slight change is that if we fail to deserialize some object half
way, and we already have taken out one fd from the serialized fdset
we'll now just close it instead of returning it to/leaving it in the
fdset. Given that such "orphaned" fds are blanket closed after
deserialization finishes this also shouldn't change behaviour IRL.

Also, the idle_pipe was previously incorrectly serialized: we'd
serialize invalidated fds, which would fail, but because parsing errors
on this were ignored on the deserializatin noone noticed. This is fixed.
This commit is contained in:
Lennart Poettering
2023-10-18 12:54:20 +02:00
parent 87a768b801
commit dff9808a62
9 changed files with 157 additions and 265 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/core/execute-serialize.c
+65 -123
View File
@@ -1232,17 +1232,11 @@ static int exec_runtime_deserialize(ExecRuntime *rt, FILE *f, FDSet *fds) {
if (r == 0)
break;
if ((fd = parse_fd(w)) < 0 || !fdset_contains(fds, fd))
log_debug("Failed to parse %s value: %s, ignoring.", l, w);
else {
r = fdset_remove(fds, fd);
if (r < 0) {
log_debug_errno(r, "Failed to remove %s value=%d from fdset, ignoring: %m", l, fd);
continue;
}
fd = deserialize_fd(fds, w);
if (fd < 0)
continue;
rt->shared->netns_storage_socket[i] = fd;
}
rt->shared->netns_storage_socket[i] = fd;
}
} else if ((val = startswith(l, "exec-runtime-ipcns-storage-socket="))) {
for (size_t i = 0; i < 2; ++i) {
@@ -1255,17 +1249,11 @@ static int exec_runtime_deserialize(ExecRuntime *rt, FILE *f, FDSet *fds) {
if (r == 0)
break;
if ((fd = parse_fd(w)) < 0 || !fdset_contains(fds, fd))
log_debug("Failed to parse %s value: %s, ignoring.", l, w);
else {
r = fdset_remove(fds, fd);
if (r < 0) {
log_debug_errno(r, "Failed to remove %s value=%d from fdset, ignoring: %m", l, fd);
continue;
}
fd = deserialize_fd(fds, w);
if (fd < 0)
continue;
rt->shared->ipcns_storage_socket[i] = fd;
}
rt->shared->ipcns_storage_socket[i] = fd;
}
} else if ((val = startswith(l, "exec-runtime-dynamic-creds-user=")))
dynamic_user_deserialize_one(/* m= */ NULL, val, fds, &rt->dynamic_creds->user);
@@ -1297,17 +1285,11 @@ static int exec_runtime_deserialize(ExecRuntime *rt, FILE *f, FDSet *fds) {
if (r == 0)
break;
if ((fd = parse_fd(w)) < 0 || !fdset_contains(fds, fd))
log_debug("Failed to parse %s value: %s, ignoring.", l, w);
else {
r = fdset_remove(fds, fd);
if (r < 0) {
log_debug_errno(r, "Failed to remove %s value=%d from fdset, ignoring: %m", l, fd);
continue;
}
fd = deserialize_fd(fds, w);
if (fd < 0)
continue;
rt->ephemeral_storage_socket[i] = fd;
}
rt->ephemeral_storage_socket[i] = fd;
}
} else
log_warning("Failed to parse serialized line, ignoring: %s", l);
@@ -1316,6 +1298,16 @@ static int exec_runtime_deserialize(ExecRuntime *rt, FILE *f, FDSet *fds) {
return 0;
}
static bool exec_parameters_is_idle_pipe_set(const ExecParameters *p) {
assert(p);
return p->idle_pipe &&
p->idle_pipe[0] >= 0 &&
p->idle_pipe[1] >= 0 &&
p->idle_pipe[2] >= 0 &&
p->idle_pipe[3] >= 0;
}
static int exec_parameters_serialize(const ExecParameters *p, FILE *f, FDSet *fds) {
int r;
@@ -1434,17 +1426,13 @@ static int exec_parameters_serialize(const ExecParameters *p, FILE *f, FDSet *fd
return r;
}
if (p->idle_pipe) {
if (exec_parameters_is_idle_pipe_set(p)) {
_cleanup_free_ char *serialized_fds = NULL;
for (size_t i = 0; i < 4; ++i) {
int copy = -EBADF;
if (p->idle_pipe[i] >= 0) {
copy = fdset_put_dup(fds, p->idle_pipe[i]);
if (copy < 0)
return copy;
}
int copy = fdset_put_dup(fds, p->idle_pipe[i]);
if (copy < 0)
return copy;
r = strextendf(&serialized_fds, "%d ", copy);
if (r < 0)
@@ -1609,17 +1597,11 @@ static int exec_parameters_deserialize(ExecParameters *p, FILE *f, FDSet *fds) {
if (r == 0)
break;
if ((fd = parse_fd(w)) < 0 || !fdset_contains(fds, fd))
log_debug("Failed to parse %s value: %s, ignoring.", l, w);
else {
r = fdset_remove(fds, fd);
if (r < 0) {
log_debug_errno(r, "Failed to remove %s value=%d from fdset, ignoring: %m", l, fd);
continue;
}
fd = deserialize_fd(fds, w);
if (fd < 0)
continue;
p->fds[i] = fd;
}
p->fds[i] = fd;
}
} else if ((val = startswith(l, "exec-parameters-fd-names="))) {
r = deserialize_strv(&p->fd_names, val);
@@ -1719,94 +1701,60 @@ static int exec_parameters_deserialize(ExecParameters *p, FILE *f, FDSet *fds) {
if (r == 0)
break;
if ((fd = parse_fd(w)) < 0 || !fdset_contains(fds, fd))
log_debug("Failed to parse %s value: %s, ignoring.", l, w);
else {
r = fdset_remove(fds, fd);
if (r < 0) {
log_debug_errno(r, "Failed to remove %s value=%d from fdset, ignoring: %m", l, fd);
continue;
}
fd = deserialize_fd(fds, w);
if (fd < 0)
continue;
p->idle_pipe[i] = fd;
}
p->idle_pipe[i] = fd;
}
} else if ((val = startswith(l, "exec-parameters-stdin-fd="))) {
int fd;
if ((fd = parse_fd(val)) < 0 || !fdset_contains(fds, fd))
log_debug("Failed to parse %s value: %s, ignoring.", l, val);
else {
r = fdset_remove(fds, fd);
if (r < 0) {
log_debug_errno(r, "Failed to remove %s value=%d from fdset, ignoring: %m", l, fd);
continue;
}
fd = deserialize_fd(fds, val);
if (fd < 0)
continue;
p->stdin_fd = fd;
p->stdin_fd = fd;
}
} else if ((val = startswith(l, "exec-parameters-stdout-fd="))) {
int fd;
if ((fd = parse_fd(val)) < 0 || !fdset_contains(fds, fd))
log_debug("Failed to parse %s value: %s, ignoring.", l, val);
else {
r = fdset_remove(fds, fd);
if (r < 0) {
log_debug_errno(r, "Failed to remove %s value=%d from fdset, ignoring: %m", l, fd);
continue;
}
fd = deserialize_fd(fds, val);
if (fd < 0)
continue;
p->stdout_fd = fd;
p->stdout_fd = fd;
}
} else if ((val = startswith(l, "exec-parameters-stderr-fd="))) {
int fd;
if ((fd = parse_fd(val)) < 0 || !fdset_contains(fds, fd))
log_debug("Failed to parse %s value: %s, ignoring.", l, val);
else {
r = fdset_remove(fds, fd);
if (r < 0) {
log_debug_errno(r, "Failed to remove %s value=%d from fdset, ignoring: %m", l, fd);
continue;
}
fd = deserialize_fd(fds, val);
if (fd < 0)
continue;
p->stderr_fd = fd;
}
p->stderr_fd = fd;
} else if ((val = startswith(l, "exec-parameters-exec-fd="))) {
int fd;
if ((fd = parse_fd(val)) < 0 || !fdset_contains(fds, fd))
log_debug("Failed to parse %s value: %s, ignoring.", l, val);
else {
r = fdset_remove(fds, fd);
if (r < 0) {
log_debug_errno(r, "Failed to remove %s value=%d from fdset, ignoring: %m", l, fd);
continue;
}
fd = deserialize_fd(fds, val);
if (fd < 0)
continue;
/* This is special and relies on close-on-exec semantics, make sure it's
* there */
r = fd_cloexec(fd, true);
if (r < 0)
return r;
/* This is special and relies on close-on-exec semantics, make sure it's
* there */
r = fd_cloexec(fd, true);
if (r < 0)
return r;
p->exec_fd = fd;
}
p->exec_fd = fd;
} else if ((val = startswith(l, "exec-parameters-bpf-outer-map-fd="))) {
int fd;
if ((fd = parse_fd(val)) < 0 || !fdset_contains(fds, fd))
log_debug("Failed to parse %s value: %s, ignoring.", l, val);
else {
r = fdset_remove(fds, fd);
if (r < 0) {
log_debug_errno(r, "Failed to remove %s value=%d from fdset, ignoring: %m", l, fd);
continue;
}
fd = deserialize_fd(fds, val);
if (fd < 0)
continue;
p->bpf_outer_map_fd = fd;
}
p->bpf_outer_map_fd = fd;
} else if ((val = startswith(l, "exec-parameters-notify-socket="))) {
r = free_and_strdup(&p->notify_socket, val);
if (r < 0)
@@ -1826,17 +1774,11 @@ static int exec_parameters_deserialize(ExecParameters *p, FILE *f, FDSet *fds) {
} else if ((val = startswith(l, "exec-parameters-user-lookup-fd="))) {
int fd;
if ((fd = parse_fd(val)) < 0 || !fdset_contains(fds, fd))
log_debug("Failed to parse %s value: %s, ignoring.", l, val);
else {
r = fdset_remove(fds, fd);
if (r < 0) {
log_debug_errno(r, "Failed to remove %s value=%d from fdset, ignoring: %m", l, fd);
continue;
}
fd = deserialize_fd(fds, val);
if (fd < 0)
continue;
p->user_lookup_fd = fd;
}
p->user_lookup_fd = fd;
} else if ((val = startswith(l, "exec-parameters-files-env="))) {
r = deserialize_strv(&p->files_env, val);
if (r < 0)