| /* Shared library add-on to iptables to add multiple TCP port support. */ |
| #include <stdio.h> |
| #include <netdb.h> |
| #include <string.h> |
| #include <stdlib.h> |
| #include <getopt.h> |
| #include <iptables.h> |
| #include <linux/netfilter_ipv4/ipt_multiport.h> |
| |
| /* 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", |
| IPTABLES_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) |
| { |
| unsigned int portnum; |
| |
| if (string_to_number(port, 0, 65535, &portnum) != -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 && i<IPT_MULTI_PORTS; cp=next,i++) |
| { |
| next=strchr(cp, ','); |
| if (next) *next++='\0'; |
| ports[i] = parse_port(cp, proto); |
| } |
| if (cp) exit_error(PARAMETER_PROBLEM, "too many ports specified"); |
| free(buffer); |
| return i; |
| } |
| |
| /* Initialize the match. */ |
| static void |
| init(struct ipt_entry_match *m, unsigned int *nfcache) |
| { |
| } |
| |
| static const char * |
| check_proto(const struct ipt_entry *entry) |
| { |
| if (entry->ip.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(" "); |
| } |
| |
| static |
| struct iptables_match multiport |
| = { NULL, |
| "multiport", |
| IPTABLES_VERSION, |
| IPT_ALIGN(sizeof(struct ipt_multiport)), |
| IPT_ALIGN(sizeof(struct ipt_multiport)), |
| &help, |
| &init, |
| &parse, |
| &final_check, |
| &print, |
| &save, |
| opts |
| }; |
| |
| void |
| _init(void) |
| { |
| register_match(&multiport); |
| } |