diff options
Diffstat (limited to 'lib/ipft_tx.c')
| -rw-r--r-- | lib/ipft_tx.c | 325 |
1 files changed, 325 insertions, 0 deletions
diff --git a/lib/ipft_tx.c b/lib/ipft_tx.c new file mode 100644 index 0000000..5dc65b4 --- /dev/null +++ b/lib/ipft_tx.c @@ -0,0 +1,325 @@ +/* + * Copyright (C) 2000-2006 by Darren Reed. + * + * See the IPFILTER.LICENCE file for details on licencing. + * + * $Id: ipft_tx.c,v 1.15.2.10 2007/09/03 21:54:44 darrenr Exp $ + */ +#if !defined(lint) +static const char sccsid[] = "@(#)ipft_tx.c 1.7 6/5/96 (C) 1993 Darren Reed"; +static const char rcsid[] = "@(#)$Id: ipft_tx.c,v 1.15.2.10 2007/09/03 21:54:44 darrenr Exp $"; +#endif + +#include <ctype.h> + +#include "ipf.h" +#include "ipt.h" + +#ifndef linux +#include <netinet/ip_var.h> +#endif +#include <netinet/tcpip.h> + + +extern int opts; + +static char *tx_proto = ""; + +static int text_open __P((char *)), text_close __P((void)); +static int text_readip __P((char *, int, char **, int *)); +static int parseline __P((char *, ip_t *, char **, int *)); + +static char myflagset[] = "FSRPAUEC"; +static u_char myflags[] = { TH_FIN, TH_SYN, TH_RST, TH_PUSH, + TH_ACK, TH_URG, TH_ECN, TH_CWR }; + +struct ipread iptext = { text_open, text_close, text_readip, R_DO_CKSUM }; +static FILE *tfp = NULL; +static int tfd = -1; + +static u_32_t tx_hostnum __P((char *, int *)); +static u_short tx_portnum __P((char *)); + + +/* + * returns an ip address as a long var as a result of either a DNS lookup or + * straight inet_addr() call + */ +static u_32_t tx_hostnum(host, resolved) +char *host; +int *resolved; +{ + u_32_t ipa; + + *resolved = 0; + if (!strcasecmp("any", host)) + return 0L; + if (ISDIGIT(*host)) + return inet_addr(host); + + if (gethost(host, &ipa) == -1) { + *resolved = -1; + fprintf(stderr, "can't resolve hostname: %s\n", host); + return 0; + } + return ipa; +} + + +/* + * find the port number given by the name, either from getservbyname() or + * straight atoi() + */ +static u_short tx_portnum(name) +char *name; +{ + struct servent *sp; + + if (ISDIGIT(*name)) + return (u_short)atoi(name); + sp = getservbyname(name, tx_proto); + if (sp) + return ntohs(sp->s_port); + (void) fprintf(stderr, "unknown service \"%s\".\n", name); + return 0; +} + + +char *tx_icmptypes[] = { + "echorep", (char *)NULL, (char *)NULL, "unreach", "squench", + "redir", (char *)NULL, (char *)NULL, "echo", "routerad", + "routersol", "timex", "paramprob", "timest", "timestrep", + "inforeq", "inforep", "maskreq", "maskrep", "END" +}; + +static int text_open(fname) +char *fname; +{ + if (tfp && tfd != -1) { + rewind(tfp); + return tfd; + } + + if (!strcmp(fname, "-")) { + tfd = 0; + tfp = stdin; + } else { + tfd = open(fname, O_RDONLY); + if (tfd != -1) + tfp = fdopen(tfd, "r"); + } + return tfd; +} + + +static int text_close() +{ + int cfd = tfd; + + tfd = -1; + return close(cfd); +} + + +static int text_readip(buf, cnt, ifn, dir) +char *buf, **ifn; +int cnt, *dir; +{ + register char *s; + char line[513]; + ip_t *ip; + + *ifn = NULL; + while (fgets(line, sizeof(line)-1, tfp)) { + if ((s = strchr(line, '\n'))) + *s = '\0'; + if ((s = strchr(line, '\r'))) + *s = '\0'; + if ((s = strchr(line, '#'))) + *s = '\0'; + if (!*line) + continue; + if ((opts & OPT_DEBUG) != 0) + printf("input: %s\n", line); + *ifn = NULL; + *dir = 0; + if (!parseline(line, (ip_t *)buf, ifn, dir)) { + ip = (ip_t *)buf; + return ntohs(ip->ip_len); + } + } + if (feof(tfp)) + return 0; + return -1; +} + +static int parseline(line, ip, ifn, out) +char *line; +ip_t *ip; +char **ifn; +int *out; +{ + tcphdr_t th, *tcp = &th; + struct icmp icmp, *ic = &icmp; + char *cps[20], **cpp, c, ipopts[68]; + int i, r; + + if (*ifn) + free(*ifn); + bzero((char *)ip, MAX(sizeof(*tcp), sizeof(*ic)) + sizeof(*ip)); + bzero((char *)tcp, sizeof(*tcp)); + bzero((char *)ic, sizeof(*ic)); + bzero(ipopts, sizeof(ipopts)); + IP_HL_A(ip, sizeof(*ip) >> 2); + IP_V_A(ip, IPVERSION); + for (i = 0, cps[0] = strtok(line, " \b\t\r\n"); cps[i] && i < 19; ) + cps[++i] = strtok(NULL, " \b\t\r\n"); + + cpp = cps; + if (!*cpp) + return 1; + + c = **cpp; + if (!ISALPHA(c) || (TOLOWER(c) != 'o' && TOLOWER(c) != 'i')) { + fprintf(stderr, "bad direction \"%s\"\n", *cpp); + return 1; + } + *out = (TOLOWER(c) == 'o') ? 1 : 0; + cpp++; + if (!*cpp) + return 1; + + if (!strcasecmp(*cpp, "on")) { + cpp++; + if (!*cpp) + return 1; + *ifn = strdup(*cpp++); + if (!*cpp) + return 1; + } + + c = **cpp; + ip->ip_len = sizeof(ip_t); + if (!strcasecmp(*cpp, "tcp") || !strcasecmp(*cpp, "udp") || + !strcasecmp(*cpp, "icmp")) { + if (c == 't') { + ip->ip_p = IPPROTO_TCP; + ip->ip_len += sizeof(struct tcphdr); + tx_proto = "tcp"; + } else if (c == 'u') { + ip->ip_p = IPPROTO_UDP; + ip->ip_len += sizeof(struct udphdr); + tx_proto = "udp"; + } else { + ip->ip_p = IPPROTO_ICMP; + ip->ip_len += ICMPERR_IPICMPHLEN; + tx_proto = "icmp"; + } + cpp++; + } else if (ISDIGIT(**cpp) && !index(*cpp, '.')) { + ip->ip_p = atoi(*cpp); + cpp++; + } else + ip->ip_p = IPPROTO_IP; + + if (!*cpp) + return 1; + if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_UDP) { + char *last; + + last = strchr(*cpp, ','); + if (!last) { + fprintf(stderr, "tcp/udp with no source port\n"); + return 1; + } + *last++ = '\0'; + tcp->th_sport = htons(tx_portnum(last)); + if (ip->ip_p == IPPROTO_TCP) { + tcp->th_win = htons(4096); + TCP_OFF_A(tcp, sizeof(*tcp) >> 2); + } + } + ip->ip_src.s_addr = tx_hostnum(*cpp, &r); + cpp++; + if (!*cpp) + return 1; + + if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_UDP) { + char *last; + + last = strchr(*cpp, ','); + if (!last) { + fprintf(stderr, "tcp/udp with no destination port\n"); + return 1; + } + *last++ = '\0'; + tcp->th_dport = htons(tx_portnum(last)); + } + ip->ip_dst.s_addr = tx_hostnum(*cpp, &r); + cpp++; + if (ip->ip_p == IPPROTO_TCP) { + if (*cpp != NULL) { + char *s, *t; + + tcp->th_flags = 0; + for (s = *cpp; *s; s++) + if ((t = strchr(myflagset, *s))) + tcp->th_flags |= myflags[t-myflagset]; + if (tcp->th_flags) + cpp++; + } + + if (tcp->th_flags & TH_URG) + tcp->th_urp = htons(1); + + if (*cpp && !strncasecmp(*cpp, "seq=", 4)) { + tcp->th_seq = htonl(atoi(*cpp + 4)); + cpp++; + } + + if (*cpp && !strncasecmp(*cpp, "ack=", 4)) { + tcp->th_ack = htonl(atoi(*cpp + 4)); + cpp++; + } + } else if (*cpp && ip->ip_p == IPPROTO_ICMP) { + extern char *tx_icmptypes[]; + char **s, *t; + int i; + + t = strchr(*cpp, ','); + if (t != NULL) + *t = '\0'; + + for (s = tx_icmptypes, i = 0; !*s || strcmp(*s, "END"); + s++, i++) { + if (*s && !strcasecmp(*cpp, *s)) { + ic->icmp_type = i; + if (t != NULL) + ic->icmp_code = atoi(t + 1); + cpp++; + break; + } + } + if (t != NULL) + *t = ','; + } + + if (*cpp && !strcasecmp(*cpp, "opt")) { + u_long olen; + + cpp++; + olen = buildopts(*cpp, ipopts, (IP_HL(ip) - 5) << 2); + if (olen) { + bcopy(ipopts, (char *)(ip + 1), olen); + IP_HL_A(ip, IP_HL(ip) + (olen >> 2)); + } + } + if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_UDP) + bcopy((char *)tcp, ((char *)ip) + (IP_HL(ip) << 2), + sizeof(*tcp)); + else if (ip->ip_p == IPPROTO_ICMP) + bcopy((char *)ic, ((char *)ip) + (IP_HL(ip) << 2), + sizeof(*ic)); + ip->ip_len = htons(ip->ip_len); + return 0; +} |
