| /* |
| * WPA Supplicant - Layer2 packet handling with privilege separation |
| * Copyright (c) 2007, Jouni Malinen <j@w1.fi> |
| * |
| * This software may be distributed under the terms of the BSD license. |
| * See README for more details. |
| */ |
| |
| #include "includes.h" |
| #include <sys/un.h> |
| |
| #include "common.h" |
| #include "eloop.h" |
| #include "l2_packet.h" |
| #include "common/privsep_commands.h" |
| |
| |
| struct l2_packet_data { |
| int fd; /* UNIX domain socket for privsep access */ |
| void (*rx_callback)(void *ctx, const u8 *src_addr, |
| const u8 *buf, size_t len); |
| void *rx_callback_ctx; |
| u8 own_addr[ETH_ALEN]; |
| char *own_socket_path; |
| struct sockaddr_un priv_addr; |
| }; |
| |
| |
| static int wpa_priv_cmd(struct l2_packet_data *l2, int cmd, |
| const void *data, size_t data_len) |
| { |
| struct msghdr msg; |
| struct iovec io[2]; |
| |
| io[0].iov_base = &cmd; |
| io[0].iov_len = sizeof(cmd); |
| io[1].iov_base = (u8 *) data; |
| io[1].iov_len = data_len; |
| |
| os_memset(&msg, 0, sizeof(msg)); |
| msg.msg_iov = io; |
| msg.msg_iovlen = data ? 2 : 1; |
| msg.msg_name = &l2->priv_addr; |
| msg.msg_namelen = sizeof(l2->priv_addr); |
| |
| if (sendmsg(l2->fd, &msg, 0) < 0) { |
| perror("L2: sendmsg(cmd)"); |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| |
| int l2_packet_get_own_addr(struct l2_packet_data *l2, u8 *addr) |
| { |
| os_memcpy(addr, l2->own_addr, ETH_ALEN); |
| return 0; |
| } |
| |
| |
| int l2_packet_send(struct l2_packet_data *l2, const u8 *dst_addr, u16 proto, |
| const u8 *buf, size_t len) |
| { |
| struct msghdr msg; |
| struct iovec io[4]; |
| int cmd = PRIVSEP_CMD_L2_SEND; |
| |
| io[0].iov_base = &cmd; |
| io[0].iov_len = sizeof(cmd); |
| io[1].iov_base = &dst_addr; |
| io[1].iov_len = ETH_ALEN; |
| io[2].iov_base = &proto; |
| io[2].iov_len = 2; |
| io[3].iov_base = (u8 *) buf; |
| io[3].iov_len = len; |
| |
| os_memset(&msg, 0, sizeof(msg)); |
| msg.msg_iov = io; |
| msg.msg_iovlen = 4; |
| msg.msg_name = &l2->priv_addr; |
| msg.msg_namelen = sizeof(l2->priv_addr); |
| |
| if (sendmsg(l2->fd, &msg, 0) < 0) { |
| perror("L2: sendmsg(packet_send)"); |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| |
| static void l2_packet_receive(int sock, void *eloop_ctx, void *sock_ctx) |
| { |
| struct l2_packet_data *l2 = eloop_ctx; |
| u8 buf[2300]; |
| int res; |
| struct sockaddr_un from; |
| socklen_t fromlen = sizeof(from); |
| |
| os_memset(&from, 0, sizeof(from)); |
| res = recvfrom(sock, buf, sizeof(buf), 0, (struct sockaddr *) &from, |
| &fromlen); |
| if (res < 0) { |
| perror("l2_packet_receive - recvfrom"); |
| return; |
| } |
| if (res < ETH_ALEN) { |
| wpa_printf(MSG_DEBUG, "L2: Too show packet received"); |
| return; |
| } |
| |
| if (from.sun_family != AF_UNIX || |
| os_strncmp(from.sun_path, l2->priv_addr.sun_path, |
| sizeof(from.sun_path)) != 0) { |
| wpa_printf(MSG_DEBUG, "L2: Received message from unexpected " |
| "source"); |
| return; |
| } |
| |
| l2->rx_callback(l2->rx_callback_ctx, buf, buf + ETH_ALEN, |
| res - ETH_ALEN); |
| } |
| |
| |
| struct l2_packet_data * l2_packet_init( |
| const char *ifname, const u8 *own_addr, unsigned short protocol, |
| void (*rx_callback)(void *ctx, const u8 *src_addr, |
| const u8 *buf, size_t len), |
| void *rx_callback_ctx, int l2_hdr) |
| { |
| struct l2_packet_data *l2; |
| char *own_dir = "/tmp"; |
| char *priv_dir = "/var/run/wpa_priv"; |
| size_t len; |
| static unsigned int counter = 0; |
| struct sockaddr_un addr; |
| fd_set rfds; |
| struct timeval tv; |
| int res; |
| u8 reply[ETH_ALEN + 1]; |
| int reg_cmd[2]; |
| |
| l2 = os_zalloc(sizeof(struct l2_packet_data)); |
| if (l2 == NULL) |
| return NULL; |
| l2->rx_callback = rx_callback; |
| l2->rx_callback_ctx = rx_callback_ctx; |
| |
| len = os_strlen(own_dir) + 50; |
| l2->own_socket_path = os_malloc(len); |
| if (l2->own_socket_path == NULL) { |
| os_free(l2); |
| return NULL; |
| } |
| os_snprintf(l2->own_socket_path, len, "%s/wpa_privsep-l2-%d-%d", |
| own_dir, getpid(), counter++); |
| |
| l2->priv_addr.sun_family = AF_UNIX; |
| os_snprintf(l2->priv_addr.sun_path, sizeof(l2->priv_addr.sun_path), |
| "%s/%s", priv_dir, ifname); |
| |
| l2->fd = socket(PF_UNIX, SOCK_DGRAM, 0); |
| if (l2->fd < 0) { |
| perror("socket(PF_UNIX)"); |
| os_free(l2->own_socket_path); |
| l2->own_socket_path = NULL; |
| os_free(l2); |
| return NULL; |
| } |
| |
| os_memset(&addr, 0, sizeof(addr)); |
| addr.sun_family = AF_UNIX; |
| os_strlcpy(addr.sun_path, l2->own_socket_path, sizeof(addr.sun_path)); |
| if (bind(l2->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) { |
| perror("l2-pkt-privsep: bind(PF_UNIX)"); |
| goto fail; |
| } |
| |
| reg_cmd[0] = protocol; |
| reg_cmd[1] = l2_hdr; |
| if (wpa_priv_cmd(l2, PRIVSEP_CMD_L2_REGISTER, reg_cmd, sizeof(reg_cmd)) |
| < 0) { |
| wpa_printf(MSG_ERROR, "L2: Failed to register with wpa_priv"); |
| goto fail; |
| } |
| |
| FD_ZERO(&rfds); |
| FD_SET(l2->fd, &rfds); |
| tv.tv_sec = 5; |
| tv.tv_usec = 0; |
| res = select(l2->fd + 1, &rfds, NULL, NULL, &tv); |
| if (res < 0 && errno != EINTR) { |
| perror("select"); |
| goto fail; |
| } |
| |
| if (FD_ISSET(l2->fd, &rfds)) { |
| res = recv(l2->fd, reply, sizeof(reply), 0); |
| if (res < 0) { |
| perror("recv"); |
| goto fail; |
| } |
| } else { |
| wpa_printf(MSG_DEBUG, "L2: Timeout while waiting for " |
| "registration reply"); |
| goto fail; |
| } |
| |
| if (res != ETH_ALEN) { |
| wpa_printf(MSG_DEBUG, "L2: Unexpected registration reply " |
| "(len=%d)", res); |
| } |
| os_memcpy(l2->own_addr, reply, ETH_ALEN); |
| |
| eloop_register_read_sock(l2->fd, l2_packet_receive, l2, NULL); |
| |
| return l2; |
| |
| fail: |
| close(l2->fd); |
| l2->fd = -1; |
| unlink(l2->own_socket_path); |
| os_free(l2->own_socket_path); |
| l2->own_socket_path = NULL; |
| os_free(l2); |
| return NULL; |
| } |
| |
| |
| void l2_packet_deinit(struct l2_packet_data *l2) |
| { |
| if (l2 == NULL) |
| return; |
| |
| if (l2->fd >= 0) { |
| wpa_priv_cmd(l2, PRIVSEP_CMD_L2_UNREGISTER, NULL, 0); |
| eloop_unregister_read_sock(l2->fd); |
| close(l2->fd); |
| } |
| |
| if (l2->own_socket_path) { |
| unlink(l2->own_socket_path); |
| os_free(l2->own_socket_path); |
| } |
| |
| os_free(l2); |
| } |
| |
| |
| int l2_packet_get_ip_addr(struct l2_packet_data *l2, char *buf, size_t len) |
| { |
| /* TODO */ |
| return -1; |
| } |
| |
| |
| void l2_packet_notify_auth_start(struct l2_packet_data *l2) |
| { |
| wpa_priv_cmd(l2, PRIVSEP_CMD_L2_NOTIFY_AUTH_START, NULL, 0); |
| } |