1 /* 2 * Copyright (c) 2015 National Instruments 3 * 4 * (C) Copyright 2015 5 * Joe Hershberger <joe.hershberger@ni.com> 6 * 7 * SPDX-License-Identifier: GPL-2.0 8 */ 9 10 #include <asm/eth-raw-os.h> 11 #include <errno.h> 12 #include <fcntl.h> 13 #include <net/if.h> 14 #include <netinet/in.h> 15 #include <netinet/ip.h> 16 #include <netinet/udp.h> 17 #include <stdio.h> 18 #include <stdlib.h> 19 #include <string.h> 20 #include <sys/types.h> 21 #include <sys/ioctl.h> 22 #include <sys/socket.h> 23 #include <unistd.h> 24 25 #include <arpa/inet.h> 26 #include <linux/if_ether.h> 27 #include <linux/if_packet.h> 28 29 static int _raw_packet_start(const char *ifname, unsigned char *ethmac, 30 struct eth_sandbox_raw_priv *priv) 31 { 32 struct sockaddr_ll *device; 33 struct packet_mreq mr; 34 int ret; 35 int flags; 36 37 /* Prepare device struct */ 38 priv->device = malloc(sizeof(struct sockaddr_ll)); 39 if (priv->device == NULL) 40 return -ENOMEM; 41 device = priv->device; 42 memset(device, 0, sizeof(struct sockaddr_ll)); 43 device->sll_ifindex = if_nametoindex(ifname); 44 device->sll_family = AF_PACKET; 45 memcpy(device->sll_addr, ethmac, 6); 46 device->sll_halen = htons(6); 47 48 /* Open socket */ 49 priv->sd = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL)); 50 if (priv->sd < 0) { 51 printf("Failed to open socket: %d %s\n", errno, 52 strerror(errno)); 53 return -errno; 54 } 55 /* Bind to the specified interface */ 56 ret = setsockopt(priv->sd, SOL_SOCKET, SO_BINDTODEVICE, ifname, 57 strlen(ifname) + 1); 58 if (ret < 0) { 59 printf("Failed to bind to '%s': %d %s\n", ifname, errno, 60 strerror(errno)); 61 return -errno; 62 } 63 64 /* Make the socket non-blocking */ 65 flags = fcntl(priv->sd, F_GETFL, 0); 66 fcntl(priv->sd, F_SETFL, flags | O_NONBLOCK); 67 68 /* Enable promiscuous mode to receive responses meant for us */ 69 mr.mr_ifindex = device->sll_ifindex; 70 mr.mr_type = PACKET_MR_PROMISC; 71 ret = setsockopt(priv->sd, SOL_PACKET, PACKET_ADD_MEMBERSHIP, 72 &mr, sizeof(mr)); 73 if (ret < 0) { 74 struct ifreq ifr; 75 76 printf("Failed to set promiscuous mode: %d %s\n" 77 "Falling back to the old \"flags\" way...\n", 78 errno, strerror(errno)); 79 strncpy(ifr.ifr_name, ifname, IFNAMSIZ); 80 if (ioctl(priv->sd, SIOCGIFFLAGS, &ifr) < 0) { 81 printf("Failed to read flags: %d %s\n", errno, 82 strerror(errno)); 83 return -errno; 84 } 85 ifr.ifr_flags |= IFF_PROMISC; 86 if (ioctl(priv->sd, SIOCSIFFLAGS, &ifr) < 0) { 87 printf("Failed to write flags: %d %s\n", errno, 88 strerror(errno)); 89 return -errno; 90 } 91 } 92 return 0; 93 } 94 95 static int _local_inet_start(struct eth_sandbox_raw_priv *priv) 96 { 97 struct sockaddr_in *device; 98 int ret; 99 int flags; 100 int one = 1; 101 102 /* Prepare device struct */ 103 priv->device = malloc(sizeof(struct sockaddr_in)); 104 if (priv->device == NULL) 105 return -ENOMEM; 106 device = priv->device; 107 memset(device, 0, sizeof(struct sockaddr_in)); 108 device->sin_family = AF_INET; 109 device->sin_addr.s_addr = htonl(INADDR_LOOPBACK); 110 111 /** 112 * Open socket 113 * Since we specify UDP here, any incoming ICMP packets will 114 * not be received, so things like ping will not work on this 115 * localhost interface. 116 */ 117 priv->sd = socket(AF_INET, SOCK_RAW, IPPROTO_UDP); 118 if (priv->sd < 0) { 119 printf("Failed to open socket: %d %s\n", errno, 120 strerror(errno)); 121 return -errno; 122 } 123 124 /* Make the socket non-blocking */ 125 flags = fcntl(priv->sd, F_GETFL, 0); 126 fcntl(priv->sd, F_SETFL, flags | O_NONBLOCK); 127 128 /* Include the UDP/IP headers on send and receive */ 129 ret = setsockopt(priv->sd, IPPROTO_IP, IP_HDRINCL, &one, 130 sizeof(one)); 131 if (ret < 0) { 132 printf("Failed to set header include option: %d %s\n", errno, 133 strerror(errno)); 134 return -errno; 135 } 136 priv->local_bind_sd = -1; 137 priv->local_bind_udp_port = 0; 138 return 0; 139 } 140 141 int sandbox_eth_raw_os_start(const char *ifname, unsigned char *ethmac, 142 struct eth_sandbox_raw_priv *priv) 143 { 144 if (priv->local) 145 return _local_inet_start(priv); 146 else 147 return _raw_packet_start(ifname, ethmac, priv); 148 } 149 150 int sandbox_eth_raw_os_send(void *packet, int length, 151 struct eth_sandbox_raw_priv *priv) 152 { 153 int retval; 154 struct udphdr *udph = packet + sizeof(struct iphdr); 155 156 if (!priv->sd || !priv->device) 157 return -EINVAL; 158 159 /* 160 * This block of code came about when testing tftp on the localhost 161 * interface. When using the RAW AF_INET API, the network stack is still 162 * in play responding to incoming traffic based on open "ports". Since 163 * it is raw (at the IP layer, no Ethernet) the network stack tells the 164 * TFTP server that the port it responded to is closed. This causes the 165 * TFTP transfer to be aborted. This block of code inspects the outgoing 166 * packet as formulated by the u-boot network stack to determine the 167 * source port (that the TFTP server will send packets back to) and 168 * opens a typical UDP socket on that port, thus preventing the network 169 * stack from sending that ICMP message claiming that the port has no 170 * bound socket. 171 */ 172 if (priv->local && (priv->local_bind_sd == -1 || 173 priv->local_bind_udp_port != udph->source)) { 174 struct iphdr *iph = packet; 175 struct sockaddr_in addr; 176 177 if (priv->local_bind_sd != -1) 178 close(priv->local_bind_sd); 179 180 /* A normal UDP socket is required to bind */ 181 priv->local_bind_sd = socket(AF_INET, SOCK_DGRAM, 0); 182 if (priv->local_bind_sd < 0) { 183 printf("Failed to open bind sd: %d %s\n", errno, 184 strerror(errno)); 185 return -errno; 186 } 187 priv->local_bind_udp_port = udph->source; 188 189 /** 190 * Bind the UDP port that we intend to use as our source port 191 * so that the kernel will not send an ICMP port unreachable 192 * message to the server 193 */ 194 addr.sin_family = AF_INET; 195 addr.sin_port = udph->source; 196 addr.sin_addr.s_addr = iph->saddr; 197 retval = bind(priv->local_bind_sd, &addr, sizeof(addr)); 198 if (retval < 0) 199 printf("Failed to bind: %d %s\n", errno, 200 strerror(errno)); 201 } 202 203 retval = sendto(priv->sd, packet, length, 0, 204 (struct sockaddr *)priv->device, 205 sizeof(struct sockaddr_ll)); 206 if (retval < 0) { 207 printf("Failed to send packet: %d %s\n", errno, 208 strerror(errno)); 209 return -errno; 210 } 211 return retval; 212 } 213 214 int sandbox_eth_raw_os_recv(void *packet, int *length, 215 const struct eth_sandbox_raw_priv *priv) 216 { 217 int retval; 218 int saddr_size; 219 220 if (!priv->sd || !priv->device) 221 return -EINVAL; 222 saddr_size = sizeof(struct sockaddr); 223 retval = recvfrom(priv->sd, packet, 1536, 0, 224 (struct sockaddr *)priv->device, 225 (socklen_t *)&saddr_size); 226 *length = 0; 227 if (retval >= 0) { 228 *length = retval; 229 return 0; 230 } 231 /* The socket is non-blocking, so expect EAGAIN when there is no data */ 232 if (errno == EAGAIN) 233 return 0; 234 return -errno; 235 } 236 237 void sandbox_eth_raw_os_stop(struct eth_sandbox_raw_priv *priv) 238 { 239 free(priv->device); 240 priv->device = NULL; 241 close(priv->sd); 242 priv->sd = -1; 243 if (priv->local) { 244 if (priv->local_bind_sd != -1) 245 close(priv->local_bind_sd); 246 priv->local_bind_sd = -1; 247 priv->local_bind_udp_port = 0; 248 } 249 } 250