| /* Shared library add-on to iptables for DCCP matching |
| * |
| * (C) 2005 by Harald Welte <laforge@netfilter.org> |
| * |
| * This program is distributed under the terms of GNU GPL v2, 1991 |
| * |
| */ |
| #include <stdint.h> |
| #include <stdio.h> |
| #include <string.h> |
| #include <stdlib.h> |
| #include <netdb.h> |
| #include <arpa/inet.h> |
| #include <xtables.h> |
| #include <linux/dccp.h> |
| #include <linux/netfilter/x_tables.h> |
| #include <linux/netfilter/xt_dccp.h> |
| |
| #if 0 |
| #define DEBUGP(format, first...) printf(format, ##first) |
| #define static |
| #else |
| #define DEBUGP(format, fist...) |
| #endif |
| |
| enum { |
| O_SOURCE_PORT = 0, |
| O_DEST_PORT, |
| O_DCCP_TYPES, |
| O_DCCP_OPTION, |
| }; |
| |
| static void dccp_help(void) |
| { |
| printf( |
| "dccp match options\n" |
| "[!] --source-port port[:port] match source port(s)\n" |
| " --sport ...\n" |
| "[!] --destination-port port[:port] match destination port(s)\n" |
| " --dport ...\n" |
| "[!] --dccp-types type[,...] match when packet is one of the given types\n" |
| "[!] --dccp-option option match if option (by number!) is set\n" |
| ); |
| } |
| |
| #define s struct xt_dccp_info |
| static const struct xt_option_entry dccp_opts[] = { |
| {.name = "source-port", .id = O_SOURCE_PORT, .type = XTTYPE_PORTRC, |
| .flags = XTOPT_INVERT | XTOPT_PUT, XTOPT_POINTER(s, spts)}, |
| {.name = "sport", .id = O_SOURCE_PORT, .type = XTTYPE_PORTRC, |
| .flags = XTOPT_INVERT | XTOPT_PUT, XTOPT_POINTER(s, spts)}, |
| {.name = "destination-port", .id = O_DEST_PORT, .type = XTTYPE_PORTRC, |
| .flags = XTOPT_INVERT | XTOPT_PUT, XTOPT_POINTER(s, dpts)}, |
| {.name = "dport", .id = O_DEST_PORT, .type = XTTYPE_PORTRC, |
| .flags = XTOPT_INVERT | XTOPT_PUT, XTOPT_POINTER(s, dpts)}, |
| {.name = "dccp-types", .id = O_DCCP_TYPES, .type = XTTYPE_STRING, |
| .flags = XTOPT_INVERT}, |
| {.name = "dccp-option", .id = O_DCCP_OPTION, .type = XTTYPE_UINT8, |
| .min = 1, .max = UINT8_MAX, .flags = XTOPT_INVERT | XTOPT_PUT, |
| XTOPT_POINTER(s, option)}, |
| XTOPT_TABLEEND, |
| }; |
| #undef s |
| |
| static const char *const dccp_pkt_types[] = { |
| [DCCP_PKT_REQUEST] = "REQUEST", |
| [DCCP_PKT_RESPONSE] = "RESPONSE", |
| [DCCP_PKT_DATA] = "DATA", |
| [DCCP_PKT_ACK] = "ACK", |
| [DCCP_PKT_DATAACK] = "DATAACK", |
| [DCCP_PKT_CLOSEREQ] = "CLOSEREQ", |
| [DCCP_PKT_CLOSE] = "CLOSE", |
| [DCCP_PKT_RESET] = "RESET", |
| [DCCP_PKT_SYNC] = "SYNC", |
| [DCCP_PKT_SYNCACK] = "SYNCACK", |
| [DCCP_PKT_INVALID] = "INVALID", |
| }; |
| |
| /* Bits for type values 11-15 */ |
| #define INVALID_OTHER_TYPE_MASK 0xf800 |
| |
| static uint16_t |
| parse_dccp_types(const char *typestring) |
| { |
| uint16_t typemask = 0; |
| char *ptr, *buffer; |
| |
| buffer = strdup(typestring); |
| |
| for (ptr = strtok(buffer, ","); ptr; ptr = strtok(NULL, ",")) { |
| unsigned int i; |
| for (i = 0; i < ARRAY_SIZE(dccp_pkt_types); ++i) |
| if (!strcasecmp(dccp_pkt_types[i], ptr)) { |
| typemask |= (1 << i); |
| break; |
| } |
| if (i == ARRAY_SIZE(dccp_pkt_types)) |
| xtables_error(PARAMETER_PROBLEM, |
| "Unknown DCCP type `%s'", ptr); |
| } |
| if (typemask & (1 << DCCP_PKT_INVALID)) |
| typemask |= INVALID_OTHER_TYPE_MASK; |
| |
| |
| free(buffer); |
| return typemask; |
| } |
| |
| static void dccp_parse(struct xt_option_call *cb) |
| { |
| struct xt_dccp_info *einfo = cb->data; |
| |
| xtables_option_parse(cb); |
| switch (cb->entry->id) { |
| case O_SOURCE_PORT: |
| einfo->flags |= XT_DCCP_SRC_PORTS; |
| if (cb->invert) |
| einfo->invflags |= XT_DCCP_SRC_PORTS; |
| break; |
| case O_DEST_PORT: |
| einfo->flags |= XT_DCCP_DEST_PORTS; |
| if (cb->invert) |
| einfo->invflags |= XT_DCCP_DEST_PORTS; |
| break; |
| case O_DCCP_TYPES: |
| einfo->flags |= XT_DCCP_TYPE; |
| einfo->typemask = parse_dccp_types(cb->arg); |
| if (cb->invert) |
| einfo->invflags |= XT_DCCP_TYPE; |
| break; |
| case O_DCCP_OPTION: |
| einfo->flags |= XT_DCCP_OPTION; |
| if (cb->invert) |
| einfo->invflags |= XT_DCCP_OPTION; |
| break; |
| } |
| } |
| |
| static const char * |
| port_to_service(int port) |
| { |
| const struct servent *service; |
| |
| if ((service = getservbyport(htons(port), "dccp"))) |
| return service->s_name; |
| |
| return NULL; |
| } |
| |
| static void |
| print_port(uint16_t port, int numeric) |
| { |
| const char *service; |
| |
| if (numeric || (service = port_to_service(port)) == NULL) |
| printf("%u", port); |
| else |
| printf("%s", service); |
| } |
| |
| static void |
| print_ports(const char *name, uint16_t min, uint16_t max, |
| int invert, int numeric) |
| { |
| const char *inv = invert ? "!" : ""; |
| |
| if (min != 0 || max != 0xFFFF || invert) { |
| printf(" %s", name); |
| if (min == max) { |
| printf(":%s", inv); |
| print_port(min, numeric); |
| } else { |
| printf("s:%s", inv); |
| print_port(min, numeric); |
| printf(":"); |
| print_port(max, numeric); |
| } |
| } |
| } |
| |
| static void |
| print_types(uint16_t types, int inverted, int numeric) |
| { |
| int have_type = 0; |
| |
| if (inverted) |
| printf(" !"); |
| |
| printf(" "); |
| while (types) { |
| unsigned int i; |
| |
| for (i = 0; !(types & (1 << i)); i++); |
| |
| if (have_type) |
| printf(","); |
| else |
| have_type = 1; |
| |
| if (numeric) |
| printf("%u", i); |
| else { |
| printf("%s", dccp_pkt_types[i]); |
| |
| if (i == DCCP_PKT_INVALID) |
| break; |
| } |
| |
| types &= ~(1 << i); |
| } |
| } |
| |
| static void |
| print_option(uint8_t option, int invert, int numeric) |
| { |
| if (option || invert) |
| printf(" option=%s%u", invert ? "!" : "", option); |
| } |
| |
| static void |
| dccp_print(const void *ip, const struct xt_entry_match *match, int numeric) |
| { |
| const struct xt_dccp_info *einfo = |
| (const struct xt_dccp_info *)match->data; |
| |
| printf(" dccp"); |
| |
| if (einfo->flags & XT_DCCP_SRC_PORTS) { |
| print_ports("spt", einfo->spts[0], einfo->spts[1], |
| einfo->invflags & XT_DCCP_SRC_PORTS, |
| numeric); |
| } |
| |
| if (einfo->flags & XT_DCCP_DEST_PORTS) { |
| print_ports("dpt", einfo->dpts[0], einfo->dpts[1], |
| einfo->invflags & XT_DCCP_DEST_PORTS, |
| numeric); |
| } |
| |
| if (einfo->flags & XT_DCCP_TYPE) { |
| print_types(einfo->typemask, |
| einfo->invflags & XT_DCCP_TYPE, |
| numeric); |
| } |
| |
| if (einfo->flags & XT_DCCP_OPTION) { |
| print_option(einfo->option, |
| einfo->invflags & XT_DCCP_OPTION, numeric); |
| } |
| } |
| |
| static void dccp_save(const void *ip, const struct xt_entry_match *match) |
| { |
| const struct xt_dccp_info *einfo = |
| (const struct xt_dccp_info *)match->data; |
| |
| if (einfo->flags & XT_DCCP_SRC_PORTS) { |
| if (einfo->invflags & XT_DCCP_SRC_PORTS) |
| printf(" !"); |
| if (einfo->spts[0] != einfo->spts[1]) |
| printf(" --sport %u:%u", |
| einfo->spts[0], einfo->spts[1]); |
| else |
| printf(" --sport %u", einfo->spts[0]); |
| } |
| |
| if (einfo->flags & XT_DCCP_DEST_PORTS) { |
| if (einfo->invflags & XT_DCCP_DEST_PORTS) |
| printf(" !"); |
| if (einfo->dpts[0] != einfo->dpts[1]) |
| printf(" --dport %u:%u", |
| einfo->dpts[0], einfo->dpts[1]); |
| else |
| printf(" --dport %u", einfo->dpts[0]); |
| } |
| |
| if (einfo->flags & XT_DCCP_TYPE) { |
| printf("%s --dccp-types", |
| einfo->invflags & XT_DCCP_TYPE ? " !" : ""); |
| print_types(einfo->typemask, false, 0); |
| } |
| |
| if (einfo->flags & XT_DCCP_OPTION) { |
| printf("%s --dccp-option %u", |
| einfo->invflags & XT_DCCP_OPTION ? " !" : "", |
| einfo->option); |
| } |
| } |
| |
| static const char *const dccp_pkt_types_xlate[] = { |
| [DCCP_PKT_REQUEST] = "request", |
| [DCCP_PKT_RESPONSE] = "response", |
| [DCCP_PKT_DATA] = "data", |
| [DCCP_PKT_ACK] = "ack", |
| [DCCP_PKT_DATAACK] = "dataack", |
| [DCCP_PKT_CLOSEREQ] = "closereq", |
| [DCCP_PKT_CLOSE] = "close", |
| [DCCP_PKT_RESET] = "reset", |
| [DCCP_PKT_SYNC] = "sync", |
| [DCCP_PKT_SYNCACK] = "syncack", |
| [DCCP_PKT_INVALID] = "10-15", |
| }; |
| |
| static int dccp_type_xlate(const struct xt_dccp_info *einfo, |
| struct xt_xlate *xl) |
| { |
| bool have_type = false, set_need = false; |
| uint16_t types = einfo->typemask; |
| |
| if (types & INVALID_OTHER_TYPE_MASK) { |
| types &= ~INVALID_OTHER_TYPE_MASK; |
| types |= 1 << DCCP_PKT_INVALID; |
| } |
| |
| if ((types != 0) && !(types == (types & -types))) { |
| xt_xlate_add(xl, "{"); |
| set_need = true; |
| } |
| |
| while (types) { |
| unsigned int i; |
| |
| for (i = 0; !(types & (1 << i)); i++); |
| |
| if (have_type) |
| xt_xlate_add(xl, ", "); |
| else |
| have_type = true; |
| |
| xt_xlate_add(xl, "%s", dccp_pkt_types_xlate[i]); |
| |
| types &= ~(1 << i); |
| } |
| |
| if (set_need) |
| xt_xlate_add(xl, "}"); |
| |
| return 1; |
| } |
| |
| static int dccp_xlate(struct xt_xlate *xl, |
| const struct xt_xlate_mt_params *params) |
| { |
| const struct xt_dccp_info *einfo = |
| (const struct xt_dccp_info *)params->match->data; |
| char *space = ""; |
| int ret = 1; |
| |
| if (einfo->flags & XT_DCCP_SRC_PORTS) { |
| xt_xlate_add(xl, "dccp sport%s %u", |
| einfo->invflags & XT_DCCP_SRC_PORTS ? " !=" : "", |
| einfo->spts[0]); |
| |
| if (einfo->spts[0] != einfo->spts[1]) |
| xt_xlate_add(xl, "-%u", einfo->spts[1]); |
| |
| space = " "; |
| } |
| |
| if (einfo->flags & XT_DCCP_DEST_PORTS) { |
| xt_xlate_add(xl, "%sdccp dport%s %u", space, |
| einfo->invflags & XT_DCCP_DEST_PORTS ? " !=" : "", |
| einfo->dpts[0]); |
| |
| if (einfo->dpts[0] != einfo->dpts[1]) |
| xt_xlate_add(xl, "-%u", einfo->dpts[1]); |
| |
| space = " "; |
| } |
| |
| if (einfo->flags & XT_DCCP_TYPE && einfo->typemask) { |
| xt_xlate_add(xl, "%sdccp type%s ", space, |
| einfo->invflags & XT_DCCP_TYPE ? " !=" : ""); |
| ret = dccp_type_xlate(einfo, xl); |
| |
| space = " "; |
| } |
| |
| /* FIXME: no dccp option support in nftables yet */ |
| if (einfo->flags & XT_DCCP_OPTION) |
| ret = 0; |
| |
| return ret; |
| } |
| static struct xtables_match dccp_match = { |
| .name = "dccp", |
| .family = NFPROTO_UNSPEC, |
| .version = XTABLES_VERSION, |
| .size = XT_ALIGN(sizeof(struct xt_dccp_info)), |
| .userspacesize = XT_ALIGN(sizeof(struct xt_dccp_info)), |
| .help = dccp_help, |
| .print = dccp_print, |
| .save = dccp_save, |
| .x6_parse = dccp_parse, |
| .x6_options = dccp_opts, |
| .xlate = dccp_xlate, |
| }; |
| |
| void _init(void) |
| { |
| xtables_register_match(&dccp_match); |
| } |