Viacheslav Mitrofanov | c6610e1 | 2022-12-02 12:18:01 +0300 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0+ |
| 2 | /* |
| 3 | * Copyright (C) 2013 Allied Telesis Labs NZ |
| 4 | * Chris Packham, <judge.packham@gmail.com> |
| 5 | * |
| 6 | * Copyright (C) 2022 YADRO |
| 7 | * Viacheslav Mitrofanov <v.v.mitrofanov@yadro.com> |
| 8 | */ |
| 9 | |
| 10 | /* Neighbour Discovery for IPv6 */ |
| 11 | |
| 12 | #include <common.h> |
| 13 | #include <net.h> |
| 14 | #include <net6.h> |
| 15 | #include <ndisc.h> |
Ehsan Mohandesi | 6de98b6 | 2023-04-21 17:08:21 -0700 | [diff] [blame] | 16 | #include <stdlib.h> |
| 17 | #include <linux/delay.h> |
Viacheslav Mitrofanov | c6610e1 | 2022-12-02 12:18:01 +0300 | [diff] [blame] | 18 | |
| 19 | /* IPv6 destination address of packet waiting for ND */ |
| 20 | struct in6_addr net_nd_sol_packet_ip6 = ZERO_IPV6_ADDR; |
| 21 | /* IPv6 address we are expecting ND advert from */ |
| 22 | static struct in6_addr net_nd_rep_packet_ip6 = ZERO_IPV6_ADDR; |
| 23 | /* MAC destination address of packet waiting for ND */ |
| 24 | uchar *net_nd_packet_mac; |
| 25 | /* pointer to packet waiting to be transmitted after ND is resolved */ |
| 26 | uchar *net_nd_tx_packet; |
| 27 | static uchar net_nd_packet_buf[PKTSIZE_ALIGN + PKTALIGN]; |
| 28 | /* size of packet waiting to be transmitted */ |
| 29 | int net_nd_tx_packet_size; |
| 30 | /* the timer for ND resolution */ |
| 31 | ulong net_nd_timer_start; |
| 32 | /* the number of requests we have sent so far */ |
| 33 | int net_nd_try; |
Ehsan Mohandesi | 6de98b6 | 2023-04-21 17:08:21 -0700 | [diff] [blame] | 34 | struct in6_addr all_routers = ALL_ROUTERS_MULT_ADDR; |
| 35 | |
| 36 | #define MAX_RTR_SOLICITATIONS 3 |
| 37 | /* The maximum time to delay sending the first router solicitation message. */ |
| 38 | #define MAX_SOLICITATION_DELAY 1 // 1 second |
| 39 | /* The time to wait before sending the next router solicitation message. */ |
| 40 | #define RTR_SOLICITATION_INTERVAL 4000 // 4 seconds |
Viacheslav Mitrofanov | c6610e1 | 2022-12-02 12:18:01 +0300 | [diff] [blame] | 41 | |
| 42 | #define IP6_NDISC_OPT_SPACE(len) (((len) + 2 + 7) & ~7) |
| 43 | |
| 44 | /** |
| 45 | * ndisc_insert_option() - Insert an option into a neighbor discovery packet |
| 46 | * |
Ehsan Mohandesi | 6de98b6 | 2023-04-21 17:08:21 -0700 | [diff] [blame] | 47 | * @opt: pointer to the option element of the neighbor discovery packet |
Viacheslav Mitrofanov | c6610e1 | 2022-12-02 12:18:01 +0300 | [diff] [blame] | 48 | * @type: option type to insert |
| 49 | * @data: option data to insert |
| 50 | * @len: data length |
| 51 | * Return: the number of bytes inserted (which may be >= len) |
| 52 | */ |
Ehsan Mohandesi | 6de98b6 | 2023-04-21 17:08:21 -0700 | [diff] [blame] | 53 | static int ndisc_insert_option(__u8 *opt, int type, u8 *data, int len) |
Viacheslav Mitrofanov | c6610e1 | 2022-12-02 12:18:01 +0300 | [diff] [blame] | 54 | { |
| 55 | int space = IP6_NDISC_OPT_SPACE(len); |
| 56 | |
Ehsan Mohandesi | 6de98b6 | 2023-04-21 17:08:21 -0700 | [diff] [blame] | 57 | opt[0] = type; |
| 58 | opt[1] = space >> 3; |
| 59 | memcpy(&opt[2], data, len); |
Viacheslav Mitrofanov | c6610e1 | 2022-12-02 12:18:01 +0300 | [diff] [blame] | 60 | len += 2; |
| 61 | |
| 62 | /* fill the remainder with 0 */ |
| 63 | if (space - len > 0) |
Ehsan Mohandesi | 6de98b6 | 2023-04-21 17:08:21 -0700 | [diff] [blame] | 64 | memset(&opt[len], '\0', space - len); |
Viacheslav Mitrofanov | c6610e1 | 2022-12-02 12:18:01 +0300 | [diff] [blame] | 65 | |
| 66 | return space; |
| 67 | } |
| 68 | |
| 69 | /** |
| 70 | * ndisc_extract_enetaddr() - Extract the Ethernet address from a ND packet |
| 71 | * |
| 72 | * Note that the link layer address could be anything but the only networking |
| 73 | * media that u-boot supports is Ethernet so we assume we're extracting a 6 |
| 74 | * byte Ethernet MAC address. |
| 75 | * |
| 76 | * @ndisc: pointer to ND packet |
| 77 | * @enetaddr: extracted MAC addr |
| 78 | */ |
| 79 | static void ndisc_extract_enetaddr(struct nd_msg *ndisc, uchar enetaddr[6]) |
| 80 | { |
| 81 | memcpy(enetaddr, &ndisc->opt[2], 6); |
| 82 | } |
| 83 | |
| 84 | /** |
| 85 | * ndisc_has_option() - Check if the ND packet has the specified option set |
| 86 | * |
| 87 | * @ip6: pointer to IPv6 header |
| 88 | * @type: option type to check |
| 89 | * Return: 1 if ND has that option, 0 therwise |
| 90 | */ |
| 91 | static int ndisc_has_option(struct ip6_hdr *ip6, __u8 type) |
| 92 | { |
| 93 | struct nd_msg *ndisc = (struct nd_msg *)(((uchar *)ip6) + IP6_HDR_SIZE); |
| 94 | |
| 95 | if (ip6->payload_len <= sizeof(struct icmp6hdr)) |
| 96 | return 0; |
| 97 | |
| 98 | return ndisc->opt[0] == type; |
| 99 | } |
| 100 | |
| 101 | static void ip6_send_ns(struct in6_addr *neigh_addr) |
| 102 | { |
| 103 | struct in6_addr dst_adr; |
| 104 | unsigned char enetaddr[6]; |
| 105 | struct nd_msg *msg; |
| 106 | __u16 len; |
| 107 | uchar *pkt; |
| 108 | unsigned short csum; |
| 109 | unsigned int pcsum; |
| 110 | |
| 111 | debug("sending neighbor solicitation for %pI6c our address %pI6c\n", |
| 112 | neigh_addr, &net_link_local_ip6); |
| 113 | |
| 114 | /* calculate src, dest IPv6 addr and dest Eth addr */ |
| 115 | ip6_make_snma(&dst_adr, neigh_addr); |
| 116 | ip6_make_mult_ethdstaddr(enetaddr, &dst_adr); |
| 117 | len = sizeof(struct icmp6hdr) + IN6ADDRSZ + |
| 118 | IP6_NDISC_OPT_SPACE(INETHADDRSZ); |
| 119 | |
| 120 | pkt = (uchar *)net_tx_packet; |
| 121 | pkt += net_set_ether(pkt, enetaddr, PROT_IP6); |
| 122 | pkt += ip6_add_hdr(pkt, &net_link_local_ip6, &dst_adr, PROT_ICMPV6, |
| 123 | IPV6_NDISC_HOPLIMIT, len); |
| 124 | |
| 125 | /* ICMPv6 - NS */ |
| 126 | msg = (struct nd_msg *)pkt; |
| 127 | msg->icmph.icmp6_type = IPV6_NDISC_NEIGHBOUR_SOLICITATION; |
| 128 | msg->icmph.icmp6_code = 0; |
| 129 | memset(&msg->icmph.icmp6_cksum, 0, sizeof(__be16)); |
| 130 | memset(&msg->icmph.icmp6_unused, 0, sizeof(__be32)); |
| 131 | |
| 132 | /* Set the target address and llsaddr option */ |
| 133 | net_copy_ip6(&msg->target, neigh_addr); |
Ehsan Mohandesi | 6de98b6 | 2023-04-21 17:08:21 -0700 | [diff] [blame] | 134 | ndisc_insert_option(msg->opt, ND_OPT_SOURCE_LL_ADDR, net_ethaddr, |
Viacheslav Mitrofanov | c6610e1 | 2022-12-02 12:18:01 +0300 | [diff] [blame] | 135 | INETHADDRSZ); |
| 136 | |
| 137 | /* checksum */ |
| 138 | pcsum = csum_partial((__u8 *)msg, len, 0); |
| 139 | csum = csum_ipv6_magic(&net_link_local_ip6, &dst_adr, |
| 140 | len, PROT_ICMPV6, pcsum); |
| 141 | msg->icmph.icmp6_cksum = csum; |
| 142 | pkt += len; |
| 143 | |
| 144 | /* send it! */ |
| 145 | net_send_packet(net_tx_packet, (pkt - net_tx_packet)); |
| 146 | } |
| 147 | |
Ehsan Mohandesi | 6de98b6 | 2023-04-21 17:08:21 -0700 | [diff] [blame] | 148 | /* |
| 149 | * ip6_send_rs() - Send IPv6 Router Solicitation Message. |
| 150 | * |
| 151 | * A router solicitation is sent to discover a router. RS message creation is |
| 152 | * based on RFC 4861 section 4.1. Router Solicitation Message Format. |
| 153 | */ |
| 154 | void ip6_send_rs(void) |
| 155 | { |
| 156 | unsigned char enetaddr[6]; |
| 157 | struct rs_msg *msg; |
| 158 | __u16 icmp_len; |
| 159 | uchar *pkt; |
| 160 | unsigned short csum; |
| 161 | unsigned int pcsum; |
| 162 | static unsigned int retry_count; |
| 163 | |
| 164 | if (!ip6_is_unspecified_addr(&net_gateway6) && |
| 165 | net_prefix_length != 0) { |
| 166 | net_set_state(NETLOOP_SUCCESS); |
| 167 | return; |
| 168 | } else if (retry_count >= MAX_RTR_SOLICITATIONS) { |
| 169 | net_set_state(NETLOOP_FAIL); |
| 170 | net_set_timeout_handler(0, NULL); |
| 171 | retry_count = 0; |
| 172 | return; |
| 173 | } |
| 174 | |
| 175 | printf("ROUTER SOLICITATION %d\n", retry_count + 1); |
| 176 | |
| 177 | ip6_make_mult_ethdstaddr(enetaddr, &all_routers); |
| 178 | /* |
| 179 | * ICMP length is the size of ICMP header (8) + one option (8) = 16. |
| 180 | * The option is 2 bytes of type and length + 6 bytes for MAC. |
| 181 | */ |
| 182 | icmp_len = sizeof(struct icmp6hdr) + IP6_NDISC_OPT_SPACE(INETHADDRSZ); |
| 183 | |
| 184 | pkt = (uchar *)net_tx_packet; |
| 185 | pkt += net_set_ether(pkt, enetaddr, PROT_IP6); |
| 186 | pkt += ip6_add_hdr(pkt, &net_link_local_ip6, &all_routers, PROT_ICMPV6, |
| 187 | IPV6_NDISC_HOPLIMIT, icmp_len); |
| 188 | |
| 189 | /* ICMPv6 - RS */ |
| 190 | msg = (struct rs_msg *)pkt; |
| 191 | msg->icmph.icmp6_type = IPV6_NDISC_ROUTER_SOLICITATION; |
| 192 | msg->icmph.icmp6_code = 0; |
| 193 | memset(&msg->icmph.icmp6_cksum, 0, sizeof(__be16)); |
| 194 | memset(&msg->icmph.icmp6_unused, 0, sizeof(__be32)); |
| 195 | |
| 196 | /* Set the llsaddr option */ |
| 197 | ndisc_insert_option(msg->opt, ND_OPT_SOURCE_LL_ADDR, net_ethaddr, |
| 198 | INETHADDRSZ); |
| 199 | |
| 200 | /* checksum */ |
| 201 | pcsum = csum_partial((__u8 *)msg, icmp_len, 0); |
| 202 | csum = csum_ipv6_magic(&net_link_local_ip6, &all_routers, |
| 203 | icmp_len, PROT_ICMPV6, pcsum); |
| 204 | msg->icmph.icmp6_cksum = csum; |
| 205 | pkt += icmp_len; |
| 206 | |
| 207 | /* Wait up to 1 second if it is the first try to get the RA */ |
| 208 | if (retry_count == 0) |
| 209 | udelay(((unsigned int)rand() % 1000000) * MAX_SOLICITATION_DELAY); |
| 210 | |
| 211 | /* send it! */ |
| 212 | net_send_packet(net_tx_packet, (pkt - net_tx_packet)); |
| 213 | |
| 214 | retry_count++; |
| 215 | net_set_timeout_handler(RTR_SOLICITATION_INTERVAL, ip6_send_rs); |
| 216 | } |
| 217 | |
Viacheslav Mitrofanov | c6610e1 | 2022-12-02 12:18:01 +0300 | [diff] [blame] | 218 | static void |
| 219 | ip6_send_na(uchar *eth_dst_addr, struct in6_addr *neigh_addr, |
| 220 | struct in6_addr *target) |
| 221 | { |
| 222 | struct nd_msg *msg; |
| 223 | __u16 len; |
| 224 | uchar *pkt; |
| 225 | unsigned short csum; |
| 226 | |
| 227 | debug("sending neighbor advertisement for %pI6c to %pI6c (%pM)\n", |
| 228 | target, neigh_addr, eth_dst_addr); |
| 229 | |
| 230 | len = sizeof(struct icmp6hdr) + IN6ADDRSZ + |
| 231 | IP6_NDISC_OPT_SPACE(INETHADDRSZ); |
| 232 | |
| 233 | pkt = (uchar *)net_tx_packet; |
| 234 | pkt += net_set_ether(pkt, eth_dst_addr, PROT_IP6); |
| 235 | pkt += ip6_add_hdr(pkt, &net_link_local_ip6, neigh_addr, |
| 236 | PROT_ICMPV6, IPV6_NDISC_HOPLIMIT, len); |
| 237 | |
| 238 | /* ICMPv6 - NA */ |
| 239 | msg = (struct nd_msg *)pkt; |
| 240 | msg->icmph.icmp6_type = IPV6_NDISC_NEIGHBOUR_ADVERTISEMENT; |
| 241 | msg->icmph.icmp6_code = 0; |
| 242 | memset(&msg->icmph.icmp6_cksum, 0, sizeof(__be16)); |
| 243 | memset(&msg->icmph.icmp6_unused, 0, sizeof(__be32)); |
| 244 | msg->icmph.icmp6_dataun.u_nd_advt.solicited = 1; |
| 245 | msg->icmph.icmp6_dataun.u_nd_advt.override = 1; |
| 246 | /* Set the target address and lltargetaddr option */ |
| 247 | net_copy_ip6(&msg->target, target); |
Ehsan Mohandesi | 6de98b6 | 2023-04-21 17:08:21 -0700 | [diff] [blame] | 248 | ndisc_insert_option(msg->opt, ND_OPT_TARGET_LL_ADDR, net_ethaddr, |
Viacheslav Mitrofanov | c6610e1 | 2022-12-02 12:18:01 +0300 | [diff] [blame] | 249 | INETHADDRSZ); |
| 250 | |
| 251 | /* checksum */ |
| 252 | csum = csum_ipv6_magic(&net_link_local_ip6, |
| 253 | neigh_addr, len, PROT_ICMPV6, |
| 254 | csum_partial((__u8 *)msg, len, 0)); |
| 255 | msg->icmph.icmp6_cksum = csum; |
| 256 | pkt += len; |
| 257 | |
| 258 | /* send it! */ |
| 259 | net_send_packet(net_tx_packet, (pkt - net_tx_packet)); |
| 260 | } |
| 261 | |
| 262 | void ndisc_request(void) |
| 263 | { |
| 264 | if (!ip6_addr_in_subnet(&net_ip6, &net_nd_sol_packet_ip6, |
| 265 | net_prefix_length)) { |
| 266 | if (ip6_is_unspecified_addr(&net_gateway6)) { |
| 267 | puts("## Warning: gatewayip6 is needed but not set\n"); |
| 268 | net_nd_rep_packet_ip6 = net_nd_sol_packet_ip6; |
| 269 | } else { |
| 270 | net_nd_rep_packet_ip6 = net_gateway6; |
| 271 | } |
| 272 | } else { |
| 273 | net_nd_rep_packet_ip6 = net_nd_sol_packet_ip6; |
| 274 | } |
| 275 | |
| 276 | ip6_send_ns(&net_nd_rep_packet_ip6); |
| 277 | } |
| 278 | |
| 279 | int ndisc_timeout_check(void) |
| 280 | { |
| 281 | ulong t; |
| 282 | |
| 283 | if (ip6_is_unspecified_addr(&net_nd_sol_packet_ip6)) |
| 284 | return 0; |
| 285 | |
| 286 | t = get_timer(0); |
| 287 | |
| 288 | /* check for NDISC timeout */ |
| 289 | if ((t - net_nd_timer_start) > NDISC_TIMEOUT) { |
| 290 | net_nd_try++; |
| 291 | if (net_nd_try >= NDISC_TIMEOUT_COUNT) { |
| 292 | puts("\nNeighbour discovery retry count exceeded; " |
| 293 | "starting again\n"); |
| 294 | net_nd_try = 0; |
| 295 | net_set_state(NETLOOP_FAIL); |
| 296 | } else { |
| 297 | net_nd_timer_start = t; |
| 298 | ndisc_request(); |
| 299 | } |
| 300 | } |
| 301 | return 1; |
| 302 | } |
| 303 | |
Ehsan Mohandesi | 6de98b6 | 2023-04-21 17:08:21 -0700 | [diff] [blame] | 304 | /* |
| 305 | * ndisc_init() - Make initial steps for ND state machine. |
| 306 | * Usually move variables into initial state. |
| 307 | */ |
Viacheslav Mitrofanov | c6610e1 | 2022-12-02 12:18:01 +0300 | [diff] [blame] | 308 | void ndisc_init(void) |
| 309 | { |
| 310 | net_nd_packet_mac = NULL; |
| 311 | net_nd_tx_packet = NULL; |
| 312 | net_nd_sol_packet_ip6 = net_null_addr_ip6; |
| 313 | net_nd_rep_packet_ip6 = net_null_addr_ip6; |
| 314 | net_nd_tx_packet_size = 0; |
| 315 | net_nd_tx_packet = &net_nd_packet_buf[0] + (PKTALIGN - 1); |
| 316 | net_nd_tx_packet -= (ulong)net_nd_tx_packet % PKTALIGN; |
| 317 | } |
| 318 | |
Ehsan Mohandesi | 6de98b6 | 2023-04-21 17:08:21 -0700 | [diff] [blame] | 319 | /* |
| 320 | * validate_ra() - Validate the router advertisement message. |
| 321 | * |
| 322 | * @ip6: Pointer to the router advertisement packet |
| 323 | * |
| 324 | * Check if the router advertisement message is valid. Conditions are |
| 325 | * according to RFC 4861 section 6.1.2. Validation of Router Advertisement |
| 326 | * Messages. |
| 327 | * |
| 328 | * Return: true if the message is valid and false if it is invalid. |
| 329 | */ |
| 330 | bool validate_ra(struct ip6_hdr *ip6) |
| 331 | { |
| 332 | struct icmp6hdr *icmp = (struct icmp6hdr *)(ip6 + 1); |
| 333 | |
| 334 | /* ICMP length (derived from the IP length) should be 16 or more octets. */ |
| 335 | if (ip6->payload_len < 16) |
| 336 | return false; |
| 337 | |
| 338 | /* Source IP Address should be a valid link-local address. */ |
| 339 | if ((ntohs(ip6->saddr.s6_addr16[0]) & IPV6_LINK_LOCAL_MASK) != |
| 340 | IPV6_LINK_LOCAL_PREFIX) |
| 341 | return false; |
| 342 | |
| 343 | /* |
| 344 | * The IP Hop Limit field should have a value of 255, i.e., the packet |
| 345 | * could not possibly have been forwarded by a router. |
| 346 | */ |
| 347 | if (ip6->hop_limit != 255) |
| 348 | return false; |
| 349 | |
| 350 | /* ICMP checksum has already been checked in net_ip6_handler. */ |
| 351 | |
| 352 | if (icmp->icmp6_code != 0) |
| 353 | return false; |
| 354 | |
| 355 | return true; |
| 356 | } |
| 357 | |
| 358 | /* |
| 359 | * process_ra() - Process the router advertisement packet. |
| 360 | * |
| 361 | * @ip6: Pointer to the router advertisement packet |
| 362 | * @len: Length of the router advertisement packet |
| 363 | * |
| 364 | * Process the received router advertisement message. |
| 365 | * Although RFC 4861 requires retaining at least two router addresses, we only |
| 366 | * keep one because of the U-Boot limitations and its goal of lightweight code. |
| 367 | * |
| 368 | * Return: 0 - RA is a default router and contains valid prefix information. |
| 369 | * Non-zero - RA options are invalid or do not indicate it is a default router |
| 370 | * or do not contain valid prefix information. |
| 371 | */ |
| 372 | int process_ra(struct ip6_hdr *ip6, int len) |
| 373 | { |
| 374 | /* Pointer to the ICMP section of the packet */ |
| 375 | struct icmp6hdr *icmp = (struct icmp6hdr *)(ip6 + 1); |
| 376 | struct ra_msg *msg = (struct ra_msg *)icmp; |
| 377 | int remaining_option_len = len - IP6_HDR_SIZE - sizeof(struct ra_msg); |
| 378 | unsigned short int option_len; /* Length of each option */ |
| 379 | /* Pointer to the ICMPv6 message options */ |
| 380 | unsigned char *option = NULL; |
| 381 | /* 8-bit identifier of the type of ICMPv6 option */ |
| 382 | unsigned char type = 0; |
| 383 | struct icmp6_ra_prefix_info *prefix = NULL; |
| 384 | |
Ehsan Mohandesi | a29df56 | 2023-05-18 11:24:38 -0700 | [diff] [blame^] | 385 | if (len > ETH_MAX_MTU) |
| 386 | return -EMSGSIZE; |
Ehsan Mohandesi | 6de98b6 | 2023-04-21 17:08:21 -0700 | [diff] [blame] | 387 | /* Ignore the packet if router lifetime is 0. */ |
| 388 | if (!icmp->icmp6_rt_lifetime) |
| 389 | return -EOPNOTSUPP; |
| 390 | |
| 391 | /* Processing the options */ |
| 392 | option = msg->opt; |
| 393 | while (remaining_option_len > 0) { |
| 394 | /* The 2nd byte of the option is its length. */ |
| 395 | option_len = option[1]; |
| 396 | /* All included options should have a positive length. */ |
| 397 | if (option_len == 0) |
| 398 | return -EINVAL; |
| 399 | |
| 400 | type = option[0]; |
| 401 | /* All option types except Prefix Information are ignored. */ |
| 402 | switch (type) { |
| 403 | case ND_OPT_SOURCE_LL_ADDR: |
| 404 | case ND_OPT_TARGET_LL_ADDR: |
| 405 | case ND_OPT_REDIRECT_HDR: |
| 406 | case ND_OPT_MTU: |
| 407 | break; |
| 408 | case ND_OPT_PREFIX_INFO: |
| 409 | prefix = (struct icmp6_ra_prefix_info *)option; |
| 410 | /* The link-local prefix 0xfe80::/10 is ignored. */ |
| 411 | if ((ntohs(prefix->prefix.s6_addr16[0]) & |
| 412 | IPV6_LINK_LOCAL_MASK) == IPV6_LINK_LOCAL_PREFIX) |
| 413 | break; |
| 414 | if (prefix->on_link && ntohl(prefix->valid_lifetime)) { |
| 415 | net_prefix_length = prefix->prefix_len; |
| 416 | net_gateway6 = ip6->saddr; |
| 417 | return 0; |
| 418 | } |
| 419 | break; |
| 420 | default: |
| 421 | debug("Unknown IPv6 Neighbor Discovery Option 0x%x\n", |
| 422 | type); |
| 423 | } |
| 424 | |
| 425 | option_len <<= 3; /* Option length is a multiple of 8. */ |
| 426 | remaining_option_len -= option_len; |
| 427 | option += option_len; |
| 428 | } |
| 429 | |
| 430 | return -EADDRNOTAVAIL; |
| 431 | } |
| 432 | |
Viacheslav Mitrofanov | c6610e1 | 2022-12-02 12:18:01 +0300 | [diff] [blame] | 433 | int ndisc_receive(struct ethernet_hdr *et, struct ip6_hdr *ip6, int len) |
| 434 | { |
| 435 | struct icmp6hdr *icmp = |
| 436 | (struct icmp6hdr *)(((uchar *)ip6) + IP6_HDR_SIZE); |
| 437 | struct nd_msg *ndisc = (struct nd_msg *)icmp; |
| 438 | uchar neigh_eth_addr[6]; |
Ehsan Mohandesi | 6de98b6 | 2023-04-21 17:08:21 -0700 | [diff] [blame] | 439 | int err = 0; // The error code returned calling functions. |
Viacheslav Mitrofanov | c6610e1 | 2022-12-02 12:18:01 +0300 | [diff] [blame] | 440 | |
| 441 | switch (icmp->icmp6_type) { |
| 442 | case IPV6_NDISC_NEIGHBOUR_SOLICITATION: |
| 443 | debug("received neighbor solicitation for %pI6c from %pI6c\n", |
| 444 | &ndisc->target, &ip6->saddr); |
| 445 | if (ip6_is_our_addr(&ndisc->target) && |
| 446 | ndisc_has_option(ip6, ND_OPT_SOURCE_LL_ADDR)) { |
| 447 | ndisc_extract_enetaddr(ndisc, neigh_eth_addr); |
| 448 | ip6_send_na(neigh_eth_addr, &ip6->saddr, |
| 449 | &ndisc->target); |
| 450 | } |
| 451 | break; |
| 452 | |
| 453 | case IPV6_NDISC_NEIGHBOUR_ADVERTISEMENT: |
| 454 | /* are we waiting for a reply ? */ |
| 455 | if (ip6_is_unspecified_addr(&net_nd_sol_packet_ip6)) |
| 456 | break; |
| 457 | |
| 458 | if ((memcmp(&ndisc->target, &net_nd_rep_packet_ip6, |
| 459 | sizeof(struct in6_addr)) == 0) && |
| 460 | ndisc_has_option(ip6, ND_OPT_TARGET_LL_ADDR)) { |
| 461 | ndisc_extract_enetaddr(ndisc, neigh_eth_addr); |
| 462 | |
| 463 | /* save address for later use */ |
| 464 | if (!net_nd_packet_mac) |
Heinrich Schuchardt | 56e3b14 | 2022-12-07 11:53:29 +0100 | [diff] [blame] | 465 | net_nd_packet_mac = neigh_eth_addr; |
Viacheslav Mitrofanov | c6610e1 | 2022-12-02 12:18:01 +0300 | [diff] [blame] | 466 | |
| 467 | /* modify header, and transmit it */ |
| 468 | memcpy(((struct ethernet_hdr *)net_nd_tx_packet)->et_dest, |
| 469 | neigh_eth_addr, 6); |
| 470 | |
| 471 | net_send_packet(net_nd_tx_packet, |
| 472 | net_nd_tx_packet_size); |
| 473 | |
| 474 | /* no ND request pending now */ |
| 475 | net_nd_sol_packet_ip6 = net_null_addr_ip6; |
| 476 | net_nd_tx_packet_size = 0; |
| 477 | net_nd_packet_mac = NULL; |
| 478 | } |
| 479 | break; |
Ehsan Mohandesi | 6de98b6 | 2023-04-21 17:08:21 -0700 | [diff] [blame] | 480 | case IPV6_NDISC_ROUTER_SOLICITATION: |
| 481 | break; |
| 482 | case IPV6_NDISC_ROUTER_ADVERTISEMENT: |
| 483 | debug("Received router advertisement for %pI6c from %pI6c\n", |
| 484 | &ip6->daddr, &ip6->saddr); |
| 485 | /* |
| 486 | * If gateway and prefix are set, the RA packet is ignored. The |
| 487 | * reason is that the U-Boot code is supposed to be as compact |
| 488 | * as possible and does not need to take care of multiple |
| 489 | * routers. In addition to that, U-Boot does not want to handle |
| 490 | * scenarios like a router setting its lifetime to zero to |
| 491 | * indicate it is not routing anymore. U-Boot program has a |
| 492 | * short life when the system boots up and does not need such |
| 493 | * sophistication. |
| 494 | */ |
| 495 | if (!ip6_is_unspecified_addr(&net_gateway6) && |
| 496 | net_prefix_length != 0) { |
| 497 | break; |
| 498 | } |
| 499 | if (!validate_ra(ip6)) { |
| 500 | debug("Invalid router advertisement message.\n"); |
| 501 | break; |
| 502 | } |
| 503 | err = process_ra(ip6, len); |
| 504 | if (err) |
| 505 | debug("Ignored router advertisement. Error: %d\n", err); |
| 506 | else |
| 507 | printf("Set gatewayip6: %pI6c, prefix_length: %d\n", |
| 508 | &net_gateway6, net_prefix_length); |
| 509 | break; |
Viacheslav Mitrofanov | c6610e1 | 2022-12-02 12:18:01 +0300 | [diff] [blame] | 510 | default: |
| 511 | debug("Unexpected ICMPv6 type 0x%x\n", icmp->icmp6_type); |
| 512 | return -1; |
| 513 | } |
| 514 | |
| 515 | return 0; |
| 516 | } |