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