Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 1 | /* Shared library add-on to iptables to add multiple TCP port support. */ |
| 2 | #include <stdio.h> |
| 3 | #include <netdb.h> |
| 4 | #include <string.h> |
| 5 | #include <stdlib.h> |
| 6 | #include <getopt.h> |
| 7 | #include <iptables.h> |
| 8 | #include <linux/netfilter_ipv4/ipt_multiport.h> |
| 9 | |
| 10 | /* Function which prints out usage message. */ |
| 11 | static void |
| 12 | help(void) |
| 13 | { |
| 14 | printf( |
| 15 | "multiport v%s options:\n" |
| 16 | " --source-ports port[,port,port...]\n" |
| 17 | " --sports ...\n" |
| 18 | " match source port(s)\n" |
| 19 | " --destination-ports port[,port,port...]\n" |
| 20 | " --dports ...\n" |
| 21 | " match destination port(s)\n" |
| 22 | " --ports port[,port,port]\n" |
| 23 | " match both source and destination port(s)\n", |
| 24 | NETFILTER_VERSION); |
| 25 | } |
| 26 | |
| 27 | static struct option opts[] = { |
| 28 | { "source-ports", 1, 0, '1' }, |
| 29 | { "sports", 1, 0, '1' }, /* synonym */ |
| 30 | { "destination-ports", 1, 0, '2' }, |
| 31 | { "dports", 1, 0, '2' }, /* synonym */ |
| 32 | { "ports", 1, 0, '3' }, |
| 33 | {0} |
| 34 | }; |
| 35 | |
| 36 | static int |
| 37 | service_to_port(const char *name, const char *proto) |
| 38 | { |
| 39 | struct servent *service; |
| 40 | |
| 41 | if ((service = getservbyname(name, proto)) != NULL) |
| 42 | return ntohs((unsigned short) service->s_port); |
| 43 | |
| 44 | return -1; |
| 45 | } |
| 46 | |
| 47 | static u_int16_t |
| 48 | parse_port(const char *port, const char *proto) |
| 49 | { |
| 50 | int portnum; |
| 51 | if ((portnum = string_to_number(port, 0, 65535)) != -1 || |
| 52 | (portnum = service_to_port(port, proto)) != -1) |
| 53 | return (u_int16_t)portnum; |
| 54 | |
| 55 | exit_error(PARAMETER_PROBLEM, |
| 56 | "invalid port/service `%s' specified", port); |
| 57 | } |
| 58 | |
| 59 | static unsigned int |
| 60 | parse_multi_ports(const char *portstring, u_int16_t *ports, const char *proto) |
| 61 | { |
| 62 | char *buffer, *cp, *next; |
| 63 | unsigned int i; |
| 64 | |
| 65 | buffer = strdup(portstring); |
| 66 | if (!buffer) exit_error(OTHER_PROBLEM, "strdup failed"); |
| 67 | |
| 68 | for (cp=buffer, i=0; cp && i<IPT_MULTI_PORTS; cp=next,i++) |
| 69 | { |
| 70 | next=strchr(cp, ','); |
| 71 | if (next) *next++='\0'; |
| 72 | ports[i] = parse_port(cp, proto); |
| 73 | } |
| 74 | if (cp) exit_error(PARAMETER_PROBLEM, "too many ports specified"); |
| 75 | free(buffer); |
| 76 | return i; |
| 77 | } |
| 78 | |
| 79 | /* Initialize the match. */ |
| 80 | static void |
| 81 | init(struct ipt_entry_match *m, unsigned int *nfcache) |
| 82 | { |
| 83 | } |
| 84 | |
| 85 | static const char * |
| 86 | check_proto(const struct ipt_entry *entry) |
| 87 | { |
| 88 | if (entry->ip.proto == IPPROTO_TCP) |
| 89 | return "tcp"; |
| 90 | else if (entry->ip.proto == IPPROTO_UDP) |
| 91 | return "udp"; |
| 92 | else if (!entry->ip.proto) |
| 93 | exit_error(PARAMETER_PROBLEM, |
| 94 | "multiport needs `-p tcp' or `-p udp'"); |
| 95 | else |
| 96 | exit_error(PARAMETER_PROBLEM, |
| 97 | "multiport only works with TCP or UDP"); |
| 98 | } |
| 99 | |
| 100 | /* Function which parses command options; returns true if it |
| 101 | ate an option */ |
| 102 | static int |
| 103 | parse(int c, char **argv, int invert, unsigned int *flags, |
| 104 | const struct ipt_entry *entry, |
| 105 | unsigned int *nfcache, |
| 106 | struct ipt_entry_match **match) |
| 107 | { |
| 108 | const char *proto; |
| 109 | struct ipt_multiport *multiinfo |
| 110 | = (struct ipt_multiport *)(*match)->data; |
| 111 | |
| 112 | switch (c) { |
| 113 | case '1': |
| 114 | proto = check_proto(entry); |
| 115 | multiinfo->count = parse_multi_ports(argv[optind-1], |
| 116 | multiinfo->ports, proto); |
| 117 | multiinfo->flags = IPT_MULTIPORT_SOURCE; |
| 118 | *nfcache |= NFC_IP_SRC_PT; |
| 119 | break; |
| 120 | |
| 121 | case '2': |
| 122 | proto = check_proto(entry); |
| 123 | multiinfo->count = parse_multi_ports(argv[optind-1], |
| 124 | multiinfo->ports, proto); |
| 125 | multiinfo->flags = IPT_MULTIPORT_DESTINATION; |
| 126 | *nfcache |= NFC_IP_DST_PT; |
| 127 | break; |
| 128 | |
| 129 | case '3': |
| 130 | proto = check_proto(entry); |
| 131 | multiinfo->count = parse_multi_ports(argv[optind-1], |
| 132 | multiinfo->ports, proto); |
| 133 | multiinfo->flags = IPT_MULTIPORT_EITHER; |
| 134 | *nfcache |= NFC_IP_SRC_PT | NFC_IP_DST_PT; |
| 135 | break; |
| 136 | |
| 137 | default: |
| 138 | return 0; |
| 139 | } |
| 140 | |
| 141 | if (*flags) |
| 142 | exit_error(PARAMETER_PROBLEM, |
| 143 | "multiport can only have one option"); |
| 144 | *flags = 1; |
| 145 | return 1; |
| 146 | } |
| 147 | |
| 148 | /* Final check; must specify something. */ |
| 149 | static void |
| 150 | final_check(unsigned int flags) |
| 151 | { |
| 152 | if (!flags) |
| 153 | exit_error(PARAMETER_PROBLEM, "multiport expection an option"); |
| 154 | } |
| 155 | |
| 156 | static char * |
| 157 | port_to_service(int port, u_int8_t proto) |
| 158 | { |
| 159 | struct servent *service; |
| 160 | |
| 161 | if ((service = getservbyport(htons(port), |
| 162 | proto == IPPROTO_TCP ? "tcp" : "udp"))) |
| 163 | return service->s_name; |
| 164 | |
| 165 | return NULL; |
| 166 | } |
| 167 | |
| 168 | static void |
| 169 | print_port(u_int16_t port, u_int8_t protocol, int numeric) |
| 170 | { |
| 171 | char *service; |
| 172 | |
| 173 | if (numeric || (service = port_to_service(port, protocol)) == NULL) |
| 174 | printf("%u", port); |
| 175 | else |
| 176 | printf("%s", service); |
| 177 | } |
| 178 | |
| 179 | /* Prints out the matchinfo. */ |
| 180 | static void |
| 181 | print(const struct ipt_ip *ip, |
| 182 | const struct ipt_entry_match *match, |
| 183 | int numeric) |
| 184 | { |
| 185 | const struct ipt_multiport *multiinfo |
| 186 | = (const struct ipt_multiport *)match->data; |
| 187 | unsigned int i; |
| 188 | |
| 189 | printf("multiport "); |
| 190 | |
| 191 | switch (multiinfo->flags) { |
| 192 | case IPT_MULTIPORT_SOURCE: |
| 193 | printf("sports "); |
| 194 | break; |
| 195 | |
| 196 | case IPT_MULTIPORT_DESTINATION: |
| 197 | printf("dports "); |
| 198 | break; |
| 199 | |
| 200 | case IPT_MULTIPORT_EITHER: |
| 201 | printf("ports "); |
| 202 | break; |
| 203 | |
| 204 | default: |
| 205 | printf("ERROR "); |
| 206 | break; |
| 207 | } |
| 208 | |
| 209 | for (i=0; i < multiinfo->count; i++) { |
| 210 | printf("%s", i ? "," : ""); |
| 211 | print_port(multiinfo->ports[i], ip->proto, numeric); |
| 212 | } |
| 213 | printf(" "); |
| 214 | } |
| 215 | |
| 216 | /* Saves the union ipt_matchinfo in parsable form to stdout. */ |
| 217 | static void save(const struct ipt_ip *ip, const struct ipt_entry_match *match) |
| 218 | { |
| 219 | const struct ipt_multiport *multiinfo |
| 220 | = (const struct ipt_multiport *)match->data; |
| 221 | unsigned int i; |
| 222 | |
| 223 | switch (multiinfo->flags) { |
| 224 | case IPT_MULTIPORT_SOURCE: |
| 225 | printf("--sports "); |
| 226 | break; |
| 227 | |
| 228 | case IPT_MULTIPORT_DESTINATION: |
| 229 | printf("--dports "); |
| 230 | break; |
| 231 | |
| 232 | case IPT_MULTIPORT_EITHER: |
| 233 | printf("--ports "); |
| 234 | break; |
| 235 | } |
| 236 | |
| 237 | for (i=0; i < multiinfo->count; i++) { |
| 238 | printf("%s", i ? "," : ""); |
| 239 | print_port(multiinfo->ports[i], ip->proto, 0); |
| 240 | } |
| 241 | printf(" "); |
| 242 | } |
| 243 | |
| 244 | struct iptables_match multiport |
| 245 | = { NULL, |
| 246 | "multiport", |
| 247 | NETFILTER_VERSION, |
Rusty Russell | 73f72f5 | 2000-07-03 10:17:57 +0000 | [diff] [blame] | 248 | IPT_ALIGN(sizeof(struct ipt_multiport)), |
| 249 | IPT_ALIGN(sizeof(struct ipt_multiport)), |
Marc Boucher | e6869a8 | 2000-03-20 06:03:29 +0000 | [diff] [blame] | 250 | &help, |
| 251 | &init, |
| 252 | &parse, |
| 253 | &final_check, |
| 254 | &print, |
| 255 | &save, |
| 256 | opts |
| 257 | }; |
| 258 | |
| 259 | void |
| 260 | _init(void) |
| 261 | { |
| 262 | register_match(&multiport); |
| 263 | } |