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/* vim: set expandtab ts=4 sw=4: */
/*
* You may redistribute this program and/or modify it under the terms of
* the GNU General Public License as published by the Free Software Foundation,
* either version 3 of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "interface/ETHInterface.h"
#include "exception/Except.h"
#include "memory/Allocator.h"
#include "net/InterfaceController.h"
#include "wire/Headers.h"
#include "wire/Message.h"
#include "wire/Error.h"
#include "wire/Ethernet.h"
#include "util/Assert.h"
#include "util/platform/Socket.h"
#include "util/events/Event.h"
#include "util/Identity.h"
#include "util/AddrTools.h"
#include "util/version/Version.h"
#include "util/events/Timeout.h"
#include <string.h>
#include <sys/socket.h>
#include <linux/if_packet.h>
#include <linux/if_ether.h>
#include <linux/if_arp.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <errno.h>
#ifndef android
#include <ifaddrs.h>
#endif
#define MAX_PACKET_SIZE 1496
#define MIN_PACKET_SIZE 46
#define PADDING 512
// 2 last 0x00 of .sll_addr are removed from original size (20)
#define SOCKADDR_LL_LEN 18
struct ETHInterface_pvt
{
struct ETHInterface pub;
Socket socket;
/** The unix interface index which is used to identify the eth device. */
int ifindex;
struct Log* logger;
struct sockaddr_ll addrBase;
String* ifName;
Identity
};
static void sendMessageInternal(struct Message* message,
struct sockaddr_ll* addr,
struct ETHInterface_pvt* context)
{
/* Cut down on the noise
uint8_t buff[sizeof(*addr) * 2 + 1] = {0};
Hex_encode(buff, sizeof(buff), (uint8_t*)addr, sizeof(*addr));
Log_debug(context->logger, "Sending ethernet frame to [%s]", buff);
*/
if (sendto(context->socket,
message->bytes,
message->length,
0,
(struct sockaddr*) addr,
sizeof(struct sockaddr_ll)) < 0)
{
switch (errno) {
default:;
Log_info(context->logger, "[%s] Got error sending to socket [%s]",
context->ifName->bytes, strerror(errno));
case EMSGSIZE:
case ENOBUFS:
case EAGAIN:;
// todo: care
}
}
return;
}
static Iface_DEFUN sendMessage(struct Message* msg, struct Iface* iface)
{
struct ETHInterface_pvt* ctx =
Identity_containerOf(iface, struct ETHInterface_pvt, pub.generic.iface);
struct Sockaddr* sa = (struct Sockaddr*) msg->bytes;
Assert_true(msg->length >= Sockaddr_OVERHEAD);
Assert_true(sa->addrLen <= ETHInterface_Sockaddr_SIZE);
struct ETHInterface_Sockaddr sockaddr = { .generic = { .addrLen = 0 } };
Message_pop(msg, &sockaddr, sa->addrLen, NULL);
struct sockaddr_ll addr;
Bits_memcpy(&addr, &ctx->addrBase, sizeof(struct sockaddr_ll));
if (sockaddr.generic.flags & Sockaddr_flags_BCAST) {
Bits_memset(addr.sll_addr, 0xff, 6);
} else {
Bits_memcpy(addr.sll_addr, sockaddr.mac, 6);
}
struct ETHInterface_Header hdr = {
.version = ETHInterface_CURRENT_VERSION,
.zero = 0,
.length_be = Endian_hostToBigEndian16(msg->length + ETHInterface_Header_SIZE),
.fc00_be = Endian_hostToBigEndian16(0xfc00)
};
Message_push(msg, &hdr, ETHInterface_Header_SIZE, NULL);
sendMessageInternal(msg, &addr, ctx);
return NULL;
}
static void handleEvent2(struct ETHInterface_pvt* context, struct Allocator* messageAlloc)
{
struct Message* msg = Message_new(MAX_PACKET_SIZE, PADDING, messageAlloc);
struct sockaddr_ll addr;
uint32_t addrLen = sizeof(struct sockaddr_ll);
// Knock it out of alignment by 2 bytes so that it will be
// aligned when the idAndPadding is shifted off.
Message_shift(msg, 2, NULL);
int rc = recvfrom(context->socket,
msg->bytes,
msg->length,
0,
(struct sockaddr*) &addr,
&addrLen);
if (rc < ETHInterface_Header_SIZE) {
Log_debug(context->logger, "Failed to receive eth frame");
return;
}
Assert_true(msg->length >= rc);
msg->length = rc;
//Assert_true(addrLen == SOCKADDR_LL_LEN);
struct ETHInterface_Header hdr;
Message_pop(msg, &hdr, ETHInterface_Header_SIZE, NULL);
// here we could put a switch statement to handle different versions differently.
if (hdr.version != ETHInterface_CURRENT_VERSION) {
Log_debug(context->logger, "DROP unknown version");
return;
}
uint16_t reportedLength = Endian_bigEndianToHost16(hdr.length_be);
reportedLength -= ETHInterface_Header_SIZE;
if (msg->length != reportedLength) {
if (msg->length < reportedLength) {
Log_debug(context->logger, "DROP size field is larger than frame");
return;
}
msg->length = reportedLength;
}
if (hdr.fc00_be != Endian_hostToBigEndian16(0xfc00)) {
Log_debug(context->logger, "DROP bad magic");
return;
}
struct ETHInterface_Sockaddr sockaddr = { .zero = 0 };
Bits_memcpy(sockaddr.mac, addr.sll_addr, 6);
sockaddr.generic.addrLen = ETHInterface_Sockaddr_SIZE;
if (addr.sll_pkttype == PACKET_BROADCAST) {
sockaddr.generic.flags |= Sockaddr_flags_BCAST;
}
Message_push(msg, &sockaddr, ETHInterface_Sockaddr_SIZE, NULL);
Assert_true(!((uintptr_t)msg->bytes % 4) && "Alignment fault");
Iface_send(&context->pub.generic.iface, msg);
}
static void handleEvent(void* vcontext)
{
struct ETHInterface_pvt* context = Identity_check((struct ETHInterface_pvt*) vcontext);
struct Allocator* messageAlloc = Allocator_child(context->pub.generic.alloc);
handleEvent2(context, messageAlloc);
Allocator_free(messageAlloc);
}
List* ETHInterface_listDevices(struct Allocator* alloc, struct Except* eh)
{
List* out = List_new(alloc);
#ifndef android
struct ifaddrs* ifaddr = NULL;
if (getifaddrs(&ifaddr) || ifaddr == NULL) {
Except_throw(eh, "getifaddrs() -> errno:%d [%s]", errno, strerror(errno));
}
for (struct ifaddrs* ifa = ifaddr; ifa; ifa = ifa->ifa_next) {
if (ifa->ifa_addr && ifa->ifa_addr->sa_family == AF_PACKET) {
List_addString(out, String_new(ifa->ifa_name, alloc), alloc);
}
}
freeifaddrs(ifaddr);
#endif
return out;
}
static int closeSocket(struct Allocator_OnFreeJob* j)
{
struct ETHInterface_pvt* ctx = Identity_check((struct ETHInterface_pvt*) j->userData);
close(ctx->socket);
return 0;
}
struct ETHInterface* ETHInterface_new(struct EventBase* eventBase,
const char* bindDevice,
struct Allocator* alloc,
struct Except* exHandler,
struct Log* logger)
{
struct ETHInterface_pvt* ctx = Allocator_calloc(alloc, sizeof(struct ETHInterface_pvt), 1);
Identity_set(ctx);
ctx->pub.generic.iface.send = sendMessage;
ctx->pub.generic.alloc = alloc;
ctx->logger = logger;
struct ifreq ifr = { .ifr_ifindex = 0 };
ctx->socket = socket(AF_PACKET, SOCK_DGRAM, Ethernet_TYPE_CJDNS);
if (ctx->socket == -1) {
Except_throw(exHandler, "call to socket() failed. [%s]", strerror(errno));
}
Allocator_onFree(alloc, closeSocket, ctx);
CString_strncpy(ifr.ifr_name, bindDevice, IFNAMSIZ - 1);
ctx->ifName = String_new(bindDevice, alloc);
if (ioctl(ctx->socket, SIOCGIFINDEX, &ifr) == -1) {
Except_throw(exHandler, "failed to find interface index [%s]", strerror(errno));
}
ctx->ifindex = ifr.ifr_ifindex;
if (ioctl(ctx->socket, SIOCGIFFLAGS, &ifr) < 0) {
Except_throw(exHandler, "ioctl(SIOCGIFFLAGS) [%s]", strerror(errno));
}
if (!((ifr.ifr_flags & IFF_UP) && (ifr.ifr_flags & IFF_RUNNING))) {
Log_info(logger, "Bringing up interface [%s]", ifr.ifr_name);
ifr.ifr_flags |= IFF_UP | IFF_RUNNING;
if (ioctl(ctx->socket, SIOCSIFFLAGS, &ifr) < 0) {
Except_throw(exHandler, "ioctl(SIOCSIFFLAGS) [%s]", strerror(errno));
}
}
ctx->addrBase = (struct sockaddr_ll) {
.sll_family = AF_PACKET,
.sll_protocol = Ethernet_TYPE_CJDNS,
.sll_ifindex = ctx->ifindex,
.sll_hatype = ARPHRD_ETHER,
.sll_pkttype = PACKET_OTHERHOST,
.sll_halen = ETH_ALEN
};
if (bind(ctx->socket, (struct sockaddr*) &ctx->addrBase, sizeof(struct sockaddr_ll))) {
Except_throw(exHandler, "call to bind() failed [%s]", strerror(errno));
}
Socket_makeNonBlocking(ctx->socket);
Event_socketRead(handleEvent, ctx, ctx->socket, eventBase, alloc, exHandler);
return &ctx->pub;
}
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