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544 lines
14 KiB
544 lines
14 KiB
/* Shared library add-on to iptables for SCTP matching |
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* |
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* (C) 2003 by Harald Welte <laforge@gnumonks.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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* libipt_ecn.c borrowed heavily from libipt_dscp.c |
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* |
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*/ |
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#include <stdbool.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 <getopt.h> |
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#include <netdb.h> |
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#include <ctype.h> |
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#include <netinet/in.h> |
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#include <xtables.h> |
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#include <linux/netfilter/xt_sctp.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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static void |
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print_chunk(uint32_t chunknum, int numeric); |
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static void sctp_init(struct xt_entry_match *m) |
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{ |
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int i; |
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struct xt_sctp_info *einfo = (struct xt_sctp_info *)m->data; |
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for (i = 0; i < XT_NUM_SCTP_FLAGS; i++) { |
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einfo->flag_info[i].chunktype = -1; |
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} |
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} |
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static void sctp_help(void) |
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{ |
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printf( |
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"sctp 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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"[!] --chunk-types (all|any|none) (chunktype[:flags])+ match if all, any or none of\n" |
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" chunktypes are present\n" |
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"chunktypes - DATA INIT INIT_ACK SACK HEARTBEAT HEARTBEAT_ACK ABORT SHUTDOWN SHUTDOWN_ACK ERROR COOKIE_ECHO COOKIE_ACK ECN_ECNE ECN_CWR SHUTDOWN_COMPLETE ASCONF ASCONF_ACK FORWARD_TSN ALL NONE\n"); |
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} |
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static const struct option sctp_opts[] = { |
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{.name = "source-port", .has_arg = true, .val = '1'}, |
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{.name = "sport", .has_arg = true, .val = '1'}, |
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{.name = "destination-port", .has_arg = true, .val = '2'}, |
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{.name = "dport", .has_arg = true, .val = '2'}, |
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{.name = "chunk-types", .has_arg = true, .val = '3'}, |
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XT_GETOPT_TABLEEND, |
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}; |
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static void |
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parse_sctp_ports(const char *portstring, |
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uint16_t *ports) |
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{ |
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char *buffer; |
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char *cp; |
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buffer = strdup(portstring); |
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DEBUGP("%s\n", portstring); |
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if ((cp = strchr(buffer, ':')) == NULL) { |
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ports[0] = ports[1] = xtables_parse_port(buffer, "sctp"); |
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} |
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else { |
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*cp = '\0'; |
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cp++; |
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ports[0] = buffer[0] ? xtables_parse_port(buffer, "sctp") : 0; |
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ports[1] = cp[0] ? xtables_parse_port(cp, "sctp") : 0xFFFF; |
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if (ports[0] > ports[1]) |
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xtables_error(PARAMETER_PROBLEM, |
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"invalid portrange (min > max)"); |
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} |
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free(buffer); |
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} |
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struct sctp_chunk_names { |
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const char *name; |
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unsigned int chunk_type; |
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const char *valid_flags; |
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}; |
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/*'ALL' and 'NONE' will be treated specially. */ |
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static const struct sctp_chunk_names sctp_chunk_names[] |
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= { { .name = "DATA", .chunk_type = 0, .valid_flags = "----IUBE"}, |
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{ .name = "INIT", .chunk_type = 1, .valid_flags = "--------"}, |
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{ .name = "INIT_ACK", .chunk_type = 2, .valid_flags = "--------"}, |
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{ .name = "SACK", .chunk_type = 3, .valid_flags = "--------"}, |
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{ .name = "HEARTBEAT", .chunk_type = 4, .valid_flags = "--------"}, |
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{ .name = "HEARTBEAT_ACK", .chunk_type = 5, .valid_flags = "--------"}, |
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{ .name = "ABORT", .chunk_type = 6, .valid_flags = "-------T"}, |
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{ .name = "SHUTDOWN", .chunk_type = 7, .valid_flags = "--------"}, |
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{ .name = "SHUTDOWN_ACK", .chunk_type = 8, .valid_flags = "--------"}, |
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{ .name = "ERROR", .chunk_type = 9, .valid_flags = "--------"}, |
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{ .name = "COOKIE_ECHO", .chunk_type = 10, .valid_flags = "--------"}, |
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{ .name = "COOKIE_ACK", .chunk_type = 11, .valid_flags = "--------"}, |
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{ .name = "ECN_ECNE", .chunk_type = 12, .valid_flags = "--------"}, |
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{ .name = "ECN_CWR", .chunk_type = 13, .valid_flags = "--------"}, |
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{ .name = "SHUTDOWN_COMPLETE", .chunk_type = 14, .valid_flags = "-------T"}, |
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{ .name = "ASCONF", .chunk_type = 193, .valid_flags = "--------"}, |
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{ .name = "ASCONF_ACK", .chunk_type = 128, .valid_flags = "--------"}, |
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{ .name = "FORWARD_TSN", .chunk_type = 192, .valid_flags = "--------"}, |
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}; |
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static void |
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save_chunk_flag_info(struct xt_sctp_flag_info *flag_info, |
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int *flag_count, |
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int chunktype, |
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int bit, |
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int set) |
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{ |
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int i; |
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for (i = 0; i < *flag_count; i++) { |
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if (flag_info[i].chunktype == chunktype) { |
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DEBUGP("Previous match found\n"); |
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flag_info[i].chunktype = chunktype; |
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flag_info[i].flag_mask |= (1 << bit); |
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if (set) { |
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flag_info[i].flag |= (1 << bit); |
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} |
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return; |
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} |
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} |
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if (*flag_count == XT_NUM_SCTP_FLAGS) { |
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xtables_error (PARAMETER_PROBLEM, |
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"Number of chunk types with flags exceeds currently allowed limit." |
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"Increasing this limit involves changing IPT_NUM_SCTP_FLAGS and" |
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"recompiling both the kernel space and user space modules\n"); |
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} |
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flag_info[*flag_count].chunktype = chunktype; |
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flag_info[*flag_count].flag_mask |= (1 << bit); |
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if (set) { |
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flag_info[*flag_count].flag |= (1 << bit); |
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} |
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(*flag_count)++; |
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} |
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static void |
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parse_sctp_chunk(struct xt_sctp_info *einfo, |
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const char *chunks) |
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{ |
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char *ptr; |
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char *buffer; |
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unsigned int i, j; |
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int found = 0; |
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char *chunk_flags; |
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buffer = strdup(chunks); |
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DEBUGP("Buffer: %s\n", buffer); |
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SCTP_CHUNKMAP_RESET(einfo->chunkmap); |
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if (!strcasecmp(buffer, "ALL")) { |
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SCTP_CHUNKMAP_SET_ALL(einfo->chunkmap); |
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goto out; |
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} |
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if (!strcasecmp(buffer, "NONE")) { |
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SCTP_CHUNKMAP_RESET(einfo->chunkmap); |
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goto out; |
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} |
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for (ptr = strtok(buffer, ","); ptr; ptr = strtok(NULL, ",")) { |
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found = 0; |
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DEBUGP("Next Chunk type %s\n", ptr); |
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if ((chunk_flags = strchr(ptr, ':')) != NULL) { |
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*chunk_flags++ = 0; |
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} |
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for (i = 0; i < ARRAY_SIZE(sctp_chunk_names); ++i) |
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if (strcasecmp(sctp_chunk_names[i].name, ptr) == 0) { |
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DEBUGP("Chunk num %d\n", sctp_chunk_names[i].chunk_type); |
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SCTP_CHUNKMAP_SET(einfo->chunkmap, |
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sctp_chunk_names[i].chunk_type); |
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found = 1; |
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break; |
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} |
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if (!found) |
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xtables_error(PARAMETER_PROBLEM, |
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"Unknown sctp chunk `%s'", ptr); |
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if (chunk_flags) { |
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DEBUGP("Chunk flags %s\n", chunk_flags); |
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for (j = 0; j < strlen(chunk_flags); j++) { |
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char *p; |
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int bit; |
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if ((p = strchr(sctp_chunk_names[i].valid_flags, |
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toupper(chunk_flags[j]))) != NULL) { |
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bit = p - sctp_chunk_names[i].valid_flags; |
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bit = 7 - bit; |
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save_chunk_flag_info(einfo->flag_info, |
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&(einfo->flag_count), i, bit, |
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isupper(chunk_flags[j])); |
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} else { |
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xtables_error(PARAMETER_PROBLEM, |
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"Invalid flags for chunk type %d\n", i); |
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} |
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} |
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} |
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} |
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out: |
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free(buffer); |
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} |
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static void |
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parse_sctp_chunks(struct xt_sctp_info *einfo, |
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const char *match_type, |
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const char *chunks) |
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{ |
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DEBUGP("Match type: %s Chunks: %s\n", match_type, chunks); |
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if (!strcasecmp(match_type, "ANY")) { |
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einfo->chunk_match_type = SCTP_CHUNK_MATCH_ANY; |
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} else if (!strcasecmp(match_type, "ALL")) { |
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einfo->chunk_match_type = SCTP_CHUNK_MATCH_ALL; |
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} else if (!strcasecmp(match_type, "ONLY")) { |
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einfo->chunk_match_type = SCTP_CHUNK_MATCH_ONLY; |
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} else { |
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xtables_error (PARAMETER_PROBLEM, |
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"Match type has to be one of \"ALL\", \"ANY\" or \"ONLY\""); |
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} |
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SCTP_CHUNKMAP_RESET(einfo->chunkmap); |
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parse_sctp_chunk(einfo, chunks); |
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} |
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static int |
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sctp_parse(int c, char **argv, int invert, unsigned int *flags, |
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const void *entry, struct xt_entry_match **match) |
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{ |
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struct xt_sctp_info *einfo |
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= (struct xt_sctp_info *)(*match)->data; |
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switch (c) { |
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case '1': |
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if (*flags & XT_SCTP_SRC_PORTS) |
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xtables_error(PARAMETER_PROBLEM, |
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"Only one `--source-port' allowed"); |
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einfo->flags |= XT_SCTP_SRC_PORTS; |
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parse_sctp_ports(optarg, einfo->spts); |
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if (invert) |
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einfo->invflags |= XT_SCTP_SRC_PORTS; |
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*flags |= XT_SCTP_SRC_PORTS; |
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break; |
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case '2': |
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if (*flags & XT_SCTP_DEST_PORTS) |
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xtables_error(PARAMETER_PROBLEM, |
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"Only one `--destination-port' allowed"); |
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einfo->flags |= XT_SCTP_DEST_PORTS; |
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parse_sctp_ports(optarg, einfo->dpts); |
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if (invert) |
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einfo->invflags |= XT_SCTP_DEST_PORTS; |
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*flags |= XT_SCTP_DEST_PORTS; |
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break; |
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case '3': |
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if (*flags & XT_SCTP_CHUNK_TYPES) |
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xtables_error(PARAMETER_PROBLEM, |
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"Only one `--chunk-types' allowed"); |
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if (!argv[optind] |
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|| argv[optind][0] == '-' || argv[optind][0] == '!') |
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xtables_error(PARAMETER_PROBLEM, |
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"--chunk-types requires two args"); |
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einfo->flags |= XT_SCTP_CHUNK_TYPES; |
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parse_sctp_chunks(einfo, optarg, argv[optind]); |
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if (invert) |
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einfo->invflags |= XT_SCTP_CHUNK_TYPES; |
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optind++; |
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*flags |= XT_SCTP_CHUNK_TYPES; |
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break; |
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} |
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return 1; |
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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), "sctp"))) |
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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_chunk_flags(uint32_t chunknum, uint8_t chunk_flags, uint8_t chunk_flags_mask) |
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{ |
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int i; |
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DEBUGP("type: %d\tflags: %x\tflag mask: %x\n", chunknum, chunk_flags, |
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chunk_flags_mask); |
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if (chunk_flags_mask) { |
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printf(":"); |
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} |
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for (i = 7; i >= 0; i--) { |
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if (chunk_flags_mask & (1 << i)) { |
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if (chunk_flags & (1 << i)) { |
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printf("%c", sctp_chunk_names[chunknum].valid_flags[7-i]); |
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} else { |
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printf("%c", tolower(sctp_chunk_names[chunknum].valid_flags[7-i])); |
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} |
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} |
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} |
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} |
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static void |
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print_chunk(uint32_t chunknum, int numeric) |
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{ |
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if (numeric) { |
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printf("0x%04X", chunknum); |
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} |
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else { |
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int i; |
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for (i = 0; i < ARRAY_SIZE(sctp_chunk_names); ++i) |
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if (sctp_chunk_names[i].chunk_type == chunknum) |
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printf("%s", sctp_chunk_names[chunknum].name); |
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} |
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} |
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static void |
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print_chunks(const struct xt_sctp_info *einfo, int numeric) |
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{ |
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uint32_t chunk_match_type = einfo->chunk_match_type; |
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const struct xt_sctp_flag_info *flag_info = einfo->flag_info; |
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int flag_count = einfo->flag_count; |
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int i, j; |
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int flag; |
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switch (chunk_match_type) { |
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case SCTP_CHUNK_MATCH_ANY: printf(" any"); break; |
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case SCTP_CHUNK_MATCH_ALL: printf(" all"); break; |
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case SCTP_CHUNK_MATCH_ONLY: printf(" only"); break; |
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default: printf("Never reach here\n"); break; |
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} |
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if (SCTP_CHUNKMAP_IS_CLEAR(einfo->chunkmap)) { |
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printf(" NONE"); |
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goto out; |
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} |
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if (SCTP_CHUNKMAP_IS_ALL_SET(einfo->chunkmap)) { |
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printf(" ALL"); |
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goto out; |
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} |
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flag = 0; |
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for (i = 0; i < 256; i++) { |
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if (SCTP_CHUNKMAP_IS_SET(einfo->chunkmap, i)) { |
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if (flag) |
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printf(","); |
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else |
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putchar(' '); |
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flag = 1; |
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print_chunk(i, numeric); |
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for (j = 0; j < flag_count; j++) { |
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if (flag_info[j].chunktype == i) { |
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print_chunk_flags(i, flag_info[j].flag, |
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flag_info[j].flag_mask); |
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} |
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} |
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} |
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} |
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out: |
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return; |
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} |
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|
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static void |
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sctp_print(const void *ip, const struct xt_entry_match *match, int numeric) |
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{ |
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const struct xt_sctp_info *einfo = |
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(const struct xt_sctp_info *)match->data; |
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printf(" sctp"); |
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|
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if (einfo->flags & XT_SCTP_SRC_PORTS) { |
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print_ports("spt", einfo->spts[0], einfo->spts[1], |
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einfo->invflags & XT_SCTP_SRC_PORTS, |
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numeric); |
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} |
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|
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if (einfo->flags & XT_SCTP_DEST_PORTS) { |
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print_ports("dpt", einfo->dpts[0], einfo->dpts[1], |
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einfo->invflags & XT_SCTP_DEST_PORTS, |
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numeric); |
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} |
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|
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if (einfo->flags & XT_SCTP_CHUNK_TYPES) { |
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/* FIXME: print_chunks() is used in save() where the printing of '!' |
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s taken care of, so we need to do that here as well */ |
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if (einfo->invflags & XT_SCTP_CHUNK_TYPES) { |
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printf(" !"); |
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} |
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print_chunks(einfo, numeric); |
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} |
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} |
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static void sctp_save(const void *ip, const struct xt_entry_match *match) |
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{ |
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const struct xt_sctp_info *einfo = |
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(const struct xt_sctp_info *)match->data; |
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|
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if (einfo->flags & XT_SCTP_SRC_PORTS) { |
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if (einfo->invflags & XT_SCTP_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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|
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if (einfo->flags & XT_SCTP_DEST_PORTS) { |
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if (einfo->invflags & XT_SCTP_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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|
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if (einfo->flags & XT_SCTP_CHUNK_TYPES) { |
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if (einfo->invflags & XT_SCTP_CHUNK_TYPES) |
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printf(" !"); |
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printf(" --chunk-types"); |
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|
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print_chunks(einfo, 0); |
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} |
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} |
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|
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static int sctp_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_sctp_info *einfo = |
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(const struct xt_sctp_info *)params->match->data; |
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char *space = ""; |
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|
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if (!einfo->flags) |
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return 0; |
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|
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xt_xlate_add(xl, "sctp "); |
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|
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if (einfo->flags & XT_SCTP_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_SCTP_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_SCTP_SRC_PORTS ? " !=" : "", |
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einfo->spts[0]); |
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space = " "; |
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} |
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|
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if (einfo->flags & XT_SCTP_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_SCTP_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_SCTP_DEST_PORTS ? " !=" : "", |
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einfo->dpts[0]); |
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} |
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|
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return 1; |
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} |
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|
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static struct xtables_match sctp_match = { |
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.name = "sctp", |
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.family = NFPROTO_UNSPEC, |
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.version = XTABLES_VERSION, |
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.size = XT_ALIGN(sizeof(struct xt_sctp_info)), |
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.userspacesize = XT_ALIGN(sizeof(struct xt_sctp_info)), |
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.help = sctp_help, |
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.init = sctp_init, |
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.parse = sctp_parse, |
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.print = sctp_print, |
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.save = sctp_save, |
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.extra_opts = sctp_opts, |
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.xlate = sctp_xlate, |
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}; |
|
|
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void _init(void) |
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{ |
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xtables_register_match(&sctp_match); |
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}
|
|
|