* Copyright (C) 2007-2009 Daniel Drake <dsd@gentoo.org>
* Copyright (c) 2001 Johannes Erdfelt <johannes@erdfelt.com>
* Copyright (c) 2013 Nathan Hjelm <hjelmn@mac.com>
+ * Copyright (c) 2016 Chris Dickens <christopher.a.dickens@gmail.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
-#include "config.h"
-#include <ctype.h>
-#include <dirent.h>
+#include "libusbi.h"
+#include "linux_usbfs.h"
+
#include <errno.h>
#include <fcntl.h>
#include <poll.h>
-#include <stdio.h>
-#include <stdlib.h>
+#include <pthread.h>
#include <string.h>
-#include <sys/types.h>
+#include <unistd.h>
+
+#ifdef HAVE_ASM_TYPES_H
+#include <asm/types.h>
+#endif
+#include <linux/netlink.h>
#include <sys/socket.h>
-#include <arpa/inet.h>
-#include "libusb.h"
-#include "libusbi.h"
-#include "linux_usbfs.h"
+#define NL_GROUP_KERNEL 1
-#include <linux/netlink.h>
-#include <linux/filter.h>
+#ifndef SOCK_CLOEXEC
+#define SOCK_CLOEXEC 0
+#endif
-#define KERNEL 1
+#ifndef SOCK_NONBLOCK
+#define SOCK_NONBLOCK 0
+#endif
static int linux_netlink_socket = -1;
+static int netlink_control_pipe[2] = { -1, -1 };
static pthread_t libusb_linux_event_thread;
static void *linux_netlink_event_thread_main(void *arg);
-struct sockaddr_nl snl = { .nl_family=AF_NETLINK, .nl_groups=KERNEL };
+static int set_fd_cloexec_nb(int fd, int socktype)
+{
+ int flags;
+
+#if defined(FD_CLOEXEC)
+ /* Make sure the netlink socket file descriptor is marked as CLOEXEC */
+ if (!(socktype & SOCK_CLOEXEC)) {
+ flags = fcntl(fd, F_GETFD);
+ if (flags == -1) {
+ usbi_err(NULL, "failed to get netlink fd flags, errno=%d", errno);
+ return -1;
+ }
+
+ if (fcntl(fd, F_SETFD, flags | FD_CLOEXEC) == -1) {
+ usbi_err(NULL, "failed to set netlink fd flags, errno=%d", errno);
+ return -1;
+ }
+ }
+#endif
+
+ /* Make sure the netlink socket is non-blocking */
+ if (!(socktype & SOCK_NONBLOCK)) {
+ flags = fcntl(fd, F_GETFL);
+ if (flags == -1) {
+ usbi_err(NULL, "failed to get netlink fd status flags, errno=%d", errno);
+ return -1;
+ }
+
+ if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1) {
+ usbi_err(NULL, "failed to set netlink fd status flags, errno=%d", errno);
+ return -1;
+ }
+ }
+
+ return 0;
+}
int linux_netlink_start_event_monitor(void)
{
+ struct sockaddr_nl sa_nl = { .nl_family = AF_NETLINK, .nl_groups = NL_GROUP_KERNEL };
+ int socktype = SOCK_RAW | SOCK_NONBLOCK | SOCK_CLOEXEC;
+ int opt = 1;
int ret;
- snl.nl_groups = KERNEL;
+ linux_netlink_socket = socket(PF_NETLINK, socktype, NETLINK_KOBJECT_UEVENT);
+ if (linux_netlink_socket == -1 && errno == EINVAL) {
+ usbi_dbg("failed to create netlink socket of type %d, attempting SOCK_RAW", socktype);
+ socktype = SOCK_RAW;
+ linux_netlink_socket = socket(PF_NETLINK, socktype, NETLINK_KOBJECT_UEVENT);
+ }
- linux_netlink_socket = socket(PF_NETLINK, SOCK_RAW|SOCK_CLOEXEC|SOCK_NONBLOCK, NETLINK_KOBJECT_UEVENT);
- if (-1 == linux_netlink_socket) {
- return LIBUSB_ERROR_OTHER;
+ if (linux_netlink_socket == -1) {
+ usbi_err(NULL, "failed to create netlink socket, errno=%d", errno);
+ goto err;
}
- ret = bind(linux_netlink_socket, (struct sockaddr *) &snl, sizeof(snl));
- if (0 != ret) {
- return LIBUSB_ERROR_OTHER;
+ ret = set_fd_cloexec_nb(linux_netlink_socket, socktype);
+ if (ret == -1)
+ goto err_close_socket;
+
+ ret = bind(linux_netlink_socket, (struct sockaddr *)&sa_nl, sizeof(sa_nl));
+ if (ret == -1) {
+ usbi_err(NULL, "failed to bind netlink socket, errno=%d", errno);
+ goto err_close_socket;
}
- /* TODO -- add authentication */
- /* setsockopt(linux_netlink_socket, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one)); */
+ ret = setsockopt(linux_netlink_socket, SOL_SOCKET, SO_PASSCRED, &opt, sizeof(opt));
+ if (ret == -1) {
+ usbi_err(NULL, "failed to set netlink socket SO_PASSCRED option, errno=%d", errno);
+ goto err_close_socket;
+ }
+
+ ret = usbi_pipe(netlink_control_pipe);
+ if (ret) {
+ usbi_err(NULL, "failed to create netlink control pipe");
+ goto err_close_socket;
+ }
ret = pthread_create(&libusb_linux_event_thread, NULL, linux_netlink_event_thread_main, NULL);
- if (0 != ret) {
- return LIBUSB_ERROR_OTHER;
+ if (ret != 0) {
+ usbi_err(NULL, "failed to create netlink event thread (%d)", ret);
+ goto err_close_pipe;
}
return LIBUSB_SUCCESS;
+
+err_close_pipe:
+ close(netlink_control_pipe[0]);
+ close(netlink_control_pipe[1]);
+ netlink_control_pipe[0] = -1;
+ netlink_control_pipe[1] = -1;
+err_close_socket:
+ close(linux_netlink_socket);
+ linux_netlink_socket = -1;
+err:
+ return LIBUSB_ERROR_OTHER;
}
int linux_netlink_stop_event_monitor(void)
{
- int r;
+ char dummy = 1;
+ ssize_t r;
- if (-1 == linux_netlink_socket) {
- /* already closed. nothing to do */
- return LIBUSB_SUCCESS;
- }
+ assert(linux_netlink_socket != -1);
- r = close(linux_netlink_socket);
- if (0 > r) {
- usbi_err(NULL, "error closing netlink socket. %s", strerror(errno));
- return LIBUSB_ERROR_OTHER;
- }
+ /* Write some dummy data to the control pipe and
+ * wait for the thread to exit */
+ r = write(netlink_control_pipe[1], &dummy, sizeof(dummy));
+ if (r <= 0)
+ usbi_warn(NULL, "netlink control pipe signal failed");
- pthread_cancel(libusb_linux_event_thread);
+ pthread_join(libusb_linux_event_thread, NULL);
+ close(linux_netlink_socket);
linux_netlink_socket = -1;
+ /* close and reset control pipe */
+ close(netlink_control_pipe[0]);
+ close(netlink_control_pipe[1]);
+ netlink_control_pipe[0] = -1;
+ netlink_control_pipe[1] = -1;
+
return LIBUSB_SUCCESS;
}
-static const char *netlink_message_parse (const char *buffer, size_t len, const char *key)
+static const char *netlink_message_parse(const char *buffer, size_t len, const char *key)
{
+ const char *end = buffer + len;
size_t keylen = strlen(key);
- size_t offset;
- for (offset = 0 ; offset < len && '\0' != buffer[offset] ; offset += strlen(buffer + offset) + 1) {
- if (0 == strncmp(buffer + offset, key, keylen) &&
- '=' == buffer[offset + keylen]) {
- return buffer + offset + keylen + 1;
- }
+ while (buffer < end && *buffer) {
+ if (strncmp(buffer, key, keylen) == 0 && buffer[keylen] == '=')
+ return buffer + keylen + 1;
+ buffer += strlen(buffer) + 1;
}
return NULL;
}
/* parse parts of netlink message common to both libudev and the kernel */
-static int linux_netlink_parse(char *buffer, size_t len, int *detached, const char **sys_name,
- uint8_t *busnum, uint8_t *devaddr) {
- const char *tmp;
- int i;
+static int linux_netlink_parse(const char *buffer, size_t len, int *detached,
+ const char **sys_name, uint8_t *busnum, uint8_t *devaddr)
+{
+ const char *tmp, *slash;
errno = 0;
*busnum = 0;
*devaddr = 0;
- tmp = netlink_message_parse((const char *) buffer, len, "ACTION");
- if (tmp == NULL)
+ tmp = netlink_message_parse(buffer, len, "ACTION");
+ if (!tmp) {
return -1;
- if (0 == strcmp(tmp, "remove")) {
+ } else if (strcmp(tmp, "remove") == 0) {
*detached = 1;
- } else if (0 != strcmp(tmp, "add")) {
+ } else if (strcmp(tmp, "add") != 0) {
usbi_dbg("unknown device action %s", tmp);
return -1;
}
/* check that this is a usb message */
tmp = netlink_message_parse(buffer, len, "SUBSYSTEM");
- if (NULL == tmp || 0 != strcmp(tmp, "usb")) {
+ if (!tmp || strcmp(tmp, "usb") != 0) {
/* not usb. ignore */
return -1;
}
- tmp = netlink_message_parse(buffer, len, "BUSNUM");
- if (NULL == tmp) {
- /* no bus number (likely a usb interface). ignore*/
+ /* check that this is an actual usb device */
+ tmp = netlink_message_parse(buffer, len, "DEVTYPE");
+ if (!tmp || strcmp(tmp, "usb_device") != 0) {
+ /* not usb. ignore */
return -1;
}
- *busnum = (uint8_t)(strtoul(tmp, NULL, 10) & 0xff);
- if (errno) {
- errno = 0;
- return -1;
- }
+ tmp = netlink_message_parse(buffer, len, "BUSNUM");
+ if (tmp) {
+ *busnum = (uint8_t)(strtoul(tmp, NULL, 10) & 0xff);
+ if (errno) {
+ errno = 0;
+ return -1;
+ }
- tmp = netlink_message_parse(buffer, len, "DEVNUM");
- if (NULL == tmp) {
- return -1;
- }
+ tmp = netlink_message_parse(buffer, len, "DEVNUM");
+ if (NULL == tmp)
+ return -1;
- *devaddr = (uint8_t)(strtoul(tmp, NULL, 10) & 0xff);
- if (errno) {
- errno = 0;
- return -1;
+ *devaddr = (uint8_t)(strtoul(tmp, NULL, 10) & 0xff);
+ if (errno) {
+ errno = 0;
+ return -1;
+ }
+ } else {
+ /* no bus number. try "DEVICE" */
+ tmp = netlink_message_parse(buffer, len, "DEVICE");
+ if (!tmp) {
+ /* not usb. ignore */
+ return -1;
+ }
+
+ /* Parse a device path such as /dev/bus/usb/003/004 */
+ slash = strrchr(tmp, '/');
+ if (!slash)
+ return -1;
+
+ *busnum = (uint8_t)(strtoul(slash - 3, NULL, 10) & 0xff);
+ if (errno) {
+ errno = 0;
+ return -1;
+ }
+
+ *devaddr = (uint8_t)(strtoul(slash + 1, NULL, 10) & 0xff);
+ if (errno) {
+ errno = 0;
+ return -1;
+ }
+
+ return 0;
}
tmp = netlink_message_parse(buffer, len, "DEVPATH");
- if (NULL == tmp) {
+ if (!tmp)
return -1;
- }
- for (i = strlen(tmp) - 1 ; i ; --i) {
- if ('/' ==tmp[i]) {
- *sys_name = tmp + i + 1;
- break;
- }
- }
+ slash = strrchr(tmp, '/');
+ if (slash)
+ *sys_name = slash + 1;
/* found a usb device */
return 0;
static int linux_netlink_read_message(void)
{
- unsigned char buffer[1024];
- struct iovec iov = {.iov_base = buffer, .iov_len = sizeof(buffer)};
- struct msghdr meh = { .msg_iov=&iov, .msg_iovlen=1,
- .msg_name=&snl, .msg_namelen=sizeof(snl) };
+ char cred_buffer[CMSG_SPACE(sizeof(struct ucred))];
+ char msg_buffer[2048];
const char *sys_name = NULL;
uint8_t busnum, devaddr;
int detached, r;
- size_t len;
+ ssize_t len;
+ struct cmsghdr *cmsg;
+ struct ucred *cred;
+ struct sockaddr_nl sa_nl;
+ struct iovec iov = { .iov_base = msg_buffer, .iov_len = sizeof(msg_buffer) };
+ struct msghdr msg = {
+ .msg_iov = &iov, .msg_iovlen = 1,
+ .msg_control = cred_buffer, .msg_controllen = sizeof(cred_buffer),
+ .msg_name = &sa_nl, .msg_namelen = sizeof(sa_nl)
+ };
/* read netlink message */
- memset(buffer, 0, sizeof(buffer));
- len = recvmsg(linux_netlink_socket, &meh, 0);
- if (len < 32) {
- if (errno != EAGAIN)
- usbi_dbg("error recieving message from netlink");
+ len = recvmsg(linux_netlink_socket, &msg, 0);
+ if (len == -1) {
+ if (errno != EAGAIN && errno != EINTR)
+ usbi_err(NULL, "error receiving message from netlink, errno=%d", errno);
return -1;
}
- /* TODO -- authenticate this message is from the kernel or udevd */
+ if (len < 32 || (msg.msg_flags & MSG_TRUNC)) {
+ usbi_err(NULL, "invalid netlink message length");
+ return -1;
+ }
+
+ if (sa_nl.nl_groups != NL_GROUP_KERNEL || sa_nl.nl_pid != 0) {
+ usbi_dbg("ignoring netlink message from unknown group/PID (%u/%u)",
+ (unsigned int)sa_nl.nl_groups, (unsigned int)sa_nl.nl_pid);
+ return -1;
+ }
+
+ cmsg = CMSG_FIRSTHDR(&msg);
+ if (!cmsg || cmsg->cmsg_type != SCM_CREDENTIALS) {
+ usbi_dbg("ignoring netlink message with no sender credentials");
+ return -1;
+ }
+
+ cred = (struct ucred *)CMSG_DATA(cmsg);
+ if (cred->uid != 0) {
+ usbi_dbg("ignoring netlink message with non-zero sender UID %u", (unsigned int)cred->uid);
+ return -1;
+ }
- r = linux_netlink_parse(buffer, len, &detached, &sys_name,
- &busnum, &devaddr);
+ r = linux_netlink_parse(msg_buffer, (size_t)len, &detached, &sys_name, &busnum, &devaddr);
if (r)
return r;
/* signal device is available (or not) to all contexts */
if (detached)
- linux_hotplug_disconnected(busnum, devaddr, sys_name);
+ linux_device_disconnected(busnum, devaddr);
else
linux_hotplug_enumerate(busnum, devaddr, sys_name);
static void *linux_netlink_event_thread_main(void *arg)
{
- struct pollfd fds = {.fd = linux_netlink_socket,
- .events = POLLIN};
-
- /* silence compiler warning */
- (void) arg;
-
- while (1 == poll(&fds, 1, -1)) {
- if (POLLIN != fds.revents) {
+ char dummy;
+ int r;
+ ssize_t nb;
+ struct pollfd fds[] = {
+ { .fd = netlink_control_pipe[0],
+ .events = POLLIN },
+ { .fd = linux_netlink_socket,
+ .events = POLLIN },
+ };
+
+ UNUSED(arg);
+
+ usbi_dbg("netlink event thread entering");
+
+ while ((r = poll(fds, 2, -1)) >= 0 || errno == EINTR) {
+ if (r < 0) {
+ /* temporary failure */
+ continue;
+ }
+ if (fds[0].revents & POLLIN) {
+ /* activity on control pipe, read the byte and exit */
+ nb = read(netlink_control_pipe[0], &dummy, sizeof(dummy));
+ if (nb <= 0)
+ usbi_warn(NULL, "netlink control pipe read failed");
break;
}
-
- usbi_mutex_static_lock(&linux_hotplug_lock);
- linux_netlink_read_message();
- usbi_mutex_static_unlock(&linux_hotplug_lock);
+ if (fds[1].revents & POLLIN) {
+ usbi_mutex_static_lock(&linux_hotplug_lock);
+ linux_netlink_read_message();
+ usbi_mutex_static_unlock(&linux_hotplug_lock);
+ }
}
+ usbi_dbg("netlink event thread exiting");
+
return NULL;
}
projects / platform / upstream / libusb.git / blobdiff