FILE *dmn_pidfile_lock(const char *name) {
int fd;
int pid;
FILE *f;
fd = open(name, O_RDWR | O_CREAT, 0644);
if(fd == -1) {
err_e(errno, "Could not open or create pidfile %s!", name);
return NULL;
}
f = fdopen(fd, "r+");
if(f == NULL) {
err_e(errno, "Could not open pidfile %s!", name);
close(fd);
return NULL;
}
if(flock(fd, LOCK_EX | LOCK_NB)) {
err_e(errno, "Could not lock pidfile %s!", name);
err("Daemon already running?");
fclose(f);
return NULL;
}
pid = getpid();
if(fprintf(f, "%d\n", pid) <= 0) {
err("Could not write to pidfile %s!", name);
fclose(f);
return NULL;
}
if(fflush(f)) {
err_e(errno,"Could not write to pidfile %s!", name);
fclose(f);
return NULL;
}
return f;
}
void dmn_daemonize(void) {
pid_t pid, sid;
pid = fork();
if (pid < 0) {
err_e(errno, "Failed to fork, exiting!");
exit(EXIT_FAILURE);
}
if (pid > 0) {
exit(EXIT_SUCCESS);
}
umask(0);
sid = setsid();
if (sid < 0) {
exit(EXIT_FAILURE);
}
if ((chdir("/")) < 0) {
err_e(errno, "Failed to change directory / , exiting!");
exit(EXIT_FAILURE);
}
/* Redirect standard files to /dev/null */
if(NULL == freopen( "/dev/null", "r", stdin)) {
err_e(errno, "freopen stdin failed, exiting!");
exit(EXIT_FAILURE);
}
if(NULL == freopen( "/dev/null", "w", stdout)) {
err_e(errno, "freopen stdout failed, exiting!");
exit(EXIT_FAILURE);
}
if(NULL == freopen( "/dev/null", "w", stderr)) {
err_e(errno, "freopen stdin failed, exiting!");
exit(EXIT_FAILURE);
}
}
int ossp_slave_process_command(int cmd_fd,
ossp_action_fn_t const *action_fn_tbl,
int (*action_pre_fn)(void),
void (*action_post_fn)(void))
{
static struct sized_buf carg_sbuf = { }, rarg_sbuf = { };
static struct sized_buf din_sbuf = { }, dout_sbuf = { };
struct ossp_cmd cmd;
int fd = -1;
char cmsg_buf[CMSG_SPACE(sizeof(fd))];
struct iovec iov = { &cmd, sizeof(cmd) };
struct msghdr msg = { .msg_iov = &iov, .msg_iovlen = 1,
.msg_control = cmsg_buf,
.msg_controllen = sizeof(cmsg_buf) };
struct cmsghdr *cmsg;
size_t carg_size, din_size, rarg_size, dout_size;
char *carg = NULL, *din = NULL, *rarg = NULL, *dout = NULL;
struct ossp_reply reply = { .magic = OSSP_REPLY_MAGIC };
ssize_t ret;
ret = recvmsg(cmd_fd, &msg, 0);
if (ret == 0)
return 0;
if (ret < 0) {
ret = -errno;
err_e(ret, "failed to read command channel");
return ret;
}
if (ret != sizeof(cmd)) {
err("command struct size mismatch (%zu, should be %zu)",
ret, sizeof(cmd));
return -EINVAL;
}
if (cmd.magic != OSSP_CMD_MAGIC) {
err("illegal command magic 0x%x", cmd.magic);
return -EINVAL;
}
for (cmsg = CMSG_FIRSTHDR(&msg); cmsg;
cmsg = CMSG_NXTHDR(&msg, cmsg)) {
if (cmsg->cmsg_level == SOL_SOCKET &&
cmsg->cmsg_type == SCM_RIGHTS)
fd = *(int *)CMSG_DATA(cmsg);
else {
err("unknown cmsg %d:%d received (opcode %d)",
cmsg->cmsg_level, cmsg->cmsg_type, cmd.opcode);
return -EINVAL;
}
}
if (cmd.opcode >= OSSP_NR_OPCODES) {
err("unknown opcode %d", cmd.opcode);
return -EINVAL;
}
carg_size = ossp_arg_sizes[cmd.opcode].carg_size;
din_size = cmd.din_size;
rarg_size = ossp_arg_sizes[cmd.opcode].rarg_size;
dout_size = cmd.dout_size;
if ((fd >= 0) != ossp_arg_sizes[cmd.opcode].has_fd) {
err("fd=%d unexpected for opcode %d", fd, cmd.opcode);
return -EINVAL;
}
if (ensure_sbuf_size(&carg_sbuf, carg_size) ||
ensure_sbuf_size(&din_sbuf, din_size) ||
ensure_sbuf_size(&rarg_sbuf, rarg_size) ||
ensure_sbuf_size(&dout_sbuf, dout_size)) {
err("failed to allocate command buffers");
return -ENOMEM;
}
if (carg_size) {
carg = carg_sbuf.buf;
ret = read_fill(cmd_fd, carg, carg_size);
if (ret < 0)
return ret;
}
if (din_size) {
din = din_sbuf.buf;
ret = read_fill(cmd_fd, din, din_size);
if (ret < 0)
return ret;
}
if (rarg_size)
rarg = rarg_sbuf.buf;
if (dout_size)
dout = dout_sbuf.buf;
ret = -EINVAL;
if (action_fn_tbl[cmd.opcode]) {
ret = action_pre_fn();
if (ret == 0) {
ret = action_fn_tbl[cmd.opcode](cmd.opcode, carg,
din, din_size, rarg,
dout, &dout_size, fd);
action_post_fn();
}
}
reply.result = ret;
if (ret >= 0)
reply.dout_size = dout_size;
else {
rarg_size = 0;
dout_size = 0;
}
if (write_fill(cmd_fd, &reply, sizeof(reply)) < 0 ||
write_fill(cmd_fd, rarg, rarg_size) < 0 ||
write_fill(cmd_fd, dout, dout_size) < 0)
return -EIO;
return 1;
}
