From a80b6046fa216c26dbc18d587f6255afa8444885 Mon Sep 17 00:00:00 2001 From: Jan Engelhardt Date: Sun, 20 Jan 2008 13:34:07 +0000 Subject: libxt_conntrack r0 Move libipt_conntrack to libxt_conntrack. Signed-off-by: Jan Engelhardt --- extensions/libipt_conntrack.c | 514 --------------------------------------- extensions/libipt_conntrack.man | 49 ---- extensions/libxt_conntrack.c | 517 ++++++++++++++++++++++++++++++++++++++++ extensions/libxt_conntrack.man | 71 ++++++ 4 files changed, 588 insertions(+), 563 deletions(-) delete mode 100644 extensions/libipt_conntrack.c delete mode 100644 extensions/libipt_conntrack.man create mode 100644 extensions/libxt_conntrack.c create mode 100644 extensions/libxt_conntrack.man (limited to 'extensions') diff --git a/extensions/libipt_conntrack.c b/extensions/libipt_conntrack.c deleted file mode 100644 index b0d444a1..00000000 --- a/extensions/libipt_conntrack.c +++ /dev/null @@ -1,514 +0,0 @@ -/* Shared library add-on to iptables for conntrack matching support. - * GPL (C) 2001 Marc Boucher (marc@mbsi.ca). - */ - -#include -#include -#include -#include -#include -#include -#include -#include -/* 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 conntrack_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 const struct option conntrack_opts[] = { - { "ctstate", 1, NULL, '1' }, - { "ctproto", 1, NULL, '2' }, - { "ctorigsrc", 1, NULL, '3' }, - { "ctorigdst", 1, NULL, '4' }, - { "ctreplsrc", 1, NULL, '5' }, - { "ctrepldst", 1, NULL, '6' }, - { "ctstatus", 1, NULL, '7' }, - { "ctexpire", 1, NULL, '8' }, - { } -}; - -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); -} - -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; -} - -/* 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, - "expire min. range value `%lu' greater than max. " - "range value `%lu'", sinfo->expires_min, sinfo->expires_max); -} - -/* Function which parses command options; returns true if it - ate an option */ -static int conntrack_parse(int c, char **argv, int invert, unsigned int *flags, - const void *entry, struct xt_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, 0); - - 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 conntrack_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) - printf("! "); - - 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 void *ip, const struct xt_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_PROTO) { - printf("%sctproto ", optpfx); - if (sinfo->invflags & IPT_CONNTRACK_PROTO) - printf("! "); - printf("%u ", sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.protonum); - } - - 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("! "); - - if (sinfo->expires_max == sinfo->expires_min) - printf("%lu ", sinfo->expires_min); - else - printf("%lu:%lu ", sinfo->expires_min, sinfo->expires_max); - } -} - -/* Prints out the matchinfo. */ -static void conntrack_print(const void *ip, const struct xt_entry_match *match, - int numeric) -{ - matchinfo_print(ip, match, numeric, ""); -} - -/* Saves the matchinfo in parsable form to stdout. */ -static void conntrack_save(const void *ip, const struct xt_entry_match *match) -{ - matchinfo_print(ip, match, 1, "--"); -} - -static struct iptables_match conntrack_match = { - .name = "conntrack", - .version = IPTABLES_VERSION, - .size = IPT_ALIGN(sizeof(struct ipt_conntrack_info)), - .userspacesize = IPT_ALIGN(sizeof(struct ipt_conntrack_info)), - .help = conntrack_help, - .parse = conntrack_parse, - .final_check = conntrack_check, - .print = conntrack_print, - .save = conntrack_save, - .extra_opts = conntrack_opts, -}; - -void _init(void) -{ - register_match(&conntrack_match); -} diff --git a/extensions/libipt_conntrack.man b/extensions/libipt_conntrack.man deleted file mode 100644 index b732b28e..00000000 --- a/extensions/libipt_conntrack.man +++ /dev/null @@ -1,49 +0,0 @@ -This module, when combined with connection tracking, allows access to -more connection tracking information than the "state" match. -(this module is present only if iptables was compiled under a kernel -supporting this feature) -.TP -.BI "--ctstate " "state" -Where state is a comma separated list of the connection states to -match. Possible states are -.B INVALID -meaning that the packet is associated with no known connection, -.B ESTABLISHED -meaning that the packet is associated with a connection which has seen -packets in both directions, -.B NEW -meaning that the packet has started a new connection, or otherwise -associated with a connection which has not seen packets in both -directions, and -.B RELATED -meaning that the packet is starting a new connection, but is -associated with an existing connection, such as an FTP data transfer, -or an ICMP error. -.B SNAT -A virtual state, matching if the original source address differs from -the reply destination. -.B DNAT -A virtual state, matching if the original destination differs from the -reply source. -.TP -.BI "--ctproto " "proto" -Protocol to match (by number or name) -.TP -.BI "--ctorigsrc " "[!] \fIaddress\fP[/\fImask\fP]" -Match against original source address -.TP -.BI "--ctorigdst " "[!] \fIaddress\fP[/\fImask\fP]" -Match against original destination address -.TP -.BI "--ctreplsrc " "[!] \fIaddress\fP[/\fImask\fP]" -Match against reply source address -.TP -.BI "--ctrepldst " "[!] \fIaddress\fB[/\fImask\fP]" -Match against reply destination address -.TP -.BI "--ctstatus " "[\fINONE|EXPECTED|SEEN_REPLY|ASSURED\fP][,...]" -Match against internal conntrack states -.TP -.BI "--ctexpire " "\fItime\fP[\fI:time\fP]" -Match remaining lifetime in seconds against given value -or range of values (inclusive) diff --git a/extensions/libxt_conntrack.c b/extensions/libxt_conntrack.c new file mode 100644 index 00000000..a4f9e124 --- /dev/null +++ b/extensions/libxt_conntrack.c @@ -0,0 +1,517 @@ +/* Shared library add-on to iptables for conntrack matching support. + * GPL (C) 2001 Marc Boucher (marc@mbsi.ca). + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* Function which prints out usage message. */ +static void conntrack_mt_help(void) +{ + printf( +"conntrack match 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, e.g. \"tcp\"\n" +"[!] --ctorigsrc address[/mask]\n" +"[!] --ctorigdst address[/mask]\n" +"[!] --ctreplsrc address[/mask]\n" +"[!] --ctrepldst address[/mask]\n" +" Original/Reply source/destination address\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"); +} + +static const struct option conntrack_mt_opts[] = { + {.name = "ctstate", .has_arg = true, .val = '1'}, + {.name = "ctproto", .has_arg = true, .val = '2'}, + {.name = "ctorigsrc", .has_arg = true, .val = '3'}, + {.name = "ctorigdst", .has_arg = true, .val = '4'}, + {.name = "ctreplsrc", .has_arg = true, .val = '5'}, + {.name = "ctrepldst", .has_arg = true, .val = '6'}, + {.name = "ctstatus", .has_arg = true, .val = '7'}, + {.name = "ctexpire", .has_arg = true, .val = '8'}, + {}, +}; + +static int +parse_state(const char *state, size_t strlen, struct xt_conntrack_info *sinfo) +{ + if (strncasecmp(state, "INVALID", strlen) == 0) + sinfo->statemask |= XT_CONNTRACK_STATE_INVALID; + else if (strncasecmp(state, "NEW", strlen) == 0) + sinfo->statemask |= XT_CONNTRACK_STATE_BIT(IP_CT_NEW); + else if (strncasecmp(state, "ESTABLISHED", strlen) == 0) + sinfo->statemask |= XT_CONNTRACK_STATE_BIT(IP_CT_ESTABLISHED); + else if (strncasecmp(state, "RELATED", strlen) == 0) + sinfo->statemask |= XT_CONNTRACK_STATE_BIT(IP_CT_RELATED); + else if (strncasecmp(state, "UNTRACKED", strlen) == 0) + sinfo->statemask |= XT_CONNTRACK_STATE_UNTRACKED; + else if (strncasecmp(state, "SNAT", strlen) == 0) + sinfo->statemask |= XT_CONNTRACK_STATE_SNAT; + else if (strncasecmp(state, "DNAT", strlen) == 0) + sinfo->statemask |= XT_CONNTRACK_STATE_DNAT; + else + return 0; + return 1; +} + +static void +parse_states(const char *arg, struct xt_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 xt_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 xt_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); +} + +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; +} + +/* If a single value is provided, min and max are both set to the value */ +static void +parse_expires(const char *s, struct xt_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, + "expire min. range value `%lu' greater than max. " + "range value `%lu'", sinfo->expires_min, sinfo->expires_max); +} + +/* Function which parses command options; returns true if it + ate an option */ +static int conntrack_parse(int c, char **argv, int invert, unsigned int *flags, + const void *entry, struct xt_entry_match **match) +{ + struct xt_conntrack_info *sinfo = (void *)(*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 |= XT_CONNTRACK_STATE; + } + sinfo->flags |= XT_CONNTRACK_STATE; + break; + + case '2': + check_inverse(optarg, &invert, &optind, 0); + + if(invert) + sinfo->invflags |= XT_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 & XT_INV_PROTO)) + exit_error(PARAMETER_PROBLEM, + "rule would never match protocol"); + + sinfo->flags |= XT_CONNTRACK_PROTO; + break; + + case '3': + check_inverse(optarg, &invert, &optind, 0); + + if (invert) + sinfo->invflags |= XT_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 |= XT_CONNTRACK_ORIGSRC; + break; + + case '4': + check_inverse(optarg, &invert, &optind, 0); + + if (invert) + sinfo->invflags |= XT_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 |= XT_CONNTRACK_ORIGDST; + break; + + case '5': + check_inverse(optarg, &invert, &optind, 0); + + if (invert) + sinfo->invflags |= XT_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 |= XT_CONNTRACK_REPLSRC; + break; + + case '6': + check_inverse(optarg, &invert, &optind, 0); + + if (invert) + sinfo->invflags |= XT_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 |= XT_CONNTRACK_REPLDST; + break; + + case '7': + check_inverse(optarg, &invert, &optind, 0); + + parse_statuses(argv[optind-1], sinfo); + if (invert) { + sinfo->invflags |= XT_CONNTRACK_STATUS; + } + sinfo->flags |= XT_CONNTRACK_STATUS; + break; + + case '8': + check_inverse(optarg, &invert, &optind, 0); + + parse_expires(argv[optind-1], sinfo); + if (invert) { + sinfo->invflags |= XT_CONNTRACK_EXPIRES; + } + sinfo->flags |= XT_CONNTRACK_EXPIRES; + break; + + default: + return 0; + } + + *flags = sinfo->flags; + return 1; +} + +static void conntrack_mt_check(unsigned int flags) +{ + if (flags == 0) + exit_error(PARAMETER_PROBLEM, "You must specify one or more options"); +} + +static void +print_state(unsigned int statemask) +{ + const char *sep = ""; + + if (statemask & XT_CONNTRACK_STATE_INVALID) { + printf("%sINVALID", sep); + sep = ","; + } + if (statemask & XT_CONNTRACK_STATE_BIT(IP_CT_NEW)) { + printf("%sNEW", sep); + sep = ","; + } + if (statemask & XT_CONNTRACK_STATE_BIT(IP_CT_RELATED)) { + printf("%sRELATED", sep); + sep = ","; + } + if (statemask & XT_CONNTRACK_STATE_BIT(IP_CT_ESTABLISHED)) { + printf("%sESTABLISHED", sep); + sep = ","; + } + if (statemask & XT_CONNTRACK_STATE_UNTRACKED) { + printf("%sUNTRACKED", sep); + sep = ","; + } + if (statemask & XT_CONNTRACK_STATE_SNAT) { + printf("%sSNAT", sep); + sep = ","; + } + if (statemask & XT_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) + printf("! "); + + 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 void *ip, const struct xt_entry_match *match, int numeric, const char *optpfx) +{ + struct xt_conntrack_info *sinfo = (void *)match->data; + + if(sinfo->flags & XT_CONNTRACK_STATE) { + if (sinfo->invflags & XT_CONNTRACK_STATE) + printf("! "); + printf("%sctstate ", optpfx); + print_state(sinfo->statemask); + } + + if(sinfo->flags & XT_CONNTRACK_PROTO) { + if (sinfo->invflags & XT_CONNTRACK_PROTO) + printf("! "); + printf("%sctproto ", optpfx); + printf("%u ", sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.protonum); + } + + if(sinfo->flags & XT_CONNTRACK_ORIGSRC) { + if (sinfo->invflags & XT_CONNTRACK_ORIGSRC) + printf("! "); + printf("%sctorigsrc ", optpfx); + + print_addr( + (struct in_addr *)&sinfo->tuple[IP_CT_DIR_ORIGINAL].src.ip, + &sinfo->sipmsk[IP_CT_DIR_ORIGINAL], + false, + numeric); + } + + if(sinfo->flags & XT_CONNTRACK_ORIGDST) { + if (sinfo->invflags & XT_CONNTRACK_ORIGDST) + printf("! "); + printf("%sctorigdst ", optpfx); + + print_addr( + (struct in_addr *)&sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.ip, + &sinfo->dipmsk[IP_CT_DIR_ORIGINAL], + false, + numeric); + } + + if(sinfo->flags & XT_CONNTRACK_REPLSRC) { + if (sinfo->invflags & XT_CONNTRACK_REPLSRC) + printf("! "); + printf("%sctreplsrc ", optpfx); + + print_addr( + (struct in_addr *)&sinfo->tuple[IP_CT_DIR_REPLY].src.ip, + &sinfo->sipmsk[IP_CT_DIR_REPLY], + false, + numeric); + } + + if(sinfo->flags & XT_CONNTRACK_REPLDST) { + if (sinfo->invflags & XT_CONNTRACK_REPLDST) + printf("! "); + printf("%sctrepldst ", optpfx); + + print_addr( + (struct in_addr *)&sinfo->tuple[IP_CT_DIR_REPLY].dst.ip, + &sinfo->dipmsk[IP_CT_DIR_REPLY], + false, + numeric); + } + + if(sinfo->flags & XT_CONNTRACK_STATUS) { + if (sinfo->invflags & XT_CONNTRACK_STATUS) + printf("! "); + printf("%sctstatus ", optpfx); + print_status(sinfo->statusmask); + } + + if(sinfo->flags & XT_CONNTRACK_EXPIRES) { + if (sinfo->invflags & XT_CONNTRACK_EXPIRES) + printf("! "); + printf("%sctexpire ", optpfx); + + if (sinfo->expires_max == sinfo->expires_min) + printf("%lu ", sinfo->expires_min); + else + printf("%lu:%lu ", sinfo->expires_min, sinfo->expires_max); + } +} + +/* Prints out the matchinfo. */ +static void conntrack_print(const void *ip, const struct xt_entry_match *match, + int numeric) +{ + matchinfo_print(ip, match, numeric, ""); +} + +/* Saves the matchinfo in parsable form to stdout. */ +static void conntrack_save(const void *ip, const struct xt_entry_match *match) +{ + matchinfo_print(ip, match, 1, "--"); +} + +static struct xtables_match conntrack_match = { + .version = IPTABLES_VERSION, + .name = "conntrack", + .revision = 0, + .family = AF_INET, + .size = XT_ALIGN(sizeof(struct xt_conntrack_info)), + .userspacesize = XT_ALIGN(sizeof(struct xt_conntrack_info)), + .help = conntrack_mt_help, + .parse = conntrack_parse, + .final_check = conntrack_mt_check, + .print = conntrack_print, + .save = conntrack_save, + .extra_opts = conntrack_mt_opts, +}; + +void _init(void) +{ + xtables_register_match(&conntrack_match); +} diff --git a/extensions/libxt_conntrack.man b/extensions/libxt_conntrack.man new file mode 100644 index 00000000..b852bca9 --- /dev/null +++ b/extensions/libxt_conntrack.man @@ -0,0 +1,71 @@ +This module, when combined with connection tracking, allows access to the +connection tracking state for this packet/connection. +.TP +[\fB!\fR] \fB--ctstate\fR \fIstatelist\fR +\fIstatelist\fR is a comma separated list of the connection states to match. +Possible states are listed below. +.TP +[\fB!\fR] \fB--ctproto\fR \fIl4proto\fR +Layer-4 protocol to match (by number or name) +.TP +[\fB!\fR] \fB--ctorigsrc\fR \fIaddress\fR[\fB/\fR\fImask\fR] +Match against original source address +.TP +[\fB!\fR] \fB--ctorigdst\fR \fIaddress\fR[\fB/\fR\fImask\fR] +Match against original destination address +.TP +[\fB!\fR] \fB--ctreplsrc\fR \fIaddress\fR[\fB/\fR\fImask\fR] +Match against reply source address +.TP +[\fB!\fR] \fB--ctrepldst\fR \fIaddress\fR[\fB/\fR\fImask\fR] +Match against reply destination address +.TP +[\fB!\fR] \fB--ctstatus\fR \fIstatelist\fR +\fIstatuslist\fR is a comma separated list of the connection statuses to match. +Possible statuses are listed below. +.TP +[\fB!\fR] \fB--ctexpire\fR \fItime\fR[\fB:\fR\fItime\fR] +Match remaining lifetime in seconds against given value or range of values +(inclusive) +.PP +States for \fB--ctstate\fR: +.TP +\fBINVALID\fR +meaning that the packet is associated with no known connection +.TP +\fBNEW\fR +meaning that the packet has started a new connection, or otherwise associated +with a connection which has not seen packets in both directions, and +.TP +\fBESTABLISHED\fR +meaning that the packet is associated with a connection which has seen packets +in both directions, +.TP +\fBRELATED\fR +meaning that the packet is starting a new connection, but is associated with an +existing connection, such as an FTP data transfer, or an ICMP error. +.TP +\fBSNAT\fR +A virtual state, matching if the original source address differs from the reply +destination. +.TP +\fBDNAT\fR +A virtual state, matching if the original destination differs from the reply +source. +.PP +Statuses for \fB--ctstatus\fR: +.TP +\fBNONE\fR +None of the below. +.TP +\fBEXPECTED\fR +This is an expected connection (i.e. a conntrack helper set it up) +.TP +\fBSEEN_REPLY\fR +Conntrack has seen packets in both directions. +.TP +\fBASSURED\fR +Conntrack entry should never be early-expired. +.TP +\fBCONFIRMED\fR +Connection is confirmed: originating packet has left box. -- cgit v1.2.3