SymbX/systemd
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

core/exec: add a named-descriptor option ("fd") for streams (#4179)

Browse Source 
This commit adds a `fd` option to `StandardInput=`,
`StandardOutput=` and `StandardError=` properties in order to
connect standard streams to externally named descriptors provided
by some socket units.

This option looks for a file descriptor named as the corresponding
stream. Custom names can be specified, separated by a colon.
If multiple name-matches exist, the first matching fd will be used.
This commit is contained in:
Luca Bruno
2016-10-17 20:05:49 -04:00
committed by Zbigniew Jędrzejewski-Szmek
parent c7458f9399
commit 52c239d770
8 changed files with 322 additions and 33 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/core/execute.c
+79 -7
View File
@@ -411,7 +411,8 @@ static int fixup_output(ExecOutput std_output, int socket_fd) {
static int setup_input(
const ExecContext *context,
const ExecParameters *params,
int socket_fd) {
int socket_fd,
int named_iofds[3]) {
ExecInput i;
@@ -461,6 +462,10 @@ static int setup_input(
case EXEC_INPUT_SOCKET:
return dup2(socket_fd, STDIN_FILENO) < 0 ? -errno : STDIN_FILENO;
case EXEC_INPUT_NAMED_FD:
(void) fd_nonblock(named_iofds[STDIN_FILENO], false);
return dup2(named_iofds[STDIN_FILENO], STDIN_FILENO) < 0 ? -errno : STDIN_FILENO;
default:
assert_not_reached("Unknown input type");
}
@@ -472,6 +477,7 @@ static int setup_output(
const ExecParameters *params,
int fileno,
int socket_fd,
int named_iofds[3],
const char *ident,
uid_t uid,
gid_t gid,
@@ -523,7 +529,7 @@ static int setup_output(
return fileno;
/* Duplicate from stdout if possible */
if (e == o || e == EXEC_OUTPUT_INHERIT)
if ((e == o && e != EXEC_OUTPUT_NAMED_FD) || e == EXEC_OUTPUT_INHERIT)
return dup2(STDOUT_FILENO, fileno) < 0 ? -errno : fileno;
o = e;
@@ -585,6 +591,10 @@ static int setup_output(
assert(socket_fd >= 0);
return dup2(socket_fd, fileno) < 0 ? -errno : fileno;
case EXEC_OUTPUT_NAMED_FD:
(void) fd_nonblock(named_iofds[fileno], false);
return dup2(named_iofds[fileno], fileno) < 0 ? -errno : fileno;
default:
assert_not_reached("Unknown error type");
}
@@ -2157,6 +2167,7 @@ static int exec_child(
DynamicCreds *dcreds,
char **argv,
int socket_fd,
int named_iofds[3],
int *fds, unsigned n_fds,
char **files_env,
int user_lookup_fd,
@@ -2298,19 +2309,19 @@ static int exec_child(
if (socket_fd >= 0)
(void) fd_nonblock(socket_fd, false);
r = setup_input(context, params, socket_fd);
r = setup_input(context, params, socket_fd, named_iofds);
if (r < 0) {
*exit_status = EXIT_STDIN;
return r;
}
r = setup_output(unit, context, params, STDOUT_FILENO, socket_fd, basename(command->path), uid, gid, &journal_stream_dev, &journal_stream_ino);
r = setup_output(unit, context, params, STDOUT_FILENO, socket_fd, named_iofds, basename(command->path), uid, gid, &journal_stream_dev, &journal_stream_ino);
if (r < 0) {
*exit_status = EXIT_STDOUT;
return r;
}
r = setup_output(unit, context, params, STDERR_FILENO, socket_fd, basename(command->path), uid, gid, &journal_stream_dev, &journal_stream_ino);
r = setup_output(unit, context, params, STDERR_FILENO, socket_fd, named_iofds, basename(command->path), uid, gid, &journal_stream_dev, &journal_stream_ino);
if (r < 0) {
*exit_status = EXIT_STDERR;
return r;
@@ -2829,6 +2840,7 @@ int exec_spawn(Unit *unit,
int *fds = NULL; unsigned n_fds = 0;
_cleanup_free_ char *line = NULL;
int socket_fd, r;
int named_iofds[3] = { -1, -1, -1 };
char **argv;
pid_t pid;
@@ -2855,6 +2867,10 @@ int exec_spawn(Unit *unit,
n_fds = params->n_fds;
}
r = exec_context_named_iofds(unit, context, params, named_iofds);
if (r < 0)
return log_unit_error_errno(unit, r, "Failed to load a named file descriptor: %m");
r = exec_context_load_environment(unit, context, &files_env);
if (r < 0)
return log_unit_error_errno(unit, r, "Failed to load environment files: %m");
@@ -2884,6 +2900,7 @@ int exec_spawn(Unit *unit,
dcreds,
argv,
socket_fd,
named_iofds,
fds, n_fds,
files_env,
unit->manager->user_lookup_fds[1],
@@ -2946,6 +2963,9 @@ void exec_context_done(ExecContext *c) {
for (l = 0; l < ELEMENTSOF(c->rlimit); l++)
c->rlimit[l] = mfree(c->rlimit[l]);
for (l = 0; l < 3; l++)
c->stdio_fdname[l] = mfree(c->stdio_fdname[l]);
c->working_directory = mfree(c->working_directory);
c->root_directory = mfree(c->root_directory);
c->tty_path = mfree(c->tty_path);
@@ -3044,6 +3064,56 @@ static void invalid_env(const char *p, void *userdata) {
log_unit_error(info->unit, "Ignoring invalid environment assignment '%s': %s", p, info->path);
}
const char* exec_context_fdname(const ExecContext *c, int fd_index) {
assert(c);
switch (fd_index) {
case STDIN_FILENO:
if (c->std_input != EXEC_INPUT_NAMED_FD)
return NULL;
return c->stdio_fdname[STDIN_FILENO] ?: "stdin";
case STDOUT_FILENO:
if (c->std_output != EXEC_OUTPUT_NAMED_FD)
return NULL;
return c->stdio_fdname[STDOUT_FILENO] ?: "stdout";
case STDERR_FILENO:
if (c->std_error != EXEC_OUTPUT_NAMED_FD)
return NULL;
return c->stdio_fdname[STDERR_FILENO] ?: "stderr";
default:
return NULL;
}
}
int exec_context_named_iofds(Unit *unit, const ExecContext *c, const ExecParameters *p, int named_iofds[3]) {
unsigned i, targets;
const char *stdio_fdname[3];
assert(c);
assert(p);
targets = (c->std_input == EXEC_INPUT_NAMED_FD) +
(c->std_output == EXEC_OUTPUT_NAMED_FD) +
(c->std_error == EXEC_OUTPUT_NAMED_FD);
for (i = 0; i < 3; i++)
stdio_fdname[i] = exec_context_fdname(c, i);
for (i = 0; i < p->n_fds && targets > 0; i++)
if (named_iofds[STDIN_FILENO] < 0 && c->std_input == EXEC_INPUT_NAMED_FD && stdio_fdname[STDIN_FILENO] && streq(p->fd_names[i], stdio_fdname[STDIN_FILENO])) {
named_iofds[STDIN_FILENO] = p->fds[i];
targets--;
} else if (named_iofds[STDOUT_FILENO] < 0 && c->std_output == EXEC_OUTPUT_NAMED_FD && stdio_fdname[STDOUT_FILENO] && streq(p->fd_names[i], stdio_fdname[STDOUT_FILENO])) {
named_iofds[STDOUT_FILENO] = p->fds[i];
targets--;
} else if (named_iofds[STDERR_FILENO] < 0 && c->std_error == EXEC_OUTPUT_NAMED_FD && stdio_fdname[STDERR_FILENO] && streq(p->fd_names[i], stdio_fdname[STDERR_FILENO])) {
named_iofds[STDERR_FILENO] = p->fds[i];
targets--;
}
return (targets == 0 ? 0 : -ENOENT);
}
int exec_context_load_environment(Unit *unit, const ExecContext *c, char ***l) {
char **i, **r = NULL;
@@ -3896,7 +3966,8 @@ static const char* const exec_input_table[_EXEC_INPUT_MAX] = {
[EXEC_INPUT_TTY] = "tty",
[EXEC_INPUT_TTY_FORCE] = "tty-force",
[EXEC_INPUT_TTY_FAIL] = "tty-fail",
[EXEC_INPUT_SOCKET] = "socket"
[EXEC_INPUT_SOCKET] = "socket",
[EXEC_INPUT_NAMED_FD] = "fd",
};
DEFINE_STRING_TABLE_LOOKUP(exec_input, ExecInput);
@@ -3911,7 +3982,8 @@ static const char* const exec_output_table[_EXEC_OUTPUT_MAX] = {
[EXEC_OUTPUT_KMSG_AND_CONSOLE] = "kmsg+console",
[EXEC_OUTPUT_JOURNAL] = "journal",
[EXEC_OUTPUT_JOURNAL_AND_CONSOLE] = "journal+console",
[EXEC_OUTPUT_SOCKET] = "socket"
[EXEC_OUTPUT_SOCKET] = "socket",
[EXEC_OUTPUT_NAMED_FD] = "fd",
};
DEFINE_STRING_TABLE_LOOKUP(exec_output, ExecOutput);