blob: e4348c314d4b2632cf2e755072daee547aae608e [file] [log] [blame]
/*
* libudev - interface to udev device information
*
* Copyright (C) 2008 Kay Sievers <kay.sievers@vrfy.org>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*/
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/poll.h>
#include <sys/socket.h>
#include <sys/un.h>
#include "udev.h"
/* wire protocol magic must match */
#define UDEV_CTRL_MAGIC 0xdead1dea
enum udev_ctrl_msg_type {
UDEV_CTRL_UNKNOWN,
UDEV_CTRL_SET_LOG_LEVEL,
UDEV_CTRL_STOP_EXEC_QUEUE,
UDEV_CTRL_START_EXEC_QUEUE,
UDEV_CTRL_RELOAD_RULES,
UDEV_CTRL_SET_ENV,
UDEV_CTRL_SET_CHILDREN_MAX,
UDEV_CTRL_PING,
UDEV_CTRL_EXIT,
};
struct udev_ctrl_msg_wire {
char version[16];
unsigned int magic;
enum udev_ctrl_msg_type type;
union {
int intval;
char buf[256];
};
};
struct udev_ctrl_msg {
int refcount;
struct udev_ctrl_connection *conn;
struct udev_ctrl_msg_wire ctrl_msg_wire;
};
struct udev_ctrl {
int refcount;
struct udev *udev;
int sock;
struct sockaddr_un saddr;
socklen_t addrlen;
bool bound;
bool cleanup_socket;
bool connected;
};
struct udev_ctrl_connection {
int refcount;
struct udev_ctrl *uctrl;
int sock;
};
struct udev_ctrl *udev_ctrl_new_from_fd(struct udev *udev, int fd)
{
struct udev_ctrl *uctrl;
uctrl = calloc(1, sizeof(struct udev_ctrl));
if (uctrl == NULL)
return NULL;
uctrl->refcount = 1;
uctrl->udev = udev;
if (fd < 0) {
uctrl->sock = socket(AF_LOCAL, SOCK_SEQPACKET|SOCK_NONBLOCK|SOCK_CLOEXEC, 0);
if (uctrl->sock < 0) {
err(udev, "error getting socket: %m\n");
udev_ctrl_unref(uctrl);
return NULL;
}
} else {
uctrl->bound = true;
uctrl->sock = fd;
}
uctrl->saddr.sun_family = AF_LOCAL;
util_strscpyl(uctrl->saddr.sun_path, sizeof(uctrl->saddr.sun_path),
udev_get_run_path(udev), "/control", NULL);
uctrl->addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(uctrl->saddr.sun_path);
return uctrl;
}
struct udev_ctrl *udev_ctrl_new(struct udev *udev)
{
return udev_ctrl_new_from_fd(udev, -1);
}
int udev_ctrl_enable_receiving(struct udev_ctrl *uctrl)
{
int err;
if (!uctrl->bound) {
err = bind(uctrl->sock, (struct sockaddr *)&uctrl->saddr, uctrl->addrlen);
if (err < 0 && errno == EADDRINUSE) {
unlink(uctrl->saddr.sun_path);
err = bind(uctrl->sock, (struct sockaddr *)&uctrl->saddr, uctrl->addrlen);
}
if (err < 0) {
err = -errno;
err(uctrl->udev, "bind failed: %m\n");
return err;
}
err = listen(uctrl->sock, 0);
if (err < 0) {
err = -errno;
err(uctrl->udev, "listen failed: %m\n");
return err;
}
uctrl->bound = true;
uctrl->cleanup_socket = true;
}
return 0;
}
struct udev *udev_ctrl_get_udev(struct udev_ctrl *uctrl)
{
return uctrl->udev;
}
struct udev_ctrl *udev_ctrl_ref(struct udev_ctrl *uctrl)
{
if (uctrl == NULL)
return NULL;
uctrl->refcount++;
return uctrl;
}
struct udev_ctrl *udev_ctrl_unref(struct udev_ctrl *uctrl)
{
if (uctrl == NULL)
return NULL;
uctrl->refcount--;
if (uctrl->refcount > 0)
return uctrl;
if (uctrl->sock >= 0)
close(uctrl->sock);
free(uctrl);
return NULL;
}
int udev_ctrl_cleanup(struct udev_ctrl *uctrl)
{
if (uctrl == NULL)
return 0;
if (uctrl->cleanup_socket)
unlink(uctrl->saddr.sun_path);
return 0;
}
int udev_ctrl_get_fd(struct udev_ctrl *uctrl)
{
if (uctrl == NULL)
return -EINVAL;
return uctrl->sock;
}
struct udev_ctrl_connection *udev_ctrl_get_connection(struct udev_ctrl *uctrl)
{
struct udev_ctrl_connection *conn;
struct ucred ucred;
socklen_t slen;
const int on = 1;
conn = calloc(1, sizeof(struct udev_ctrl_connection));
if (conn == NULL)
return NULL;
conn->refcount = 1;
conn->uctrl = uctrl;
conn->sock = accept4(uctrl->sock, NULL, NULL, SOCK_CLOEXEC|SOCK_NONBLOCK);
if (conn->sock < 0) {
if (errno != EINTR)
err(uctrl->udev, "unable to receive ctrl connection: %m\n");
goto err;
}
/* check peer credential of connection */
slen = sizeof(ucred);
if (getsockopt(conn->sock, SOL_SOCKET, SO_PEERCRED, &ucred, &slen) < 0) {
err(uctrl->udev, "unable to receive credentials of ctrl connection: %m\n");
goto err;
}
if (ucred.uid > 0) {
err(uctrl->udev, "sender uid=%i, message ignored\n", ucred.uid);
goto err;
}
/* enable receiving of the sender credentials in the messages */
setsockopt(conn->sock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on));
udev_ctrl_ref(uctrl);
return conn;
err:
if (conn->sock >= 0)
close(conn->sock);
free(conn);
return NULL;
}
struct udev_ctrl_connection *udev_ctrl_connection_ref(struct udev_ctrl_connection *conn)
{
if (conn == NULL)
return NULL;
conn->refcount++;
return conn;
}
struct udev_ctrl_connection *udev_ctrl_connection_unref(struct udev_ctrl_connection *conn)
{
if (conn == NULL)
return NULL;
conn->refcount--;
if (conn->refcount > 0)
return conn;
if (conn->sock >= 0)
close(conn->sock);
udev_ctrl_unref(conn->uctrl);
free(conn);
return NULL;
}
static int ctrl_send(struct udev_ctrl *uctrl, enum udev_ctrl_msg_type type, int intval, const char *buf, int timeout)
{
struct udev_ctrl_msg_wire ctrl_msg_wire;
int err = 0;
memset(&ctrl_msg_wire, 0x00, sizeof(struct udev_ctrl_msg_wire));
strcpy(ctrl_msg_wire.version, "udev-" VERSION);
ctrl_msg_wire.magic = UDEV_CTRL_MAGIC;
ctrl_msg_wire.type = type;
if (buf != NULL)
util_strscpy(ctrl_msg_wire.buf, sizeof(ctrl_msg_wire.buf), buf);
else
ctrl_msg_wire.intval = intval;
if (!uctrl->connected) {
if (connect(uctrl->sock, (struct sockaddr *)&uctrl->saddr, uctrl->addrlen) < 0) {
err = -errno;
goto out;
}
uctrl->connected = true;
}
if (send(uctrl->sock, &ctrl_msg_wire, sizeof(ctrl_msg_wire), 0) < 0) {
err = -errno;
goto out;
}
/* wait for peer message handling or disconnect */
for (;;) {
struct pollfd pfd[1];
int r;
pfd[0].fd = uctrl->sock;
pfd[0].events = POLLIN;
r = poll(pfd, 1, timeout * 1000);
if (r < 0) {
if (errno == EINTR)
continue;
err = -errno;
break;
}
if (r > 0 && pfd[0].revents & POLLERR) {
err = -EIO;
break;
}
if (r == 0)
err = -ETIMEDOUT;
break;
}
out:
return err;
}
int udev_ctrl_send_set_log_level(struct udev_ctrl *uctrl, int priority, int timeout)
{
return ctrl_send(uctrl, UDEV_CTRL_SET_LOG_LEVEL, priority, NULL, timeout);
}
int udev_ctrl_send_stop_exec_queue(struct udev_ctrl *uctrl, int timeout)
{
return ctrl_send(uctrl, UDEV_CTRL_STOP_EXEC_QUEUE, 0, NULL, timeout);
}
int udev_ctrl_send_start_exec_queue(struct udev_ctrl *uctrl, int timeout)
{
return ctrl_send(uctrl, UDEV_CTRL_START_EXEC_QUEUE, 0, NULL, timeout);
}
int udev_ctrl_send_reload_rules(struct udev_ctrl *uctrl, int timeout)
{
return ctrl_send(uctrl, UDEV_CTRL_RELOAD_RULES, 0, NULL, timeout);
}
int udev_ctrl_send_set_env(struct udev_ctrl *uctrl, const char *key, int timeout)
{
return ctrl_send(uctrl, UDEV_CTRL_SET_ENV, 0, key, timeout);
}
int udev_ctrl_send_set_children_max(struct udev_ctrl *uctrl, int count, int timeout)
{
return ctrl_send(uctrl, UDEV_CTRL_SET_CHILDREN_MAX, count, NULL, timeout);
}
int udev_ctrl_send_ping(struct udev_ctrl *uctrl, int timeout)
{
return ctrl_send(uctrl, UDEV_CTRL_PING, 0, NULL, timeout);
}
int udev_ctrl_send_exit(struct udev_ctrl *uctrl, int timeout)
{
return ctrl_send(uctrl, UDEV_CTRL_EXIT, 0, NULL, timeout);
}
struct udev_ctrl_msg *udev_ctrl_receive_msg(struct udev_ctrl_connection *conn)
{
struct udev *udev = conn->uctrl->udev;
struct udev_ctrl_msg *uctrl_msg;
ssize_t size;
struct msghdr smsg;
struct cmsghdr *cmsg;
struct iovec iov;
struct ucred *cred;
char cred_msg[CMSG_SPACE(sizeof(struct ucred))];
uctrl_msg = calloc(1, sizeof(struct udev_ctrl_msg));
if (uctrl_msg == NULL)
return NULL;
uctrl_msg->refcount = 1;
uctrl_msg->conn = conn;
udev_ctrl_connection_ref(conn);
/* wait for the incoming message */
for(;;) {
struct pollfd pfd[1];
int r;
pfd[0].fd = conn->sock;
pfd[0].events = POLLIN;
r = poll(pfd, 1, 10000);
if (r < 0) {
if (errno == EINTR)
continue;
goto err;
} else if (r == 0) {
err(udev, "timeout waiting for ctrl message\n");
goto err;
} else {
if (!(pfd[0].revents & POLLIN)) {
err(udev, "ctrl connection error: %m\n");
goto err;
}
}
break;
}
iov.iov_base = &uctrl_msg->ctrl_msg_wire;
iov.iov_len = sizeof(struct udev_ctrl_msg_wire);
memset(&smsg, 0x00, sizeof(struct msghdr));
smsg.msg_iov = &iov;
smsg.msg_iovlen = 1;
smsg.msg_control = cred_msg;
smsg.msg_controllen = sizeof(cred_msg);
size = recvmsg(conn->sock, &smsg, 0);
if (size < 0) {
err(udev, "unable to receive ctrl message: %m\n");
goto err;
}
cmsg = CMSG_FIRSTHDR(&smsg);
cred = (struct ucred *) CMSG_DATA(cmsg);
if (cmsg == NULL || cmsg->cmsg_type != SCM_CREDENTIALS) {
err(udev, "no sender credentials received, message ignored\n");
goto err;
}
if (cred->uid != 0) {
err(udev, "sender uid=%i, message ignored\n", cred->uid);
goto err;
}
if (uctrl_msg->ctrl_msg_wire.magic != UDEV_CTRL_MAGIC) {
err(udev, "message magic 0x%08x doesn't match, ignore it\n", uctrl_msg->ctrl_msg_wire.magic);
goto err;
}
dbg(udev, "created ctrl_msg %p (%i)\n", uctrl_msg, uctrl_msg->ctrl_msg_wire.type);
return uctrl_msg;
err:
udev_ctrl_msg_unref(uctrl_msg);
return NULL;
}
struct udev_ctrl_msg *udev_ctrl_msg_ref(struct udev_ctrl_msg *ctrl_msg)
{
if (ctrl_msg == NULL)
return NULL;
ctrl_msg->refcount++;
return ctrl_msg;
}
struct udev_ctrl_msg *udev_ctrl_msg_unref(struct udev_ctrl_msg *ctrl_msg)
{
if (ctrl_msg == NULL)
return NULL;
ctrl_msg->refcount--;
if (ctrl_msg->refcount > 0)
return ctrl_msg;
dbg(ctrl_msg->conn->uctrl->udev, "release ctrl_msg %p\n", ctrl_msg);
udev_ctrl_connection_unref(ctrl_msg->conn);
free(ctrl_msg);
return NULL;
}
int udev_ctrl_get_set_log_level(struct udev_ctrl_msg *ctrl_msg)
{
if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_SET_LOG_LEVEL)
return ctrl_msg->ctrl_msg_wire.intval;
return -1;
}
int udev_ctrl_get_stop_exec_queue(struct udev_ctrl_msg *ctrl_msg)
{
if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_STOP_EXEC_QUEUE)
return 1;
return -1;
}
int udev_ctrl_get_start_exec_queue(struct udev_ctrl_msg *ctrl_msg)
{
if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_START_EXEC_QUEUE)
return 1;
return -1;
}
int udev_ctrl_get_reload_rules(struct udev_ctrl_msg *ctrl_msg)
{
if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_RELOAD_RULES)
return 1;
return -1;
}
const char *udev_ctrl_get_set_env(struct udev_ctrl_msg *ctrl_msg)
{
if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_SET_ENV)
return ctrl_msg->ctrl_msg_wire.buf;
return NULL;
}
int udev_ctrl_get_set_children_max(struct udev_ctrl_msg *ctrl_msg)
{
if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_SET_CHILDREN_MAX)
return ctrl_msg->ctrl_msg_wire.intval;
return -1;
}
int udev_ctrl_get_ping(struct udev_ctrl_msg *ctrl_msg)
{
if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_PING)
return 1;
return -1;
}
int udev_ctrl_get_exit(struct udev_ctrl_msg *ctrl_msg)
{
if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_EXIT)
return 1;
return -1;
}