| /* Shared library add-on to iptables for conntrack matching support. |
| * GPL (C) 2001 Marc Boucher (marc@mbsi.ca). |
| */ |
| |
| #include <stdio.h> |
| #include <netdb.h> |
| #include <string.h> |
| #include <stdlib.h> |
| #include <getopt.h> |
| #include <ctype.h> |
| #include <iptables.h> |
| #include <linux/netfilter_ipv4/ip_conntrack.h> |
| #include <linux/netfilter_ipv4/ip_conntrack_tuple.h> |
| /* For 64bit kernel / 32bit userspace */ |
| #include "../include/linux/netfilter_ipv4/ipt_conntrack.h" |
| |
| #ifndef IPT_CONNTRACK_STATE_UNTRACKED |
| #define IPT_CONNTRACK_STATE_UNTRACKED (1 << (IP_CT_NUMBER + 3)) |
| #endif |
| |
| /* Function which prints out usage message. */ |
| static void |
| help(void) |
| { |
| printf( |
| "conntrack match v%s options:\n" |
| " [!] --ctstate [INVALID|ESTABLISHED|NEW|RELATED|UNTRACKED|SNAT|DNAT][,...]\n" |
| " State(s) to match\n" |
| " [!] --ctproto proto Protocol to match; by number or name, eg. `tcp'\n" |
| " --ctorigsrc [!] address[/mask]\n" |
| " Original source specification\n" |
| " --ctorigdst [!] address[/mask]\n" |
| " Original destination specification\n" |
| " --ctreplsrc [!] address[/mask]\n" |
| " Reply source specification\n" |
| " --ctrepldst [!] address[/mask]\n" |
| " Reply destination specification\n" |
| " [!] --ctstatus [NONE|EXPECTED|SEEN_REPLY|ASSURED|CONFIRMED][,...]\n" |
| " Status(es) to match\n" |
| " [!] --ctexpire time[:time] Match remaining lifetime in seconds against\n" |
| " value or range of values (inclusive)\n" |
| "\n", IPTABLES_VERSION); |
| } |
| |
| |
| |
| static struct option opts[] = { |
| { "ctstate", 1, 0, '1' }, |
| { "ctproto", 1, 0, '2' }, |
| { "ctorigsrc", 1, 0, '3' }, |
| { "ctorigdst", 1, 0, '4' }, |
| { "ctreplsrc", 1, 0, '5' }, |
| { "ctrepldst", 1, 0, '6' }, |
| { "ctstatus", 1, 0, '7' }, |
| { "ctexpire", 1, 0, '8' }, |
| {0} |
| }; |
| |
| /* Initialize the match. */ |
| static void |
| init(struct ipt_entry_match *m, unsigned int *nfcache) |
| { |
| /* Can't cache this */ |
| *nfcache |= NFC_UNKNOWN; |
| } |
| |
| static int |
| parse_state(const char *state, size_t strlen, struct ipt_conntrack_info *sinfo) |
| { |
| if (strncasecmp(state, "INVALID", strlen) == 0) |
| sinfo->statemask |= IPT_CONNTRACK_STATE_INVALID; |
| else if (strncasecmp(state, "NEW", strlen) == 0) |
| sinfo->statemask |= IPT_CONNTRACK_STATE_BIT(IP_CT_NEW); |
| else if (strncasecmp(state, "ESTABLISHED", strlen) == 0) |
| sinfo->statemask |= IPT_CONNTRACK_STATE_BIT(IP_CT_ESTABLISHED); |
| else if (strncasecmp(state, "RELATED", strlen) == 0) |
| sinfo->statemask |= IPT_CONNTRACK_STATE_BIT(IP_CT_RELATED); |
| else if (strncasecmp(state, "UNTRACKED", strlen) == 0) |
| sinfo->statemask |= IPT_CONNTRACK_STATE_UNTRACKED; |
| else if (strncasecmp(state, "SNAT", strlen) == 0) |
| sinfo->statemask |= IPT_CONNTRACK_STATE_SNAT; |
| else if (strncasecmp(state, "DNAT", strlen) == 0) |
| sinfo->statemask |= IPT_CONNTRACK_STATE_DNAT; |
| else |
| return 0; |
| return 1; |
| } |
| |
| static void |
| parse_states(const char *arg, struct ipt_conntrack_info *sinfo) |
| { |
| const char *comma; |
| |
| while ((comma = strchr(arg, ',')) != NULL) { |
| if (comma == arg || !parse_state(arg, comma-arg, sinfo)) |
| exit_error(PARAMETER_PROBLEM, "Bad ctstate `%s'", arg); |
| arg = comma+1; |
| } |
| |
| if (strlen(arg) == 0 || !parse_state(arg, strlen(arg), sinfo)) |
| exit_error(PARAMETER_PROBLEM, "Bad ctstate `%s'", arg); |
| } |
| |
| static int |
| parse_status(const char *status, size_t strlen, struct ipt_conntrack_info *sinfo) |
| { |
| if (strncasecmp(status, "NONE", strlen) == 0) |
| sinfo->statusmask |= 0; |
| else if (strncasecmp(status, "EXPECTED", strlen) == 0) |
| sinfo->statusmask |= IPS_EXPECTED; |
| else if (strncasecmp(status, "SEEN_REPLY", strlen) == 0) |
| sinfo->statusmask |= IPS_SEEN_REPLY; |
| else if (strncasecmp(status, "ASSURED", strlen) == 0) |
| sinfo->statusmask |= IPS_ASSURED; |
| #ifdef IPS_CONFIRMED |
| else if (strncasecmp(status, "CONFIRMED", strlen) == 0) |
| sinfo->stausmask |= IPS_CONFIRMED; |
| #endif |
| else |
| return 0; |
| return 1; |
| } |
| |
| static void |
| parse_statuses(const char *arg, struct ipt_conntrack_info *sinfo) |
| { |
| const char *comma; |
| |
| while ((comma = strchr(arg, ',')) != NULL) { |
| if (comma == arg || !parse_status(arg, comma-arg, sinfo)) |
| exit_error(PARAMETER_PROBLEM, "Bad ctstatus `%s'", arg); |
| arg = comma+1; |
| } |
| |
| if (strlen(arg) == 0 || !parse_status(arg, strlen(arg), sinfo)) |
| exit_error(PARAMETER_PROBLEM, "Bad ctstatus `%s'", arg); |
| } |
| |
| #ifdef KERNEL_64_USERSPACE_32 |
| static unsigned long long |
| parse_expire(const char *s) |
| { |
| unsigned long long len; |
| |
| if (string_to_number_ll(s, 0, 0, &len) == -1) |
| exit_error(PARAMETER_PROBLEM, "expire value invalid: `%s'\n", s); |
| else |
| return len; |
| } |
| #else |
| static unsigned long |
| parse_expire(const char *s) |
| { |
| unsigned int len; |
| |
| if (string_to_number(s, 0, 0, &len) == -1) |
| exit_error(PARAMETER_PROBLEM, "expire value invalid: `%s'\n", s); |
| else |
| return len; |
| } |
| #endif |
| |
| /* If a single value is provided, min and max are both set to the value */ |
| static void |
| parse_expires(const char *s, struct ipt_conntrack_info *sinfo) |
| { |
| char *buffer; |
| char *cp; |
| |
| buffer = strdup(s); |
| if ((cp = strchr(buffer, ':')) == NULL) |
| sinfo->expires_min = sinfo->expires_max = parse_expire(buffer); |
| else { |
| *cp = '\0'; |
| cp++; |
| |
| sinfo->expires_min = buffer[0] ? parse_expire(buffer) : 0; |
| sinfo->expires_max = cp[0] ? parse_expire(cp) : -1; |
| } |
| free(buffer); |
| |
| if (sinfo->expires_min > sinfo->expires_max) |
| exit_error(PARAMETER_PROBLEM, |
| #ifdef KERNEL_64_USERSPACE_32 |
| "expire min. range value `%llu' greater than max. " |
| "range value `%llu'", sinfo->expires_min, sinfo->expires_max); |
| #else |
| "expire min. range value `%lu' greater than max. " |
| "range value `%lu'", sinfo->expires_min, sinfo->expires_max); |
| #endif |
| } |
| |
| /* 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) |
| { |
| struct ipt_conntrack_info *sinfo = (struct ipt_conntrack_info *)(*match)->data; |
| char *protocol = NULL; |
| unsigned int naddrs = 0; |
| struct in_addr *addrs = NULL; |
| |
| |
| switch (c) { |
| case '1': |
| check_inverse(optarg, &invert, &optind, 0); |
| |
| parse_states(argv[optind-1], sinfo); |
| if (invert) { |
| sinfo->invflags |= IPT_CONNTRACK_STATE; |
| } |
| sinfo->flags |= IPT_CONNTRACK_STATE; |
| break; |
| |
| case '2': |
| check_inverse(optarg, &invert, &optind, 0); |
| |
| if(invert) |
| sinfo->invflags |= IPT_CONNTRACK_PROTO; |
| |
| /* Canonicalize into lower case */ |
| for (protocol = argv[optind-1]; *protocol; protocol++) |
| *protocol = tolower(*protocol); |
| |
| protocol = argv[optind-1]; |
| sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.protonum = parse_protocol(protocol); |
| |
| if (sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.protonum == 0 |
| && (sinfo->invflags & IPT_INV_PROTO)) |
| exit_error(PARAMETER_PROBLEM, |
| "rule would never match protocol"); |
| |
| sinfo->flags |= IPT_CONNTRACK_PROTO; |
| break; |
| |
| case '3': |
| check_inverse(optarg, &invert, &optind, 9); |
| |
| if (invert) |
| sinfo->invflags |= IPT_CONNTRACK_ORIGSRC; |
| |
| parse_hostnetworkmask(argv[optind-1], &addrs, |
| &sinfo->sipmsk[IP_CT_DIR_ORIGINAL], |
| &naddrs); |
| if(naddrs > 1) |
| exit_error(PARAMETER_PROBLEM, |
| "multiple IP addresses not allowed"); |
| |
| if(naddrs == 1) { |
| sinfo->tuple[IP_CT_DIR_ORIGINAL].src.ip = addrs[0].s_addr; |
| } |
| |
| sinfo->flags |= IPT_CONNTRACK_ORIGSRC; |
| break; |
| |
| case '4': |
| check_inverse(optarg, &invert, &optind, 0); |
| |
| if (invert) |
| sinfo->invflags |= IPT_CONNTRACK_ORIGDST; |
| |
| parse_hostnetworkmask(argv[optind-1], &addrs, |
| &sinfo->dipmsk[IP_CT_DIR_ORIGINAL], |
| &naddrs); |
| if(naddrs > 1) |
| exit_error(PARAMETER_PROBLEM, |
| "multiple IP addresses not allowed"); |
| |
| if(naddrs == 1) { |
| sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.ip = addrs[0].s_addr; |
| } |
| |
| sinfo->flags |= IPT_CONNTRACK_ORIGDST; |
| break; |
| |
| case '5': |
| check_inverse(optarg, &invert, &optind, 0); |
| |
| if (invert) |
| sinfo->invflags |= IPT_CONNTRACK_REPLSRC; |
| |
| parse_hostnetworkmask(argv[optind-1], &addrs, |
| &sinfo->sipmsk[IP_CT_DIR_REPLY], |
| &naddrs); |
| if(naddrs > 1) |
| exit_error(PARAMETER_PROBLEM, |
| "multiple IP addresses not allowed"); |
| |
| if(naddrs == 1) { |
| sinfo->tuple[IP_CT_DIR_REPLY].src.ip = addrs[0].s_addr; |
| } |
| |
| sinfo->flags |= IPT_CONNTRACK_REPLSRC; |
| break; |
| |
| case '6': |
| check_inverse(optarg, &invert, &optind, 0); |
| |
| if (invert) |
| sinfo->invflags |= IPT_CONNTRACK_REPLDST; |
| |
| parse_hostnetworkmask(argv[optind-1], &addrs, |
| &sinfo->dipmsk[IP_CT_DIR_REPLY], |
| &naddrs); |
| if(naddrs > 1) |
| exit_error(PARAMETER_PROBLEM, |
| "multiple IP addresses not allowed"); |
| |
| if(naddrs == 1) { |
| sinfo->tuple[IP_CT_DIR_REPLY].dst.ip = addrs[0].s_addr; |
| } |
| |
| sinfo->flags |= IPT_CONNTRACK_REPLDST; |
| break; |
| |
| case '7': |
| check_inverse(optarg, &invert, &optind, 0); |
| |
| parse_statuses(argv[optind-1], sinfo); |
| if (invert) { |
| sinfo->invflags |= IPT_CONNTRACK_STATUS; |
| } |
| sinfo->flags |= IPT_CONNTRACK_STATUS; |
| break; |
| |
| case '8': |
| check_inverse(optarg, &invert, &optind, 0); |
| |
| parse_expires(argv[optind-1], sinfo); |
| if (invert) { |
| sinfo->invflags |= IPT_CONNTRACK_EXPIRES; |
| } |
| sinfo->flags |= IPT_CONNTRACK_EXPIRES; |
| break; |
| |
| default: |
| return 0; |
| } |
| |
| *flags = sinfo->flags; |
| return 1; |
| } |
| |
| static void |
| final_check(unsigned int flags) |
| { |
| if (!flags) |
| exit_error(PARAMETER_PROBLEM, "You must specify one or more options"); |
| } |
| |
| static void |
| print_state(unsigned int statemask) |
| { |
| const char *sep = ""; |
| |
| if (statemask & IPT_CONNTRACK_STATE_INVALID) { |
| printf("%sINVALID", sep); |
| sep = ","; |
| } |
| if (statemask & IPT_CONNTRACK_STATE_BIT(IP_CT_NEW)) { |
| printf("%sNEW", sep); |
| sep = ","; |
| } |
| if (statemask & IPT_CONNTRACK_STATE_BIT(IP_CT_RELATED)) { |
| printf("%sRELATED", sep); |
| sep = ","; |
| } |
| if (statemask & IPT_CONNTRACK_STATE_BIT(IP_CT_ESTABLISHED)) { |
| printf("%sESTABLISHED", sep); |
| sep = ","; |
| } |
| if (statemask & IPT_CONNTRACK_STATE_UNTRACKED) { |
| printf("%sUNTRACKED", sep); |
| sep = ","; |
| } |
| if (statemask & IPT_CONNTRACK_STATE_SNAT) { |
| printf("%sSNAT", sep); |
| sep = ","; |
| } |
| if (statemask & IPT_CONNTRACK_STATE_DNAT) { |
| printf("%sDNAT", sep); |
| sep = ","; |
| } |
| printf(" "); |
| } |
| |
| static void |
| print_status(unsigned int statusmask) |
| { |
| const char *sep = ""; |
| |
| if (statusmask & IPS_EXPECTED) { |
| printf("%sEXPECTED", sep); |
| sep = ","; |
| } |
| if (statusmask & IPS_SEEN_REPLY) { |
| printf("%sSEEN_REPLY", sep); |
| sep = ","; |
| } |
| if (statusmask & IPS_ASSURED) { |
| printf("%sASSURED", sep); |
| sep = ","; |
| } |
| #ifdef IPS_CONFIRMED |
| if (statusmask & IPS_CONFIRMED) { |
| printf("%sCONFIRMED", sep); |
| sep =","; |
| } |
| #endif |
| if (statusmask == 0) { |
| printf("%sNONE", sep); |
| sep = ","; |
| } |
| printf(" "); |
| } |
| |
| static void |
| print_addr(struct in_addr *addr, struct in_addr *mask, int inv, int numeric) |
| { |
| char buf[BUFSIZ]; |
| |
| if (inv) |
| fputc('!', stdout); |
| |
| if (mask->s_addr == 0L && !numeric) |
| printf("%s ", "anywhere"); |
| else { |
| if (numeric) |
| sprintf(buf, "%s", addr_to_dotted(addr)); |
| else |
| sprintf(buf, "%s", addr_to_anyname(addr)); |
| strcat(buf, mask_to_dotted(mask)); |
| printf("%s ", buf); |
| } |
| } |
| |
| /* Saves the matchinfo in parsable form to stdout. */ |
| static void |
| matchinfo_print(const struct ipt_ip *ip, const struct ipt_entry_match *match, int numeric, const char *optpfx) |
| { |
| struct ipt_conntrack_info *sinfo = (struct ipt_conntrack_info *)match->data; |
| |
| if(sinfo->flags & IPT_CONNTRACK_STATE) { |
| printf("%sctstate ", optpfx); |
| if (sinfo->invflags & IPT_CONNTRACK_STATE) |
| printf("! "); |
| print_state(sinfo->statemask); |
| } |
| |
| if(sinfo->flags & IPT_CONNTRACK_ORIGSRC) { |
| printf("%sctorigsrc ", optpfx); |
| |
| print_addr( |
| (struct in_addr *)&sinfo->tuple[IP_CT_DIR_ORIGINAL].src.ip, |
| &sinfo->sipmsk[IP_CT_DIR_ORIGINAL], |
| sinfo->invflags & IPT_CONNTRACK_ORIGSRC, |
| numeric); |
| } |
| |
| if(sinfo->flags & IPT_CONNTRACK_ORIGDST) { |
| printf("%sctorigdst ", optpfx); |
| |
| print_addr( |
| (struct in_addr *)&sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.ip, |
| &sinfo->dipmsk[IP_CT_DIR_ORIGINAL], |
| sinfo->invflags & IPT_CONNTRACK_ORIGDST, |
| numeric); |
| } |
| |
| if(sinfo->flags & IPT_CONNTRACK_REPLSRC) { |
| printf("%sctreplsrc ", optpfx); |
| |
| print_addr( |
| (struct in_addr *)&sinfo->tuple[IP_CT_DIR_REPLY].src.ip, |
| &sinfo->sipmsk[IP_CT_DIR_REPLY], |
| sinfo->invflags & IPT_CONNTRACK_REPLSRC, |
| numeric); |
| } |
| |
| if(sinfo->flags & IPT_CONNTRACK_REPLDST) { |
| printf("%sctrepldst ", optpfx); |
| |
| print_addr( |
| (struct in_addr *)&sinfo->tuple[IP_CT_DIR_REPLY].dst.ip, |
| &sinfo->dipmsk[IP_CT_DIR_REPLY], |
| sinfo->invflags & IPT_CONNTRACK_REPLDST, |
| numeric); |
| } |
| |
| if(sinfo->flags & IPT_CONNTRACK_STATUS) { |
| printf("%sctstatus ", optpfx); |
| if (sinfo->invflags & IPT_CONNTRACK_STATUS) |
| printf("! "); |
| print_status(sinfo->statusmask); |
| } |
| |
| if(sinfo->flags & IPT_CONNTRACK_EXPIRES) { |
| printf("%sctexpire ", optpfx); |
| if (sinfo->invflags & IPT_CONNTRACK_EXPIRES) |
| printf("! "); |
| |
| #ifdef KERNEL_64_USERSPACE_32 |
| if (sinfo->expires_max == sinfo->expires_min) |
| printf("%llu ", sinfo->expires_min); |
| else |
| printf("%llu:%llu ", sinfo->expires_min, sinfo->expires_max); |
| #else |
| if (sinfo->expires_max == sinfo->expires_min) |
| printf("%lu ", sinfo->expires_min); |
| else |
| printf("%lu:%lu ", sinfo->expires_min, sinfo->expires_max); |
| #endif |
| } |
| } |
| |
| /* Prints out the matchinfo. */ |
| static void |
| print(const struct ipt_ip *ip, |
| const struct ipt_entry_match *match, |
| int numeric) |
| { |
| matchinfo_print(ip, match, numeric, ""); |
| } |
| |
| /* Saves the matchinfo in parsable form to stdout. */ |
| static void save(const struct ipt_ip *ip, const struct ipt_entry_match *match) |
| { |
| matchinfo_print(ip, match, 1, "--"); |
| } |
| |
| static |
| struct iptables_match conntrack |
| = { NULL, |
| "conntrack", |
| IPTABLES_VERSION, |
| IPT_ALIGN(sizeof(struct ipt_conntrack_info)), |
| IPT_ALIGN(sizeof(struct ipt_conntrack_info)), |
| &help, |
| &init, |
| &parse, |
| &final_check, |
| &print, |
| &save, |
| opts |
| }; |
| |
| void _init(void) |
| { |
| register_match(&conntrack); |
| } |