u-boot/arch/sandbox/cpu/eth-raw-os.c
Joe Hershberger 22f68524f8 sandbox: eth: Add support for using the 'lo' interface
The 'lo' interface on Linux doesn't support thinks like ARP or
link-layer access like we use to talk to a normal network interface.
A higher-level network API must be used to access localhost.

As written, this interface is limited to not supporting ICMP since the
API doesn't allow the socket to be opened for all IP traffic and be able
to receive at the same time. UDP is far more useful to test with, so it
was selected over ICMP. Ping won't work, but things like TFTP should
work.

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2015-04-18 11:11:14 -06:00

249 lines
6.7 KiB
C

/*
* Copyright (c) 2015 National Instruments
*
* (C) Copyright 2015
* Joe Hershberger <joe.hershberger@ni.com>
*
* SPDX-License-Identifier: GPL-2.0
*/
#include <asm/eth-raw-os.h>
#include <errno.h>
#include <fcntl.h>
#include <net/if.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/udp.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <linux/if_ether.h>
#include <linux/if_packet.h>
static int _raw_packet_start(const char *ifname, unsigned char *ethmac,
struct eth_sandbox_raw_priv *priv)
{
struct sockaddr_ll *device;
struct packet_mreq mr;
int ret;
int flags;
/* Prepare device struct */
priv->device = malloc(sizeof(struct sockaddr_ll));
if (priv->device == NULL)
return -ENOMEM;
device = priv->device;
memset(device, 0, sizeof(struct sockaddr_ll));
device->sll_ifindex = if_nametoindex(ifname);
device->sll_family = AF_PACKET;
memcpy(device->sll_addr, ethmac, 6);
device->sll_halen = htons(6);
/* Open socket */
priv->sd = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
if (priv->sd < 0) {
printf("Failed to open socket: %d %s\n", errno,
strerror(errno));
return -errno;
}
/* Bind to the specified interface */
ret = setsockopt(priv->sd, SOL_SOCKET, SO_BINDTODEVICE, ifname,
strlen(ifname) + 1);
if (ret < 0) {
printf("Failed to bind to '%s': %d %s\n", ifname, errno,
strerror(errno));
return -errno;
}
/* Make the socket non-blocking */
flags = fcntl(priv->sd, F_GETFL, 0);
fcntl(priv->sd, F_SETFL, flags | O_NONBLOCK);
/* Enable promiscuous mode to receive responses meant for us */
mr.mr_ifindex = device->sll_ifindex;
mr.mr_type = PACKET_MR_PROMISC;
ret = setsockopt(priv->sd, SOL_PACKET, PACKET_ADD_MEMBERSHIP,
&mr, sizeof(mr));
if (ret < 0) {
struct ifreq ifr;
printf("Failed to set promiscuous mode: %d %s\n"
"Falling back to the old \"flags\" way...\n",
errno, strerror(errno));
strncpy(ifr.ifr_name, ifname, IFNAMSIZ);
if (ioctl(priv->sd, SIOCGIFFLAGS, &ifr) < 0) {
printf("Failed to read flags: %d %s\n", errno,
strerror(errno));
return -errno;
}
ifr.ifr_flags |= IFF_PROMISC;
if (ioctl(priv->sd, SIOCSIFFLAGS, &ifr) < 0) {
printf("Failed to write flags: %d %s\n", errno,
strerror(errno));
return -errno;
}
}
return 0;
}
static int _local_inet_start(struct eth_sandbox_raw_priv *priv)
{
struct sockaddr_in *device;
int ret;
int flags;
int one = 1;
/* Prepare device struct */
priv->device = malloc(sizeof(struct sockaddr_in));
if (priv->device == NULL)
return -ENOMEM;
device = priv->device;
memset(device, 0, sizeof(struct sockaddr_in));
device->sin_family = AF_INET;
device->sin_addr.s_addr = htonl(INADDR_LOOPBACK);
/**
* Open socket
* Since we specify UDP here, any incoming ICMP packets will
* not be received, so things like ping will not work on this
* localhost interface.
*/
priv->sd = socket(AF_INET, SOCK_RAW, IPPROTO_UDP);
if (priv->sd < 0) {
printf("Failed to open socket: %d %s\n", errno,
strerror(errno));
return -errno;
}
/* Make the socket non-blocking */
flags = fcntl(priv->sd, F_GETFL, 0);
fcntl(priv->sd, F_SETFL, flags | O_NONBLOCK);
/* Include the UDP/IP headers on send and receive */
ret = setsockopt(priv->sd, IPPROTO_IP, IP_HDRINCL, &one,
sizeof(one));
if (ret < 0) {
printf("Failed to set header include option: %d %s\n", errno,
strerror(errno));
return -errno;
}
priv->local_bind_sd = -1;
priv->local_bind_udp_port = 0;
return 0;
}
int sandbox_eth_raw_os_start(const char *ifname, unsigned char *ethmac,
struct eth_sandbox_raw_priv *priv)
{
if (priv->local)
return _local_inet_start(priv);
else
return _raw_packet_start(ifname, ethmac, priv);
}
int sandbox_eth_raw_os_send(void *packet, int length,
struct eth_sandbox_raw_priv *priv)
{
int retval;
struct udphdr *udph = packet + sizeof(struct iphdr);
if (!priv->sd || !priv->device)
return -EINVAL;
/*
* This block of code came about when testing tftp on the localhost
* interface. When using the RAW AF_INET API, the network stack is still
* in play responding to incoming traffic based on open "ports". Since
* it is raw (at the IP layer, no Ethernet) the network stack tells the
* TFTP server that the port it responded to is closed. This causes the
* TFTP transfer to be aborted. This block of code inspects the outgoing
* packet as formulated by the u-boot network stack to determine the
* source port (that the TFTP server will send packets back to) and
* opens a typical UDP socket on that port, thus preventing the network
* stack from sending that ICMP message claiming that the port has no
* bound socket.
*/
if (priv->local && (priv->local_bind_sd == -1 ||
priv->local_bind_udp_port != udph->source)) {
struct iphdr *iph = packet;
struct sockaddr_in addr;
if (priv->local_bind_sd != -1)
close(priv->local_bind_sd);
/* A normal UDP socket is required to bind */
priv->local_bind_sd = socket(AF_INET, SOCK_DGRAM, 0);
if (priv->local_bind_sd < 0) {
printf("Failed to open bind sd: %d %s\n", errno,
strerror(errno));
return -errno;
}
priv->local_bind_udp_port = udph->source;
/**
* Bind the UDP port that we intend to use as our source port
* so that the kernel will not send an ICMP port unreachable
* message to the server
*/
addr.sin_family = AF_INET;
addr.sin_port = udph->source;
addr.sin_addr.s_addr = iph->saddr;
retval = bind(priv->local_bind_sd, &addr, sizeof(addr));
if (retval < 0)
printf("Failed to bind: %d %s\n", errno,
strerror(errno));
}
retval = sendto(priv->sd, packet, length, 0,
(struct sockaddr *)priv->device,
sizeof(struct sockaddr_ll));
if (retval < 0) {
printf("Failed to send packet: %d %s\n", errno,
strerror(errno));
return -errno;
}
return retval;
}
int sandbox_eth_raw_os_recv(void *packet, int *length,
const struct eth_sandbox_raw_priv *priv)
{
int retval;
int saddr_size;
if (!priv->sd || !priv->device)
return -EINVAL;
saddr_size = sizeof(struct sockaddr);
retval = recvfrom(priv->sd, packet, 1536, 0,
(struct sockaddr *)priv->device,
(socklen_t *)&saddr_size);
*length = 0;
if (retval >= 0) {
*length = retval;
return 0;
}
/* The socket is non-blocking, so expect EAGAIN when there is no data */
if (errno == EAGAIN)
return 0;
return -errno;
}
void sandbox_eth_raw_os_stop(struct eth_sandbox_raw_priv *priv)
{
free(priv->device);
priv->device = NULL;
close(priv->sd);
priv->sd = -1;
if (priv->local) {
if (priv->local_bind_sd != -1)
close(priv->local_bind_sd);
priv->local_bind_sd = -1;
priv->local_bind_udp_port = 0;
}
}