151 lines
3.7 KiB
C
151 lines
3.7 KiB
C
#include <assert.h>
|
|
#include <signal.h>
|
|
#include <stdlib.h>
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
#include <sys/socket.h>
|
|
#include <sys/types.h>
|
|
#include <sys/wait.h>
|
|
#include <unistd.h>
|
|
|
|
#include "buf.h"
|
|
#include "list.h"
|
|
#include "peer.h"
|
|
#include "uuid.h"
|
|
#include "wakeup.h"
|
|
|
|
#include "exec.h"
|
|
|
|
struct exec {
|
|
struct peer peer;
|
|
uint8_t id[UUID_LEN];
|
|
char *command;
|
|
exec_connection_handler handler;
|
|
exec_get_hello hello;
|
|
void *passthrough;
|
|
uint32_t *count;
|
|
pid_t child;
|
|
struct list_head exec_list;
|
|
};
|
|
|
|
static struct list_head exec_head = LIST_HEAD_INIT(exec_head);
|
|
|
|
static void exec_spawn_wrapper(struct peer *);
|
|
|
|
static void exec_del(struct exec *exec) {
|
|
(*exec->count)--;
|
|
if (exec->child > 0) {
|
|
fprintf(stderr, "E %s: Sending SIGTERM to child process %d\n", exec->id, exec->child);
|
|
// Racy with the process terminating, so don't assert on it
|
|
kill(exec->child, SIGTERM);
|
|
assert(waitpid(exec->child, NULL, 0) == exec->child);
|
|
}
|
|
free(exec->command);
|
|
free(exec);
|
|
}
|
|
|
|
static void exec_close_handler(struct peer *peer) {
|
|
struct exec *exec = (struct exec *) peer;
|
|
int status;
|
|
assert(waitpid(exec->child, &status, WNOHANG) == exec->child);
|
|
exec->child = -1;
|
|
if (WIFEXITED(status)) {
|
|
fprintf(stderr, "E %s: Client exited with status %d\n", exec->id, WEXITSTATUS(status));
|
|
} else {
|
|
assert(WIFSIGNALED(status));
|
|
fprintf(stderr, "E %s: Client exited with signal %d\n", exec->id, WTERMSIG(status));
|
|
}
|
|
uint32_t delay = wakeup_get_retry_delay_ms(1);
|
|
fprintf(stderr, "E %s: Will retry in %ds\n", exec->id, delay / 1000);
|
|
exec->peer.event_handler = exec_spawn_wrapper;
|
|
wakeup_add((struct peer *) exec, delay);
|
|
}
|
|
|
|
static bool exec_hello(int fd, struct exec *exec) {
|
|
if (!exec->hello) {
|
|
return true;
|
|
}
|
|
struct buf buf = BUF_INIT, *buf_ptr = &buf;
|
|
exec->hello(&buf_ptr, exec->passthrough);
|
|
if (!buf_ptr->length) {
|
|
return true;
|
|
}
|
|
return (write(fd, buf_at(buf_ptr, 0), buf_ptr->length) == (ssize_t) buf_ptr->length);
|
|
}
|
|
|
|
static void exec_parent(struct exec *exec, pid_t child, int fd) {
|
|
exec->child = child;
|
|
fprintf(stderr, "E %s: Child started as process %d\n", exec->id, exec->child);
|
|
|
|
if (!exec_hello(fd, exec)) {
|
|
assert(!close(fd));
|
|
exec_close_handler((struct peer *) exec);
|
|
return;
|
|
}
|
|
|
|
exec->peer.event_handler = exec_close_handler;
|
|
exec->handler(fd, exec->passthrough, (struct peer *) exec);
|
|
}
|
|
|
|
static void __attribute__ ((noreturn)) exec_child(const struct exec *exec, int fd) {
|
|
assert(setsid() != -1);
|
|
// We leave stderr open from child to parent
|
|
// Other than that, fds should have CLOEXEC set
|
|
if (fd != 0) {
|
|
assert(dup2(fd, 0) == 0);
|
|
}
|
|
if (fd != 1) {
|
|
assert(dup2(fd, 1) == 1);
|
|
}
|
|
if (fd != 0 && fd != 1) {
|
|
assert(!close(fd));
|
|
}
|
|
assert(!execl("/bin/sh", "sh", "-c", exec->command, NULL));
|
|
abort();
|
|
}
|
|
|
|
static void exec_spawn(struct exec *exec) {
|
|
fprintf(stderr, "E %s: Executing: %s\n", exec->id, exec->command);
|
|
int fds[2];
|
|
assert(!socketpair(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK, 0, fds));
|
|
|
|
int res = fork();
|
|
assert(res >= 0);
|
|
if (res) {
|
|
assert(!close(fds[1]));
|
|
exec_parent(exec, res, fds[0]);
|
|
} else {
|
|
assert(!close(fds[0]));
|
|
exec_child(exec, fds[1]);
|
|
}
|
|
}
|
|
|
|
static void exec_spawn_wrapper(struct peer *peer) {
|
|
struct exec *exec = (struct exec *) peer;
|
|
exec_spawn(exec);
|
|
}
|
|
|
|
void exec_cleanup() {
|
|
struct exec *iter, *next;
|
|
list_for_each_entry_safe(iter, next, &exec_head, exec_list) {
|
|
exec_del(iter);
|
|
}
|
|
}
|
|
|
|
void exec_new(char *command, exec_connection_handler handler, exec_get_hello hello, void *passthrough, uint32_t *count) {
|
|
(*count)++;
|
|
|
|
struct exec *exec = malloc(sizeof(*exec));
|
|
exec->peer.fd = -1;
|
|
uuid_gen(exec->id);
|
|
exec->command = strdup(command);
|
|
exec->handler = handler;
|
|
exec->hello = hello;
|
|
exec->passthrough = passthrough;
|
|
exec->count = count;
|
|
|
|
list_add(&exec->exec_list, &exec_head);
|
|
|
|
exec_spawn(exec);
|
|
}
|