diff options
Diffstat (limited to 'contrib/ipfilter/ipsend/ip.c')
-rw-r--r-- | contrib/ipfilter/ipsend/ip.c | 346 |
1 files changed, 346 insertions, 0 deletions
diff --git a/contrib/ipfilter/ipsend/ip.c b/contrib/ipfilter/ipsend/ip.c new file mode 100644 index 0000000..2c7f7ff --- /dev/null +++ b/contrib/ipfilter/ipsend/ip.c @@ -0,0 +1,346 @@ +/* + * ip.c (C) 1995 Darren Reed + * + * The author provides this program as-is, with no gaurantee for its + * suitability for any specific purpose. The author takes no responsibility + * for the misuse/abuse of this program and provides it for the sole purpose + * of testing packet filter policies. This file maybe distributed freely + * providing it is not modified and that this notice remains in tact. + */ +#if !defined(lint) && defined(LIBC_SCCS) +static char sccsid[] = "%W% %G% (C)1995"; +#endif +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <string.h> +#include <sys/types.h> +#include <netinet/in_systm.h> +#include <sys/socket.h> +#include <net/if.h> +#include <netinet/in.h> +#include <netinet/ip.h> +#include <netinet/tcp.h> +#include <netinet/udp.h> +#include <netinet/ip_icmp.h> +#ifndef linux +#include <netinet/if_ether.h> +#include <netinet/ip_var.h> +#include <netinet/tcpip.h> +#endif +#include "ip_compat.h" +#ifdef linux +#include "tcpip.h" +#endif + + +static char *ipbuf = NULL, *ethbuf = NULL; + +extern int arp(), sendip(); + +u_short chksum(buf,len) +u_short *buf; +int len; +{ + u_long sum = 0; + int nwords = len >> 1; + + for(; nwords > 0; nwords--) + sum += *buf++; + sum = (sum>>16) + (sum & 0xffff); + sum += (sum >>16); + return (~sum); +} + + +int send_ether(nfd, buf, len, gwip) +int nfd, len; +char *buf; +struct in_addr gwip; +{ + static struct in_addr last_gw; + static char last_arp[6] = { 0, 0, 0, 0, 0, 0}; + ether_header_t *eh; + char *s; + int err; + + if (!ethbuf) + ethbuf = (char *)calloc(1, 65536+1024); + s = ethbuf; + eh = (ether_header_t *)s; + + bcopy((char *)buf, s + sizeof(*eh), len); + if (gwip.s_addr == last_gw.s_addr) + bcopy(last_arp, (char *)&eh->ether_dhost, 6); + else if (arp((char *)&gwip, &eh->ether_dhost) == -1) + { + perror("arp"); + return -2; + } + eh->ether_type = ETHERTYPE_IP; + last_gw.s_addr = gwip.s_addr; + err = sendip(nfd, s, sizeof(*eh) + len); + return err; +} + + +/* + */ +int send_ip(nfd, mtu, ip, gwip, frag) +int nfd, mtu; +ip_t *ip; +struct in_addr gwip; +int frag; +{ + static struct in_addr last_gw; + static char last_arp[6] = { 0, 0, 0, 0, 0, 0}; + static u_short id = 0; + ether_header_t *eh; + ip_t ipsv; + int err; + + if (!ipbuf) + ipbuf = (char *)malloc(65536); + eh = (ether_header_t *)ipbuf; + + bzero((char *)&eh->ether_shost, sizeof(eh->ether_shost)); + if (last_gw.s_addr && (gwip.s_addr == last_gw.s_addr)) + bcopy(last_arp, (char *)&eh->ether_dhost, 6); + else if (arp((char *)&gwip, &eh->ether_dhost) == -1) + { + perror("arp"); + return -2; + } + bcopy((char *)&eh->ether_dhost, last_arp, sizeof(last_arp)); + eh->ether_type = ETHERTYPE_IP; + + bcopy((char *)ip, (char *)&ipsv, sizeof(*ip)); + last_gw.s_addr = gwip.s_addr; + ip->ip_len = htons(ip->ip_len); + ip->ip_off = htons(ip->ip_off); + if (!ip->ip_v) + ip->ip_v = IPVERSION; + if (!ip->ip_id) + ip->ip_id = htons(id++); + if (!ip->ip_ttl) + ip->ip_ttl = 60; + + if (!frag || (sizeof(*eh) + ntohs(ip->ip_len) < mtu)) + { + ip->ip_sum = 0; + ip->ip_sum = chksum(ip, ip->ip_hl << 2); + + bcopy((char *)ip, ipbuf + sizeof(*eh), ntohs(ip->ip_len)); + err = sendip(nfd, ipbuf, sizeof(*eh) + ntohs(ip->ip_len)); + } + else + { + /* + * Actually, this is bogus because we're putting all IP + * options in every packet, which isn't always what should be + * done. Will do for now. + */ + ether_header_t eth; + char optcpy[48], ol; + char *s; + int i, iplen, sent = 0, ts, hlen, olen; + + hlen = ip->ip_hl << 2; + if (mtu < (hlen + 8)) { + fprintf(stderr, "mtu (%d) < ip header size (%d) + 8\n", + mtu, hlen); + fprintf(stderr, "can't fragment data\n"); + return -2; + } + ol = (ip->ip_hl << 2) - sizeof(*ip); + for (i = 0, s = (char*)(ip + 1); ol > 0; ) + if (*s == IPOPT_EOL) { + optcpy[i++] = *s; + break; + } else if (*s == IPOPT_NOP) { + s++; + ol--; + } else + { + olen = (int)(*(u_char *)(s + 1)); + ol -= olen; + if (IPOPT_COPIED(*s)) + { + bcopy(s, optcpy + i, olen); + i += olen; + s += olen; + } + } + if (i) + { + /* + * pad out + */ + while ((i & 3) && (i & 3) != 3) + optcpy[i++] = IPOPT_NOP; + if ((i & 3) == 3) + optcpy[i++] = IPOPT_EOL; + } + + bcopy((char *)eh, (char *)ð, sizeof(eth)); + s = (char *)ip + hlen; + iplen = ntohs(ip->ip_len) - hlen; + ip->ip_off |= htons(IP_MF); + + while (1) + { + if ((sent + (mtu - hlen)) >= iplen) + { + ip->ip_off ^= htons(IP_MF); + ts = iplen - sent; + } + else + ts = (mtu - hlen); + ip->ip_off &= htons(0xe000); + ip->ip_off |= htons(sent >> 3); + ts += hlen; + ip->ip_len = htons(ts); + ip->ip_sum = 0; + ip->ip_sum = chksum(ip, hlen); + bcopy((char *)ip, ipbuf + sizeof(*eh), hlen); + bcopy(s + sent, ipbuf + sizeof(*eh) + hlen, ts - hlen); + err = sendip(nfd, ipbuf, sizeof(*eh) + ts); + + bcopy((char *)ð, ipbuf, sizeof(eth)); + sent += (ts - hlen); + if (!(ntohs(ip->ip_off) & IP_MF)) + break; + else if (!(ip->ip_off & htons(0x1fff))) + { + hlen = i + sizeof(*ip); + ip->ip_hl = (sizeof(*ip) + i) >> 2; + bcopy(optcpy, (char *)(ip + 1), i); + } + } + } + + bcopy((char *)&ipsv, (char *)ip, sizeof(*ip)); + return err; +} + + +/* + * send a tcp packet. + */ +int send_tcp(nfd, mtu, ip, gwip) +int nfd, mtu; +ip_t *ip; +struct in_addr gwip; +{ + static tcp_seq iss = 2; + struct tcpiphdr *ti; + int thlen, i; + u_long lbuf[20]; + + ti = (struct tcpiphdr *)lbuf; + bzero((char *)ti, sizeof(*ti)); + thlen = sizeof(tcphdr_t); + ip->ip_p = IPPROTO_TCP; + ti->ti_pr = ip->ip_p; + ti->ti_src = ip->ip_src; + ti->ti_dst = ip->ip_dst; + bcopy((char *)ip + (ip->ip_hl << 2), + (char *)&ti->ti_sport, sizeof(tcphdr_t)); + + if (!ti->ti_win) + ti->ti_win = htons(4096); + if (!ti->ti_seq) + ti->ti_seq = htonl(iss); + iss += 64; + + if ((ti->ti_flags == TH_SYN) && !ip->ip_off) + { + ip = (ip_t *)realloc((char *)ip, ntohs(ip->ip_len) + 4); + i = sizeof(struct tcpiphdr) / sizeof(long); + lbuf[i] = htonl(0x020405b4); + bcopy((char *)(lbuf + i), (char*)ip + ntohs(ip->ip_len), + sizeof(u_long)); + thlen += 4; + } + if (!ti->ti_off) + ti->ti_off = thlen >> 2; + ti->ti_len = htons(thlen); + ip->ip_len = (ip->ip_hl << 2) + thlen; + ti->ti_sum = 0; + ti->ti_sum = chksum(ti, thlen + sizeof(ip_t)); + + bcopy((char *)&ti->ti_sport, + (char *)ip + (ip->ip_hl << 2), thlen); + return send_ip(nfd, mtu, ip, gwip, 1); +} + + +/* + * send a udp packet. + */ +int send_udp(nfd, mtu, ip, gwip) +int nfd, mtu; +ip_t *ip; +struct in_addr gwip; +{ + struct tcpiphdr *ti; + int thlen; + u_long lbuf[20]; + + ti = (struct tcpiphdr *)lbuf; + bzero((char *)ti, sizeof(*ti)); + thlen = sizeof(udphdr_t); + ti->ti_pr = ip->ip_p; + ti->ti_src = ip->ip_src; + ti->ti_dst = ip->ip_dst; + bcopy((char *)ip + (ip->ip_hl << 2), + (char *)&ti->ti_sport, sizeof(udphdr_t)); + + ti->ti_len = htons(thlen); + ip->ip_len = (ip->ip_hl << 2) + thlen; + ti->ti_sum = 0; + ti->ti_sum = chksum(ti, thlen + sizeof(ip_t)); + + bcopy((char *)&ti->ti_sport, + (char *)ip + (ip->ip_hl << 2), sizeof(udphdr_t)); + return send_ip(nfd, mtu, ip, gwip, 1); +} + + +/* + * send an icmp packet. + */ +int send_icmp(nfd, mtu, ip, gwip) +int nfd, mtu; +ip_t *ip; +struct in_addr gwip; +{ + struct icmp *ic; + + ic = (struct icmp *)((char *)ip + (ip->ip_hl << 2)); + + ic->icmp_cksum = 0; + ic->icmp_cksum = chksum((char *)ic, sizeof(struct icmp)); + + return send_ip(nfd, mtu, ip, gwip, 1); +} + + +int send_packet(nfd, mtu, ip, gwip) +int nfd, mtu; +ip_t *ip; +struct in_addr gwip; +{ + switch (ip->ip_p) + { + case IPPROTO_TCP : + return send_tcp(nfd, mtu, ip, gwip); + case IPPROTO_UDP : + return send_udp(nfd, mtu, ip, gwip); + case IPPROTO_ICMP : + return send_icmp(nfd, mtu, ip, gwip); + default : + return send_ip(nfd, mtu, ip, gwip, 1); + } +} |