ip.c revision 329423
1318320Stsoome/* 2318320Stsoome * Copyright (c) 1992 Regents of the University of California. 3318320Stsoome * All rights reserved. 4318320Stsoome * 5318320Stsoome * This software was developed by the Computer Systems Engineering group 6318320Stsoome * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 7318320Stsoome * contributed to Berkeley. 8318320Stsoome * 9318320Stsoome * Redistribution and use in source and binary forms, with or without 10318320Stsoome * modification, are permitted provided that the following conditions 11318320Stsoome * are met: 12318320Stsoome * 1. Redistributions of source code must retain the above copyright 13318320Stsoome * notice, this list of conditions and the following disclaimer. 14318320Stsoome * 2. Redistributions in binary form must reproduce the above copyright 15318320Stsoome * notice, this list of conditions and the following disclaimer in the 16318320Stsoome * documentation and/or other materials provided with the distribution. 17318320Stsoome * 3. Neither the name of the University nor the names of its contributors 18318320Stsoome * may be used to endorse or promote products derived from this software 19318320Stsoome * without specific prior written permission. 20318320Stsoome * 21318320Stsoome * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22318320Stsoome * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23318320Stsoome * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24318320Stsoome * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25318320Stsoome * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26318320Stsoome * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27318320Stsoome * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28318320Stsoome * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29318320Stsoome * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30318320Stsoome * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31318320Stsoome * SUCH DAMAGE. 32318320Stsoome */ 33318320Stsoome 34318320Stsoome/* 35318320Stsoome * The send and receive functions were originally implemented in udp.c and 36318320Stsoome * moved here. Also it is likely some more cleanup can be done, especially 37318320Stsoome * once we will implement the support for tcp. 38318320Stsoome */ 39318320Stsoome 40318320Stsoome#include <sys/cdefs.h> 41318320Stsoome__FBSDID("$FreeBSD: stable/11/stand/libsa/ip.c 329423 2018-02-17 02:14:01Z kevans $"); 42318320Stsoome 43318320Stsoome#include <sys/param.h> 44318320Stsoome#include <sys/socket.h> 45318320Stsoome#include <sys/queue.h> 46318320Stsoome 47318320Stsoome#include <string.h> 48318320Stsoome 49318320Stsoome#include <net/if.h> 50318320Stsoome#include <netinet/in.h> 51318320Stsoome#include <netinet/if_ether.h> 52318320Stsoome#include <netinet/in_systm.h> 53318320Stsoome 54318320Stsoome#include <netinet/in_pcb.h> 55318320Stsoome#include <netinet/ip.h> 56318320Stsoome#include <netinet/ip_var.h> 57318320Stsoome#include <netinet/udp.h> 58318320Stsoome#include <netinet/udp_var.h> 59318320Stsoome 60318320Stsoome#include "stand.h" 61318320Stsoome#include "net.h" 62318320Stsoome 63318320Stsoometypedef STAILQ_HEAD(ipqueue, ip_queue) ip_queue_t; 64318320Stsoomestruct ip_queue { 65318320Stsoome void *ipq_pkt; 66318320Stsoome struct ip *ipq_hdr; 67318320Stsoome STAILQ_ENTRY(ip_queue) ipq_next; 68318320Stsoome}; 69318320Stsoome 70318320Stsoome/* 71318320Stsoome * Fragment re-assembly queue. 72318320Stsoome */ 73318320Stsoomestruct ip_reasm { 74318320Stsoome struct in_addr ip_src; 75318320Stsoome struct in_addr ip_dst; 76318320Stsoome uint16_t ip_id; 77318320Stsoome uint8_t ip_proto; 78318320Stsoome uint8_t ip_ttl; 79318320Stsoome size_t ip_total_size; 80318320Stsoome ip_queue_t ip_queue; 81318320Stsoome void *ip_pkt; 82318320Stsoome struct ip *ip_hdr; 83318320Stsoome STAILQ_ENTRY(ip_reasm) ip_next; 84318320Stsoome}; 85318320Stsoome 86318320StsoomeSTAILQ_HEAD(ire_list, ip_reasm) ire_list = STAILQ_HEAD_INITIALIZER(ire_list); 87318320Stsoome 88318320Stsoome/* Caller must leave room for ethernet and ip headers in front!! */ 89318320Stsoomessize_t 90318320Stsoomesendip(struct iodesc *d, void *pkt, size_t len, uint8_t proto) 91318320Stsoome{ 92318320Stsoome ssize_t cc; 93318320Stsoome struct ip *ip; 94318320Stsoome u_char *ea; 95318320Stsoome 96318320Stsoome#ifdef NET_DEBUG 97318320Stsoome if (debug) { 98318320Stsoome printf("sendip: proto: %x d=%p called.\n", proto, (void *)d); 99318320Stsoome if (d) { 100318320Stsoome printf("saddr: %s:%d", 101318320Stsoome inet_ntoa(d->myip), ntohs(d->myport)); 102318320Stsoome printf(" daddr: %s:%d\n", 103318320Stsoome inet_ntoa(d->destip), ntohs(d->destport)); 104318320Stsoome } 105318320Stsoome } 106318320Stsoome#endif 107318320Stsoome 108318320Stsoome ip = (struct ip *)pkt - 1; 109318320Stsoome len += sizeof(*ip); 110318320Stsoome 111318320Stsoome bzero(ip, sizeof(*ip)); 112318320Stsoome 113318320Stsoome ip->ip_v = IPVERSION; /* half-char */ 114318320Stsoome ip->ip_hl = sizeof(*ip) >> 2; /* half-char */ 115318320Stsoome ip->ip_len = htons(len); 116318320Stsoome ip->ip_p = proto; /* char */ 117318320Stsoome ip->ip_ttl = IPDEFTTL; /* char */ 118318320Stsoome ip->ip_src = d->myip; 119318320Stsoome ip->ip_dst = d->destip; 120318320Stsoome ip->ip_sum = in_cksum(ip, sizeof(*ip)); /* short, but special */ 121318320Stsoome 122318320Stsoome if (ip->ip_dst.s_addr == INADDR_BROADCAST || ip->ip_src.s_addr == 0 || 123318320Stsoome netmask == 0 || SAMENET(ip->ip_src, ip->ip_dst, netmask)) 124318320Stsoome ea = arpwhohas(d, ip->ip_dst); 125318320Stsoome else 126318320Stsoome ea = arpwhohas(d, gateip); 127318320Stsoome 128318320Stsoome cc = sendether(d, ip, len, ea, ETHERTYPE_IP); 129318320Stsoome if (cc == -1) 130318320Stsoome return (-1); 131318320Stsoome if (cc != len) 132318320Stsoome panic("sendip: bad write (%zd != %zd)", cc, len); 133318320Stsoome return (cc - sizeof(*ip)); 134318320Stsoome} 135318320Stsoome 136318320Stsoomestatic void 137318320Stsoomeip_reasm_free(struct ip_reasm *ipr) 138318320Stsoome{ 139318320Stsoome struct ip_queue *ipq; 140318320Stsoome 141318320Stsoome while ((ipq = STAILQ_FIRST(&ipr->ip_queue)) != NULL) { 142318320Stsoome STAILQ_REMOVE_HEAD(&ipr->ip_queue, ipq_next); 143318320Stsoome free(ipq->ipq_pkt); 144318320Stsoome free(ipq); 145318320Stsoome } 146318320Stsoome free(ipr->ip_pkt); 147318320Stsoome free(ipr); 148318320Stsoome} 149318320Stsoome 150318320Stsoomestatic int 151318320Stsoomeip_reasm_add(struct ip_reasm *ipr, void *pkt, struct ip *ip) 152318320Stsoome{ 153318320Stsoome struct ip_queue *ipq, *prev, *p; 154318320Stsoome 155318320Stsoome if ((ipq = calloc(1, sizeof (*ipq))) == NULL) 156318320Stsoome return (1); 157318320Stsoome 158318320Stsoome ipq->ipq_pkt = pkt; 159318320Stsoome ipq->ipq_hdr = ip; 160318320Stsoome 161318320Stsoome prev = NULL; 162318320Stsoome STAILQ_FOREACH(p, &ipr->ip_queue, ipq_next) { 163318320Stsoome if ((ntohs(p->ipq_hdr->ip_off) & IP_OFFMASK) < 164318320Stsoome (ntohs(ip->ip_off) & IP_OFFMASK)) { 165318320Stsoome prev = p; 166318320Stsoome continue; 167318320Stsoome } 168318320Stsoome if (prev == NULL) 169318320Stsoome break; 170318320Stsoome 171318320Stsoome STAILQ_INSERT_AFTER(&ipr->ip_queue, prev, ipq, ipq_next); 172318320Stsoome return (0); 173318320Stsoome } 174318320Stsoome STAILQ_INSERT_HEAD(&ipr->ip_queue, ipq, ipq_next); 175318320Stsoome return (0); 176318320Stsoome} 177318320Stsoome 178318320Stsoome/* 179318320Stsoome * Receive a IP packet and validate it is for us. 180318320Stsoome */ 181318320Stsoomestatic ssize_t 182318320Stsoomereadipv4(struct iodesc *d, void **pkt, void **payload, time_t tleft, 183318320Stsoome uint8_t proto) 184318320Stsoome{ 185318320Stsoome ssize_t n; 186318320Stsoome size_t hlen; 187318320Stsoome struct ether_header *eh; 188318320Stsoome struct ip *ip; 189318320Stsoome struct udphdr *uh; 190318320Stsoome uint16_t etype; /* host order */ 191318320Stsoome char *ptr; 192318320Stsoome struct ip_reasm *ipr; 193318320Stsoome struct ip_queue *ipq, *last; 194318320Stsoome 195318320Stsoome#ifdef NET_DEBUG 196318320Stsoome if (debug) 197318320Stsoome printf("readip: called\n"); 198318320Stsoome#endif 199318320Stsoome 200318320Stsoome ip = NULL; 201318320Stsoome ptr = NULL; 202318320Stsoome n = readether(d, (void **)&ptr, (void **)&ip, tleft, &etype); 203318320Stsoome if (n == -1 || n < sizeof(*ip) + sizeof(*uh)) { 204318320Stsoome free(ptr); 205318320Stsoome return (-1); 206318320Stsoome } 207318320Stsoome 208318320Stsoome /* Ethernet address checks now in readether() */ 209318320Stsoome 210318320Stsoome /* Need to respond to ARP requests. */ 211318320Stsoome if (etype == ETHERTYPE_ARP) { 212318320Stsoome struct arphdr *ah = (void *)ip; 213318320Stsoome if (ah->ar_op == htons(ARPOP_REQUEST)) { 214318320Stsoome /* Send ARP reply */ 215318320Stsoome arp_reply(d, ah); 216318320Stsoome } 217318320Stsoome free(ptr); 218318320Stsoome errno = EAGAIN; /* Call me again. */ 219318320Stsoome return (-1); 220318320Stsoome } 221318320Stsoome 222318320Stsoome if (etype != ETHERTYPE_IP) { 223318320Stsoome#ifdef NET_DEBUG 224318320Stsoome if (debug) 225318320Stsoome printf("readip: not IP. ether_type=%x\n", etype); 226318320Stsoome#endif 227318320Stsoome free(ptr); 228318320Stsoome return (-1); 229318320Stsoome } 230318320Stsoome 231318320Stsoome /* Check ip header */ 232329140Skevans if (ip->ip_v != IPVERSION || /* half char */ 233329140Skevans ip->ip_p != proto) { 234318320Stsoome#ifdef NET_DEBUG 235318320Stsoome if (debug) { 236318320Stsoome printf("readip: IP version or proto. ip_v=%d ip_p=%d\n", 237318320Stsoome ip->ip_v, ip->ip_p); 238318320Stsoome } 239318320Stsoome#endif 240318320Stsoome free(ptr); 241318320Stsoome return (-1); 242318320Stsoome } 243318320Stsoome 244318320Stsoome hlen = ip->ip_hl << 2; 245318320Stsoome if (hlen < sizeof(*ip) || 246318320Stsoome in_cksum(ip, hlen) != 0) { 247318320Stsoome#ifdef NET_DEBUG 248318320Stsoome if (debug) 249318320Stsoome printf("readip: short hdr or bad cksum.\n"); 250318320Stsoome#endif 251318320Stsoome free(ptr); 252318320Stsoome return (-1); 253318320Stsoome } 254318320Stsoome if (n < ntohs(ip->ip_len)) { 255318320Stsoome#ifdef NET_DEBUG 256318320Stsoome if (debug) 257318320Stsoome printf("readip: bad length %d < %d.\n", 258318320Stsoome (int)n, ntohs(ip->ip_len)); 259318320Stsoome#endif 260318320Stsoome free(ptr); 261318320Stsoome return (-1); 262318320Stsoome } 263318320Stsoome if (d->myip.s_addr && ip->ip_dst.s_addr != d->myip.s_addr) { 264318320Stsoome#ifdef NET_DEBUG 265318320Stsoome if (debug) { 266318320Stsoome printf("readip: bad saddr %s != ", inet_ntoa(d->myip)); 267318320Stsoome printf("%s\n", inet_ntoa(ip->ip_dst)); 268318320Stsoome } 269318320Stsoome#endif 270318320Stsoome free(ptr); 271318320Stsoome return (-1); 272318320Stsoome } 273318320Stsoome 274318320Stsoome /* Unfragmented packet. */ 275318320Stsoome if ((ntohs(ip->ip_off) & IP_MF) == 0 && 276318320Stsoome (ntohs(ip->ip_off) & IP_OFFMASK) == 0) { 277318320Stsoome uh = (struct udphdr *)((uintptr_t)ip + sizeof (*ip)); 278318320Stsoome /* If there were ip options, make them go away */ 279318320Stsoome if (hlen != sizeof(*ip)) { 280318320Stsoome bcopy(((u_char *)ip) + hlen, uh, uh->uh_ulen - hlen); 281318320Stsoome ip->ip_len = htons(sizeof(*ip)); 282318320Stsoome n -= hlen - sizeof(*ip); 283318320Stsoome } 284318320Stsoome 285318320Stsoome n = (n > (ntohs(ip->ip_len) - sizeof(*ip))) ? 286318320Stsoome ntohs(ip->ip_len) - sizeof(*ip) : n; 287318320Stsoome *pkt = ptr; 288318320Stsoome *payload = (void *)((uintptr_t)ip + sizeof(*ip)); 289318320Stsoome return (n); 290318320Stsoome } 291318320Stsoome 292318320Stsoome STAILQ_FOREACH(ipr, &ire_list, ip_next) { 293318320Stsoome if (ipr->ip_src.s_addr == ip->ip_src.s_addr && 294318320Stsoome ipr->ip_dst.s_addr == ip->ip_dst.s_addr && 295318320Stsoome ipr->ip_id == ip->ip_id && 296318320Stsoome ipr->ip_proto == ip->ip_p) 297318320Stsoome break; 298318320Stsoome } 299318320Stsoome 300318320Stsoome /* Allocate new reassembly entry */ 301318320Stsoome if (ipr == NULL) { 302318320Stsoome if ((ipr = calloc(1, sizeof (*ipr))) == NULL) { 303318320Stsoome free(ptr); 304318320Stsoome return (-1); 305318320Stsoome } 306318320Stsoome 307318320Stsoome ipr->ip_src = ip->ip_src; 308318320Stsoome ipr->ip_dst = ip->ip_dst; 309318320Stsoome ipr->ip_id = ip->ip_id; 310318320Stsoome ipr->ip_proto = ip->ip_p; 311318320Stsoome ipr->ip_ttl = MAXTTL; 312318320Stsoome STAILQ_INIT(&ipr->ip_queue); 313318320Stsoome STAILQ_INSERT_TAIL(&ire_list, ipr, ip_next); 314318320Stsoome } 315318320Stsoome 316318320Stsoome if (ip_reasm_add(ipr, ptr, ip) != 0) { 317318320Stsoome STAILQ_REMOVE(&ire_list, ipr, ip_reasm, ip_next); 318318320Stsoome free(ipr); 319318320Stsoome free(ptr); 320318320Stsoome return (-1); 321318320Stsoome } 322318320Stsoome 323318320Stsoome if ((ntohs(ip->ip_off) & IP_MF) == 0) { 324318320Stsoome ipr->ip_total_size = (8 * (ntohs(ip->ip_off) & IP_OFFMASK)); 325318320Stsoome ipr->ip_total_size += n + sizeof (*ip); 326318320Stsoome ipr->ip_total_size += sizeof (struct ether_header); 327318320Stsoome 328318320Stsoome ipr->ip_pkt = malloc(ipr->ip_total_size + 2); 329318320Stsoome if (ipr->ip_pkt == NULL) { 330318320Stsoome STAILQ_REMOVE(&ire_list, ipr, ip_reasm, ip_next); 331318320Stsoome ip_reasm_free(ipr); 332318320Stsoome return (-1); 333318320Stsoome } 334318320Stsoome } 335318320Stsoome 336318320Stsoome /* 337318320Stsoome * If we do not have re-assembly buffer ipr->ip_pkt, we are still 338318320Stsoome * missing fragments, so just restart the read. 339318320Stsoome */ 340318320Stsoome if (ipr->ip_pkt == NULL) { 341318320Stsoome errno = EAGAIN; 342318320Stsoome return (-1); 343318320Stsoome } 344318320Stsoome 345318320Stsoome /* 346318320Stsoome * Walk the packet list in reassembly queue, if we got all the 347318320Stsoome * fragments, build the packet. 348318320Stsoome */ 349318320Stsoome n = 0; 350318320Stsoome last = NULL; 351318320Stsoome STAILQ_FOREACH(ipq, &ipr->ip_queue, ipq_next) { 352318320Stsoome if ((ntohs(ipq->ipq_hdr->ip_off) & IP_OFFMASK) != n / 8) { 353329140Skevans STAILQ_REMOVE(&ire_list, ipr, ip_reasm, ip_next); 354329140Skevans ip_reasm_free(ipr); 355318320Stsoome return (-1); 356318320Stsoome } 357318320Stsoome 358318320Stsoome n += ntohs(ipq->ipq_hdr->ip_len) - (ipq->ipq_hdr->ip_hl << 2); 359318320Stsoome last = ipq; 360318320Stsoome } 361318320Stsoome if ((ntohs(last->ipq_hdr->ip_off) & IP_MF) != 0) { 362318320Stsoome errno = EAGAIN; 363318320Stsoome return (-1); 364318320Stsoome } 365318320Stsoome 366318320Stsoome ipq = STAILQ_FIRST(&ipr->ip_queue); 367318320Stsoome /* Fabricate ethernet header */ 368318320Stsoome eh = (struct ether_header *)((uintptr_t)ipr->ip_pkt + 2); 369318320Stsoome bcopy((void *)((uintptr_t)ipq->ipq_pkt + 2), eh, sizeof (*eh)); 370318320Stsoome 371318320Stsoome /* Fabricate IP header */ 372318320Stsoome ipr->ip_hdr = (struct ip *)((uintptr_t)eh + sizeof (*eh)); 373318320Stsoome bcopy(ipq->ipq_hdr, ipr->ip_hdr, sizeof (*ipr->ip_hdr)); 374318320Stsoome ipr->ip_hdr->ip_hl = sizeof (*ipr->ip_hdr) >> 2; 375318320Stsoome ipr->ip_hdr->ip_len = htons(n); 376318320Stsoome ipr->ip_hdr->ip_sum = 0; 377318320Stsoome ipr->ip_hdr->ip_sum = in_cksum(ipr->ip_hdr, sizeof (*ipr->ip_hdr)); 378318320Stsoome 379318320Stsoome n = 0; 380318320Stsoome ptr = (char *)((uintptr_t)ipr->ip_hdr + sizeof (*ipr->ip_hdr)); 381318320Stsoome STAILQ_FOREACH(ipq, &ipr->ip_queue, ipq_next) { 382318320Stsoome char *data; 383318320Stsoome size_t len; 384318320Stsoome 385318320Stsoome hlen = ipq->ipq_hdr->ip_hl << 2; 386318320Stsoome len = ntohs(ipq->ipq_hdr->ip_len) - hlen; 387318320Stsoome data = (char *)((uintptr_t)ipq->ipq_hdr + hlen); 388318320Stsoome 389318320Stsoome bcopy(data, ptr + n, len); 390318320Stsoome n += len; 391318320Stsoome } 392318320Stsoome 393318320Stsoome *pkt = ipr->ip_pkt; 394318320Stsoome ipr->ip_pkt = NULL; /* Avoid free from ip_reasm_free() */ 395318320Stsoome *payload = ptr; 396318320Stsoome 397318320Stsoome /* Clean up the reassembly list */ 398318320Stsoome while ((ipr = STAILQ_FIRST(&ire_list)) != NULL) { 399318320Stsoome STAILQ_REMOVE_HEAD(&ire_list, ip_next); 400318320Stsoome ip_reasm_free(ipr); 401318320Stsoome } 402318320Stsoome return (n); 403318320Stsoome} 404318320Stsoome 405318320Stsoome/* 406318320Stsoome * Receive a IP packet. 407318320Stsoome */ 408318320Stsoomessize_t 409318320Stsoomereadip(struct iodesc *d, void **pkt, void **payload, time_t tleft, 410318320Stsoome uint8_t proto) 411318320Stsoome{ 412318320Stsoome time_t t; 413318320Stsoome ssize_t ret = -1; 414318320Stsoome 415318320Stsoome t = getsecs(); 416318320Stsoome while ((getsecs() - t) < tleft) { 417318320Stsoome errno = 0; 418318320Stsoome ret = readipv4(d, pkt, payload, tleft, proto); 419329423Skevans if (ret >= 0) 420329423Skevans return (ret); 421329423Skevans /* Bubble up the error if it wasn't successful */ 422318320Stsoome if (errno != EAGAIN) 423329423Skevans return (-1); 424318320Stsoome } 425329423Skevans /* We've exhausted tleft; timeout */ 426329423Skevans errno = ETIMEDOUT; 427329423Skevans return (-1); 428318320Stsoome} 429