driver_wired.c

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/*
 * Wired Ethernet driver interface
 * Copyright (c) 2005-2009, Jouni Malinen <j@w1.fi>
 * Copyright (c) 2004, Gunter Burchardt <tira@isx.de>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Alternatively, this software may be distributed under the terms of BSD
 * license.
 *
 * See README and COPYING for more details.
 */

#include "includes.h"
#include <sys/ioctl.h>
#include <net/if.h>
#ifdef __linux__
#include <netpacket/packet.h>
#include <net/if_arp.h>
#include <net/if.h>
#endif /* __linux__ */
#if defined(__FreeBSD__) || defined(__DragonFly__) || defined(__FreeBSD_kernel__)
#include <net/if_dl.h>
#endif /* defined(__FreeBSD__) || defined(__DragonFly__) || defined(__FreeBSD_kernel__) */

#include "common.h"
#include "eloop.h"
#include "driver.h"

#ifdef _MSC_VER
#pragma pack(push, 1)
#endif /* _MSC_VER */

struct ieee8023_hdr {
        u8 dest[6];
        u8 src[6];
        u16 ethertype;
} STRUCT_PACKED;

#ifdef _MSC_VER
#pragma pack(pop)
#endif /* _MSC_VER */

static const u8 pae_group_addr[ETH_ALEN] =
{ 0x01, 0x80, 0xc2, 0x00, 0x00, 0x03 };


struct wpa_driver_wired_data {
        char ifname[IFNAMSIZ + 1];
        void *ctx;

        int sock; /* raw packet socket for driver access */
        int dhcp_sock; /* socket for dhcp packets */
        int use_pae_group_addr;

        int pf_sock;
        int membership, multi, iff_allmulti, iff_up;
};


/* TODO: detecting new devices should eventually be changed from using DHCP
 * snooping to trigger on any packet from a new layer 2 MAC address, e.g.,
 * based on ebtables, etc. */

struct dhcp_message {
        u_int8_t op;
        u_int8_t htype;
        u_int8_t hlen;
        u_int8_t hops;
        u_int32_t xid;
        u_int16_t secs;
        u_int16_t flags;
        u_int32_t ciaddr;
        u_int32_t yiaddr;
        u_int32_t siaddr;
        u_int32_t giaddr;
        u_int8_t chaddr[16];
        u_int8_t sname[64];
        u_int8_t file[128];
        u_int32_t cookie;
        u_int8_t options[308]; /* 312 - cookie */
};


static int wired_multicast_membership(int sock, int ifindex,
                                      const u8 *addr, int add)
{
#ifdef __linux__
        struct packet_mreq mreq;

        if (sock < 0)
                return -1;

        os_memset(&mreq, 0, sizeof(mreq));
        mreq.mr_ifindex = ifindex;
        mreq.mr_type = PACKET_MR_MULTICAST;
        mreq.mr_alen = ETH_ALEN;
        os_memcpy(mreq.mr_address, addr, ETH_ALEN);

        if (setsockopt(sock, SOL_PACKET,
                       add ? PACKET_ADD_MEMBERSHIP : PACKET_DROP_MEMBERSHIP,
                       &mreq, sizeof(mreq)) < 0) {
                perror("setsockopt");
                return -1;
        }
        return 0;
#else /* __linux__ */
        return -1;
#endif /* __linux__ */
}


#ifdef __linux__
static void handle_data(void *ctx, unsigned char *buf, size_t len)
{
#ifdef HOSTAPD
        struct ieee8023_hdr *hdr;
        u8 *pos, *sa;
        size_t left;
        union wpa_event_data event;

        /* must contain at least ieee8023_hdr 6 byte source, 6 byte dest,
         * 2 byte ethertype */
        if (len < 14) {
                wpa_printf(MSG_MSGDUMP, "handle_data: too short (%lu)",
                           (unsigned long) len);
                return;
        }

        hdr = (struct ieee8023_hdr *) buf;

        switch (ntohs(hdr->ethertype)) {
                case ETH_P_PAE:
                        wpa_printf(MSG_MSGDUMP, "Received EAPOL packet");
                        sa = hdr->src;
                        os_memset(&event, 0, sizeof(event));
                        event.new_sta.addr = sa;
                        wpa_supplicant_event(ctx, EVENT_NEW_STA, &event);

                        pos = (u8 *) (hdr + 1);
                        left = len - sizeof(*hdr);
                        drv_event_eapol_rx(ctx, sa, pos, left);
                break;

        default:
                wpa_printf(MSG_DEBUG, "Unknown ethertype 0x%04x in data frame",
                           ntohs(hdr->ethertype));
                break;
        }
#endif /* HOSTAPD */
}


static void handle_read(int sock, void *eloop_ctx, void *sock_ctx)
{
        int len;
        unsigned char buf[3000];

        len = recv(sock, buf, sizeof(buf), 0);
        if (len < 0) {
                perror("recv");
                return;
        }

        handle_data(eloop_ctx, buf, len);
}


static void handle_dhcp(int sock, void *eloop_ctx, void *sock_ctx)
{
        int len;
        unsigned char buf[3000];
        struct dhcp_message *msg;
        u8 *mac_address;
        union wpa_event_data event;

        len = recv(sock, buf, sizeof(buf), 0);
        if (len < 0) {
                perror("recv");
                return;
        }

        /* must contain at least dhcp_message->chaddr */
        if (len < 44) {
                wpa_printf(MSG_MSGDUMP, "handle_dhcp: too short (%d)", len);
                return;
        }

        msg = (struct dhcp_message *) buf;
        mac_address = (u8 *) &(msg->chaddr);

        wpa_printf(MSG_MSGDUMP, "Got DHCP broadcast packet from " MACSTR,
                   MAC2STR(mac_address));

        os_memset(&event, 0, sizeof(event));
        event.new_sta.addr = mac_address;
        wpa_supplicant_event(eloop_ctx, EVENT_NEW_STA, &event);
}
#endif /* __linux__ */


static int wired_init_sockets(struct wpa_driver_wired_data *drv, u8 *own_addr)
{
#ifdef __linux__
        struct ifreq ifr;
        struct sockaddr_ll addr;
        struct sockaddr_in addr2;
        int n = 1;

        drv->sock = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_PAE));
        if (drv->sock < 0) {
                perror("socket[PF_PACKET,SOCK_RAW]");
                return -1;
        }

        if (eloop_register_read_sock(drv->sock, handle_read, drv->ctx, NULL)) {
                printf("Could not register read socket\n");
                return -1;
        }

        os_memset(&ifr, 0, sizeof(ifr));
        os_strlcpy(ifr.ifr_name, drv->ifname, sizeof(ifr.ifr_name));
        if (ioctl(drv->sock, SIOCGIFINDEX, &ifr) != 0) {
                perror("ioctl(SIOCGIFINDEX)");
                return -1;
        }

        os_memset(&addr, 0, sizeof(addr));
        addr.sll_family = AF_PACKET;
        addr.sll_ifindex = ifr.ifr_ifindex;
        wpa_printf(MSG_DEBUG, "Opening raw packet socket for ifindex %d",
                   addr.sll_ifindex);

        if (bind(drv->sock, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
                perror("bind");
                return -1;
        }

        /* filter multicast address */
        if (wired_multicast_membership(drv->sock, ifr.ifr_ifindex,
                                       pae_group_addr, 1) < 0) {
                wpa_printf(MSG_ERROR, "wired: Failed to add multicast group "
                           "membership");
                return -1;
        }

        os_memset(&ifr, 0, sizeof(ifr));
        os_strlcpy(ifr.ifr_name, drv->ifname, sizeof(ifr.ifr_name));
        if (ioctl(drv->sock, SIOCGIFHWADDR, &ifr) != 0) {
                perror("ioctl(SIOCGIFHWADDR)");
                return -1;
        }

        if (ifr.ifr_hwaddr.sa_family != ARPHRD_ETHER) {
                printf("Invalid HW-addr family 0x%04x\n",
                       ifr.ifr_hwaddr.sa_family);
                return -1;
        }
        os_memcpy(own_addr, ifr.ifr_hwaddr.sa_data, ETH_ALEN);

        /* setup dhcp listen socket for sta detection */
        if ((drv->dhcp_sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
                perror("socket call failed for dhcp");
                return -1;
        }

        if (eloop_register_read_sock(drv->dhcp_sock, handle_dhcp, drv->ctx,
                                     NULL)) {
                printf("Could not register read socket\n");
                return -1;
        }

        os_memset(&addr2, 0, sizeof(addr2));
        addr2.sin_family = AF_INET;
        addr2.sin_port = htons(67);
        addr2.sin_addr.s_addr = INADDR_ANY;

        if (setsockopt(drv->dhcp_sock, SOL_SOCKET, SO_REUSEADDR, (char *) &n,
                       sizeof(n)) == -1) {
                perror("setsockopt[SOL_SOCKET,SO_REUSEADDR]");
                return -1;
        }
        if (setsockopt(drv->dhcp_sock, SOL_SOCKET, SO_BROADCAST, (char *) &n,
                       sizeof(n)) == -1) {
                perror("setsockopt[SOL_SOCKET,SO_BROADCAST]");
                return -1;
        }

        os_memset(&ifr, 0, sizeof(ifr));
        os_strlcpy(ifr.ifr_ifrn.ifrn_name, drv->ifname, IFNAMSIZ);
        if (setsockopt(drv->dhcp_sock, SOL_SOCKET, SO_BINDTODEVICE,
                       (char *) &ifr, sizeof(ifr)) < 0) {
                perror("setsockopt[SOL_SOCKET,SO_BINDTODEVICE]");
                return -1;
        }

        if (bind(drv->dhcp_sock, (struct sockaddr *) &addr2,
                 sizeof(struct sockaddr)) == -1) {
                perror("bind");
                return -1;
        }

        return 0;
#else /* __linux__ */
        return -1;
#endif /* __linux__ */
}


static int wired_send_eapol(void *priv, const u8 *addr,
                            const u8 *data, size_t data_len, int encrypt,
                            const u8 *own_addr)
{
        struct wpa_driver_wired_data *drv = priv;
        struct ieee8023_hdr *hdr;
        size_t len;
        u8 *pos;
        int res;

        len = sizeof(*hdr) + data_len;
        hdr = os_zalloc(len);
        if (hdr == NULL) {
                printf("malloc() failed for wired_send_eapol(len=%lu)\n",
                       (unsigned long) len);
                return -1;
        }

        os_memcpy(hdr->dest, drv->use_pae_group_addr ? pae_group_addr : addr,
                  ETH_ALEN);
        os_memcpy(hdr->src, own_addr, ETH_ALEN);
        hdr->ethertype = htons(ETH_P_PAE);

        pos = (u8 *) (hdr + 1);
        os_memcpy(pos, data, data_len);

        res = send(drv->sock, (u8 *) hdr, len, 0);
        os_free(hdr);

        if (res < 0) {
                perror("wired_send_eapol: send");
                printf("wired_send_eapol - packet len: %lu - failed\n",
                       (unsigned long) len);
        }

        return res;
}


static void * wired_driver_hapd_init(struct hostapd_data *hapd,
                                     struct wpa_init_params *params)
{
        struct wpa_driver_wired_data *drv;

        drv = os_zalloc(sizeof(struct wpa_driver_wired_data));
        if (drv == NULL) {
                printf("Could not allocate memory for wired driver data\n");
                return NULL;
        }

        drv->ctx = hapd;
        os_strlcpy(drv->ifname, params->ifname, sizeof(drv->ifname));
        drv->use_pae_group_addr = params->use_pae_group_addr;

        if (wired_init_sockets(drv, params->own_addr)) {
                os_free(drv);
                return NULL;
        }

        return drv;
}


static void wired_driver_hapd_deinit(void *priv)
{
        struct wpa_driver_wired_data *drv = priv;

        if (drv->sock >= 0)
                close(drv->sock);

        if (drv->dhcp_sock >= 0)
                close(drv->dhcp_sock);

        os_free(drv);
}


static int wpa_driver_wired_get_ssid(void *priv, u8 *ssid)
{
        ssid[0] = 0;
        return 0;
}


static int wpa_driver_wired_get_bssid(void *priv, u8 *bssid)
{
        /* Report PAE group address as the "BSSID" for wired connection. */
        os_memcpy(bssid, pae_group_addr, ETH_ALEN);
        return 0;
}


static int wpa_driver_wired_get_capa(void *priv, struct wpa_driver_capa *capa)
{
        os_memset(capa, 0, sizeof(*capa));
        capa->flags = WPA_DRIVER_FLAGS_WIRED;
        return 0;
}


static int wpa_driver_wired_get_ifflags(const char *ifname, int *flags)
{
        struct ifreq ifr;
        int s;

        s = socket(PF_INET, SOCK_DGRAM, 0);
        if (s < 0) {
                perror("socket");
                return -1;
        }

        os_memset(&ifr, 0, sizeof(ifr));
        os_strlcpy(ifr.ifr_name, ifname, IFNAMSIZ);
        if (ioctl(s, SIOCGIFFLAGS, (caddr_t) &ifr) < 0) {
                perror("ioctl[SIOCGIFFLAGS]");
                close(s);
                return -1;
        }
        close(s);
        *flags = ifr.ifr_flags & 0xffff;
        return 0;
}


static int wpa_driver_wired_set_ifflags(const char *ifname, int flags)
{
        struct ifreq ifr;
        int s;

        s = socket(PF_INET, SOCK_DGRAM, 0);
        if (s < 0) {
                perror("socket");
                return -1;
        }

        os_memset(&ifr, 0, sizeof(ifr));
        os_strlcpy(ifr.ifr_name, ifname, IFNAMSIZ);
        ifr.ifr_flags = flags & 0xffff;
        if (ioctl(s, SIOCSIFFLAGS, (caddr_t) &ifr) < 0) {
                perror("ioctl[SIOCSIFFLAGS]");
                close(s);
                return -1;
        }
        close(s);
        return 0;
}


static int wpa_driver_wired_multi(const char *ifname, const u8 *addr, int add)
{
        struct ifreq ifr;
        int s;

        s = socket(PF_INET, SOCK_DGRAM, 0);
        if (s < 0) {
                perror("socket");
                return -1;
        }

        os_memset(&ifr, 0, sizeof(ifr));
        os_strlcpy(ifr.ifr_name, ifname, IFNAMSIZ);
#ifdef __linux__
        ifr.ifr_hwaddr.sa_family = AF_UNSPEC;
        os_memcpy(ifr.ifr_hwaddr.sa_data, addr, ETH_ALEN);
#endif /* __linux__ */
#if defined(__FreeBSD__) || defined(__DragonFly__) || defined(__FreeBSD_kernel__)
        {
                struct sockaddr_dl *dlp;
                dlp = (struct sockaddr_dl *) &ifr.ifr_addr;
                dlp->sdl_len = sizeof(struct sockaddr_dl);
                dlp->sdl_family = AF_LINK;
                dlp->sdl_index = 0;
                dlp->sdl_nlen = 0;
                dlp->sdl_alen = ETH_ALEN;
                dlp->sdl_slen = 0;
                os_memcpy(LLADDR(dlp), addr, ETH_ALEN);
        }
#endif /* defined(__FreeBSD__) || defined(__DragonFly__) || defined(FreeBSD_kernel__) */
#if defined(__NetBSD__) || defined(__OpenBSD__) || defined(__APPLE__)
        {
                struct sockaddr *sap;
                sap = (struct sockaddr *) &ifr.ifr_addr;
                sap->sa_len = sizeof(struct sockaddr);
                sap->sa_family = AF_UNSPEC;
                os_memcpy(sap->sa_data, addr, ETH_ALEN);
        }
#endif /* defined(__NetBSD__) || defined(__OpenBSD__) || defined(__APPLE__) */

        if (ioctl(s, add ? SIOCADDMULTI : SIOCDELMULTI, (caddr_t) &ifr) < 0) {
                perror("ioctl[SIOC{ADD/DEL}MULTI]");
                close(s);
                return -1;
        }
        close(s);
        return 0;
}


static void * wpa_driver_wired_init(void *ctx, const char *ifname)
{
        struct wpa_driver_wired_data *drv;
        int flags;

        drv = os_zalloc(sizeof(*drv));
        if (drv == NULL)
                return NULL;
        os_strlcpy(drv->ifname, ifname, sizeof(drv->ifname));
        drv->ctx = ctx;

#ifdef __linux__
        drv->pf_sock = socket(PF_PACKET, SOCK_DGRAM, 0);
        if (drv->pf_sock < 0)
                perror("socket(PF_PACKET)");
#else /* __linux__ */
        drv->pf_sock = -1;
#endif /* __linux__ */

        if (wpa_driver_wired_get_ifflags(ifname, &flags) == 0 &&
            !(flags & IFF_UP) &&
            wpa_driver_wired_set_ifflags(ifname, flags | IFF_UP) == 0) {
                drv->iff_up = 1;
        }

        if (wired_multicast_membership(drv->pf_sock,
                                       if_nametoindex(drv->ifname),
                                       pae_group_addr, 1) == 0) {
                wpa_printf(MSG_DEBUG, "%s: Added multicast membership with "
                           "packet socket", __func__);
                drv->membership = 1;
        } else if (wpa_driver_wired_multi(ifname, pae_group_addr, 1) == 0) {
                wpa_printf(MSG_DEBUG, "%s: Added multicast membership with "
                           "SIOCADDMULTI", __func__);
                drv->multi = 1;
        } else if (wpa_driver_wired_get_ifflags(ifname, &flags) < 0) {
                wpa_printf(MSG_INFO, "%s: Could not get interface "
                           "flags", __func__);
                os_free(drv);
                return NULL;
        } else if (flags & IFF_ALLMULTI) {
                wpa_printf(MSG_DEBUG, "%s: Interface is already configured "
                           "for multicast", __func__);
        } else if (wpa_driver_wired_set_ifflags(ifname,
                                                flags | IFF_ALLMULTI) < 0) {
                wpa_printf(MSG_INFO, "%s: Failed to enable allmulti",
                           __func__);
                os_free(drv);
                return NULL;
        } else {
                wpa_printf(MSG_DEBUG, "%s: Enabled allmulti mode",
                           __func__);
                drv->iff_allmulti = 1;
        }

        return drv;
}


static void wpa_driver_wired_deinit(void *priv)
{
        struct wpa_driver_wired_data *drv = priv;
        int flags;

        if (drv->membership &&
            wired_multicast_membership(drv->pf_sock,
                                       if_nametoindex(drv->ifname),
                                       pae_group_addr, 0) < 0) {
                wpa_printf(MSG_DEBUG, "%s: Failed to remove PAE multicast "
                           "group (PACKET)", __func__);
        }

        if (drv->multi &&
            wpa_driver_wired_multi(drv->ifname, pae_group_addr, 0) < 0) {
                wpa_printf(MSG_DEBUG, "%s: Failed to remove PAE multicast "
                           "group (SIOCDELMULTI)", __func__);
        }

        if (drv->iff_allmulti &&
            (wpa_driver_wired_get_ifflags(drv->ifname, &flags) < 0 ||
             wpa_driver_wired_set_ifflags(drv->ifname,
                                          flags & ~IFF_ALLMULTI) < 0)) {
                wpa_printf(MSG_DEBUG, "%s: Failed to disable allmulti mode",
                           __func__);
        }

        if (drv->iff_up &&
            wpa_driver_wired_get_ifflags(drv->ifname, &flags) == 0 &&
            (flags & IFF_UP) &&
            wpa_driver_wired_set_ifflags(drv->ifname, flags & ~IFF_UP) < 0) {
                wpa_printf(MSG_DEBUG, "%s: Failed to set the interface down",
                           __func__);
        }

        if (drv->pf_sock != -1)
                close(drv->pf_sock);

        os_free(drv);
}


const struct wpa_driver_ops wpa_driver_wired_ops = {
        .name = "wired",
        .desc = "Wired Ethernet driver",
        .hapd_init = wired_driver_hapd_init,
        .hapd_deinit = wired_driver_hapd_deinit,
        .hapd_send_eapol = wired_send_eapol,
        .get_ssid = wpa_driver_wired_get_ssid,
        .get_bssid = wpa_driver_wired_get_bssid,
        .get_capa = wpa_driver_wired_get_capa,
        .init = wpa_driver_wired_init,
        .deinit = wpa_driver_wired_deinit,
};