From 5c306289b8a78a060a12eba5cd86e0efc3533da0 Mon Sep 17 00:00:00 2001 From: marc Date: Mon, 20 Mar 2000 06:03:29 +0000 Subject: reorganized tree after kernel merge --- extensions/libipt_multiport.c | 262 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 262 insertions(+) create mode 100644 extensions/libipt_multiport.c (limited to 'extensions/libipt_multiport.c') diff --git a/extensions/libipt_multiport.c b/extensions/libipt_multiport.c new file mode 100644 index 0000000..727f95f --- /dev/null +++ b/extensions/libipt_multiport.c @@ -0,0 +1,262 @@ +/* Shared library add-on to iptables to add multiple TCP port support. */ +#include +#include +#include +#include +#include +#include +#include + +/* Function which prints out usage message. */ +static void +help(void) +{ + printf( +"multiport v%s options:\n" +" --source-ports port[,port,port...]\n" +" --sports ...\n" +" match source port(s)\n" +" --destination-ports port[,port,port...]\n" +" --dports ...\n" +" match destination port(s)\n" +" --ports port[,port,port]\n" +" match both source and destination port(s)\n", +NETFILTER_VERSION); +} + +static struct option opts[] = { + { "source-ports", 1, 0, '1' }, + { "sports", 1, 0, '1' }, /* synonym */ + { "destination-ports", 1, 0, '2' }, + { "dports", 1, 0, '2' }, /* synonym */ + { "ports", 1, 0, '3' }, + {0} +}; + +static int +service_to_port(const char *name, const char *proto) +{ + struct servent *service; + + if ((service = getservbyname(name, proto)) != NULL) + return ntohs((unsigned short) service->s_port); + + return -1; +} + +static u_int16_t +parse_port(const char *port, const char *proto) +{ + int portnum; + if ((portnum = string_to_number(port, 0, 65535)) != -1 || + (portnum = service_to_port(port, proto)) != -1) + return (u_int16_t)portnum; + + exit_error(PARAMETER_PROBLEM, + "invalid port/service `%s' specified", port); +} + +static unsigned int +parse_multi_ports(const char *portstring, u_int16_t *ports, const char *proto) +{ + char *buffer, *cp, *next; + unsigned int i; + + buffer = strdup(portstring); + if (!buffer) exit_error(OTHER_PROBLEM, "strdup failed"); + + for (cp=buffer, i=0; cp && iip.proto == IPPROTO_TCP) + return "tcp"; + else if (entry->ip.proto == IPPROTO_UDP) + return "udp"; + else if (!entry->ip.proto) + exit_error(PARAMETER_PROBLEM, + "multiport needs `-p tcp' or `-p udp'"); + else + exit_error(PARAMETER_PROBLEM, + "multiport only works with TCP or UDP"); +} + +/* Function which parses command options; returns true if it + ate an option */ +static int +parse(int c, char **argv, int invert, unsigned int *flags, + const struct ipt_entry *entry, + unsigned int *nfcache, + struct ipt_entry_match **match) +{ + const char *proto; + struct ipt_multiport *multiinfo + = (struct ipt_multiport *)(*match)->data; + + switch (c) { + case '1': + proto = check_proto(entry); + multiinfo->count = parse_multi_ports(argv[optind-1], + multiinfo->ports, proto); + multiinfo->flags = IPT_MULTIPORT_SOURCE; + *nfcache |= NFC_IP_SRC_PT; + break; + + case '2': + proto = check_proto(entry); + multiinfo->count = parse_multi_ports(argv[optind-1], + multiinfo->ports, proto); + multiinfo->flags = IPT_MULTIPORT_DESTINATION; + *nfcache |= NFC_IP_DST_PT; + break; + + case '3': + proto = check_proto(entry); + multiinfo->count = parse_multi_ports(argv[optind-1], + multiinfo->ports, proto); + multiinfo->flags = IPT_MULTIPORT_EITHER; + *nfcache |= NFC_IP_SRC_PT | NFC_IP_DST_PT; + break; + + default: + return 0; + } + + if (*flags) + exit_error(PARAMETER_PROBLEM, + "multiport can only have one option"); + *flags = 1; + return 1; +} + +/* Final check; must specify something. */ +static void +final_check(unsigned int flags) +{ + if (!flags) + exit_error(PARAMETER_PROBLEM, "multiport expection an option"); +} + +static char * +port_to_service(int port, u_int8_t proto) +{ + struct servent *service; + + if ((service = getservbyport(htons(port), + proto == IPPROTO_TCP ? "tcp" : "udp"))) + return service->s_name; + + return NULL; +} + +static void +print_port(u_int16_t port, u_int8_t protocol, int numeric) +{ + char *service; + + if (numeric || (service = port_to_service(port, protocol)) == NULL) + printf("%u", port); + else + printf("%s", service); +} + +/* Prints out the matchinfo. */ +static void +print(const struct ipt_ip *ip, + const struct ipt_entry_match *match, + int numeric) +{ + const struct ipt_multiport *multiinfo + = (const struct ipt_multiport *)match->data; + unsigned int i; + + printf("multiport "); + + switch (multiinfo->flags) { + case IPT_MULTIPORT_SOURCE: + printf("sports "); + break; + + case IPT_MULTIPORT_DESTINATION: + printf("dports "); + break; + + case IPT_MULTIPORT_EITHER: + printf("ports "); + break; + + default: + printf("ERROR "); + break; + } + + for (i=0; i < multiinfo->count; i++) { + printf("%s", i ? "," : ""); + print_port(multiinfo->ports[i], ip->proto, numeric); + } + printf(" "); +} + +/* Saves the union ipt_matchinfo in parsable form to stdout. */ +static void save(const struct ipt_ip *ip, const struct ipt_entry_match *match) +{ + const struct ipt_multiport *multiinfo + = (const struct ipt_multiport *)match->data; + unsigned int i; + + switch (multiinfo->flags) { + case IPT_MULTIPORT_SOURCE: + printf("--sports "); + break; + + case IPT_MULTIPORT_DESTINATION: + printf("--dports "); + break; + + case IPT_MULTIPORT_EITHER: + printf("--ports "); + break; + } + + for (i=0; i < multiinfo->count; i++) { + printf("%s", i ? "," : ""); + print_port(multiinfo->ports[i], ip->proto, 0); + } + printf(" "); +} + +struct iptables_match multiport += { NULL, + "multiport", + NETFILTER_VERSION, + sizeof(struct ipt_multiport), + &help, + &init, + &parse, + &final_check, + &print, + &save, + opts +}; + +void +_init(void) +{ + register_match(&multiport); +} -- cgit v1.2.3