From 587aa64163bb14f70098f450abab9410787fce9d Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Wed, 14 Mar 2007 16:37:25 -0700 Subject: [NETFILTER]: Remove IPv4 only connection tracking/NAT Remove the obsolete IPv4 only connection tracking/NAT as scheduled in feature-removal-schedule. Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- net/ipv4/netfilter/ip_conntrack_ftp.c | 520 ---------------------------------- 1 file changed, 520 deletions(-) delete mode 100644 net/ipv4/netfilter/ip_conntrack_ftp.c (limited to 'net/ipv4/netfilter/ip_conntrack_ftp.c') diff --git a/net/ipv4/netfilter/ip_conntrack_ftp.c b/net/ipv4/netfilter/ip_conntrack_ftp.c deleted file mode 100644 index 92389987e78..00000000000 --- a/net/ipv4/netfilter/ip_conntrack_ftp.c +++ /dev/null @@ -1,520 +0,0 @@ -/* FTP extension for IP connection tracking. */ - -/* (C) 1999-2001 Paul `Rusty' Russell - * (C) 2002-2004 Netfilter Core Team - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - */ - -#include -#include -#include -#include -#include -#include - -#include -#include -#include - -MODULE_LICENSE("GPL"); -MODULE_AUTHOR("Rusty Russell "); -MODULE_DESCRIPTION("ftp connection tracking helper"); - -/* This is slow, but it's simple. --RR */ -static char *ftp_buffer; -static DEFINE_SPINLOCK(ip_ftp_lock); - -#define MAX_PORTS 8 -static unsigned short ports[MAX_PORTS]; -static int ports_c; -module_param_array(ports, ushort, &ports_c, 0400); - -static int loose; -module_param(loose, bool, 0600); - -unsigned int (*ip_nat_ftp_hook)(struct sk_buff **pskb, - enum ip_conntrack_info ctinfo, - enum ip_ct_ftp_type type, - unsigned int matchoff, - unsigned int matchlen, - struct ip_conntrack_expect *exp, - u32 *seq); -EXPORT_SYMBOL_GPL(ip_nat_ftp_hook); - -#if 0 -#define DEBUGP printk -#else -#define DEBUGP(format, args...) -#endif - -static int try_rfc959(const char *, size_t, u_int32_t [], char); -static int try_eprt(const char *, size_t, u_int32_t [], char); -static int try_epsv_response(const char *, size_t, u_int32_t [], char); - -static const struct ftp_search { - const char *pattern; - size_t plen; - char skip; - char term; - enum ip_ct_ftp_type ftptype; - int (*getnum)(const char *, size_t, u_int32_t[], char); -} search[IP_CT_DIR_MAX][2] = { - [IP_CT_DIR_ORIGINAL] = { - { - .pattern = "PORT", - .plen = sizeof("PORT") - 1, - .skip = ' ', - .term = '\r', - .ftptype = IP_CT_FTP_PORT, - .getnum = try_rfc959, - }, - { - .pattern = "EPRT", - .plen = sizeof("EPRT") - 1, - .skip = ' ', - .term = '\r', - .ftptype = IP_CT_FTP_EPRT, - .getnum = try_eprt, - }, - }, - [IP_CT_DIR_REPLY] = { - { - .pattern = "227 ", - .plen = sizeof("227 ") - 1, - .skip = '(', - .term = ')', - .ftptype = IP_CT_FTP_PASV, - .getnum = try_rfc959, - }, - { - .pattern = "229 ", - .plen = sizeof("229 ") - 1, - .skip = '(', - .term = ')', - .ftptype = IP_CT_FTP_EPSV, - .getnum = try_epsv_response, - }, - }, -}; - -static int try_number(const char *data, size_t dlen, u_int32_t array[], - int array_size, char sep, char term) -{ - u_int32_t i, len; - - memset(array, 0, sizeof(array[0])*array_size); - - /* Keep data pointing at next char. */ - for (i = 0, len = 0; len < dlen && i < array_size; len++, data++) { - if (*data >= '0' && *data <= '9') { - array[i] = array[i]*10 + *data - '0'; - } - else if (*data == sep) - i++; - else { - /* Unexpected character; true if it's the - terminator and we're finished. */ - if (*data == term && i == array_size - 1) - return len; - - DEBUGP("Char %u (got %u nums) `%u' unexpected\n", - len, i, *data); - return 0; - } - } - DEBUGP("Failed to fill %u numbers separated by %c\n", array_size, sep); - - return 0; -} - -/* Returns 0, or length of numbers: 192,168,1,1,5,6 */ -static int try_rfc959(const char *data, size_t dlen, u_int32_t array[6], - char term) -{ - return try_number(data, dlen, array, 6, ',', term); -} - -/* Grab port: number up to delimiter */ -static int get_port(const char *data, int start, size_t dlen, char delim, - u_int32_t array[2]) -{ - u_int16_t port = 0; - int i; - - for (i = start; i < dlen; i++) { - /* Finished? */ - if (data[i] == delim) { - if (port == 0) - break; - array[0] = port >> 8; - array[1] = port; - return i + 1; - } - else if (data[i] >= '0' && data[i] <= '9') - port = port*10 + data[i] - '0'; - else /* Some other crap */ - break; - } - return 0; -} - -/* Returns 0, or length of numbers: |1|132.235.1.2|6275| */ -static int try_eprt(const char *data, size_t dlen, u_int32_t array[6], - char term) -{ - char delim; - int length; - - /* First character is delimiter, then "1" for IPv4, then - delimiter again. */ - if (dlen <= 3) return 0; - delim = data[0]; - if (isdigit(delim) || delim < 33 || delim > 126 - || data[1] != '1' || data[2] != delim) - return 0; - - DEBUGP("EPRT: Got |1|!\n"); - /* Now we have IP address. */ - length = try_number(data + 3, dlen - 3, array, 4, '.', delim); - if (length == 0) - return 0; - - DEBUGP("EPRT: Got IP address!\n"); - /* Start offset includes initial "|1|", and trailing delimiter */ - return get_port(data, 3 + length + 1, dlen, delim, array+4); -} - -/* Returns 0, or length of numbers: |||6446| */ -static int try_epsv_response(const char *data, size_t dlen, u_int32_t array[6], - char term) -{ - char delim; - - /* Three delimiters. */ - if (dlen <= 3) return 0; - delim = data[0]; - if (isdigit(delim) || delim < 33 || delim > 126 - || data[1] != delim || data[2] != delim) - return 0; - - return get_port(data, 3, dlen, delim, array+4); -} - -/* Return 1 for match, 0 for accept, -1 for partial. */ -static int find_pattern(const char *data, size_t dlen, - const char *pattern, size_t plen, - char skip, char term, - unsigned int *numoff, - unsigned int *numlen, - u_int32_t array[6], - int (*getnum)(const char *, size_t, u_int32_t[], char)) -{ - size_t i; - - DEBUGP("find_pattern `%s': dlen = %u\n", pattern, dlen); - if (dlen == 0) - return 0; - - if (dlen <= plen) { - /* Short packet: try for partial? */ - if (strnicmp(data, pattern, dlen) == 0) - return -1; - else return 0; - } - - if (strnicmp(data, pattern, plen) != 0) { -#if 0 - size_t i; - - DEBUGP("ftp: string mismatch\n"); - for (i = 0; i < plen; i++) { - DEBUGP("ftp:char %u `%c'(%u) vs `%c'(%u)\n", - i, data[i], data[i], - pattern[i], pattern[i]); - } -#endif - return 0; - } - - DEBUGP("Pattern matches!\n"); - /* Now we've found the constant string, try to skip - to the 'skip' character */ - for (i = plen; data[i] != skip; i++) - if (i == dlen - 1) return -1; - - /* Skip over the last character */ - i++; - - DEBUGP("Skipped up to `%c'!\n", skip); - - *numoff = i; - *numlen = getnum(data + i, dlen - i, array, term); - if (!*numlen) - return -1; - - DEBUGP("Match succeeded!\n"); - return 1; -} - -/* Look up to see if we're just after a \n. */ -static int find_nl_seq(u32 seq, const struct ip_ct_ftp_master *info, int dir) -{ - unsigned int i; - - for (i = 0; i < info->seq_aft_nl_num[dir]; i++) - if (info->seq_aft_nl[dir][i] == seq) - return 1; - return 0; -} - -/* We don't update if it's older than what we have. */ -static void update_nl_seq(u32 nl_seq, struct ip_ct_ftp_master *info, int dir, - struct sk_buff *skb) -{ - unsigned int i, oldest = NUM_SEQ_TO_REMEMBER; - - /* Look for oldest: if we find exact match, we're done. */ - for (i = 0; i < info->seq_aft_nl_num[dir]; i++) { - if (info->seq_aft_nl[dir][i] == nl_seq) - return; - - if (oldest == info->seq_aft_nl_num[dir] - || before(info->seq_aft_nl[dir][i], oldest)) - oldest = i; - } - - if (info->seq_aft_nl_num[dir] < NUM_SEQ_TO_REMEMBER) { - info->seq_aft_nl[dir][info->seq_aft_nl_num[dir]++] = nl_seq; - ip_conntrack_event_cache(IPCT_HELPINFO_VOLATILE, skb); - } else if (oldest != NUM_SEQ_TO_REMEMBER) { - info->seq_aft_nl[dir][oldest] = nl_seq; - ip_conntrack_event_cache(IPCT_HELPINFO_VOLATILE, skb); - } -} - -static int help(struct sk_buff **pskb, - struct ip_conntrack *ct, - enum ip_conntrack_info ctinfo) -{ - unsigned int dataoff, datalen; - struct tcphdr _tcph, *th; - char *fb_ptr; - int ret; - u32 seq, array[6] = { 0 }; - int dir = CTINFO2DIR(ctinfo); - unsigned int matchlen, matchoff; - struct ip_ct_ftp_master *ct_ftp_info = &ct->help.ct_ftp_info; - struct ip_conntrack_expect *exp; - unsigned int i; - int found = 0, ends_in_nl; - typeof(ip_nat_ftp_hook) ip_nat_ftp; - - /* Until there's been traffic both ways, don't look in packets. */ - if (ctinfo != IP_CT_ESTABLISHED - && ctinfo != IP_CT_ESTABLISHED+IP_CT_IS_REPLY) { - DEBUGP("ftp: Conntrackinfo = %u\n", ctinfo); - return NF_ACCEPT; - } - - th = skb_header_pointer(*pskb, ip_hdrlen(*pskb), - sizeof(_tcph), &_tcph); - if (th == NULL) - return NF_ACCEPT; - - dataoff = ip_hdrlen(*pskb) + th->doff * 4; - /* No data? */ - if (dataoff >= (*pskb)->len) { - DEBUGP("ftp: pskblen = %u\n", (*pskb)->len); - return NF_ACCEPT; - } - datalen = (*pskb)->len - dataoff; - - spin_lock_bh(&ip_ftp_lock); - fb_ptr = skb_header_pointer(*pskb, dataoff, - (*pskb)->len - dataoff, ftp_buffer); - BUG_ON(fb_ptr == NULL); - - ends_in_nl = (fb_ptr[datalen - 1] == '\n'); - seq = ntohl(th->seq) + datalen; - - /* Look up to see if we're just after a \n. */ - if (!find_nl_seq(ntohl(th->seq), ct_ftp_info, dir)) { - /* Now if this ends in \n, update ftp info. */ - DEBUGP("ip_conntrack_ftp_help: wrong seq pos %s(%u) or %s(%u)\n", - ct_ftp_info->seq_aft_nl[0][dir] - old_seq_aft_nl_set ? "":"(UNSET) ", old_seq_aft_nl); - ret = NF_ACCEPT; - goto out_update_nl; - } - - /* Initialize IP array to expected address (it's not mentioned - in EPSV responses) */ - array[0] = (ntohl(ct->tuplehash[dir].tuple.src.ip) >> 24) & 0xFF; - array[1] = (ntohl(ct->tuplehash[dir].tuple.src.ip) >> 16) & 0xFF; - array[2] = (ntohl(ct->tuplehash[dir].tuple.src.ip) >> 8) & 0xFF; - array[3] = ntohl(ct->tuplehash[dir].tuple.src.ip) & 0xFF; - - for (i = 0; i < ARRAY_SIZE(search[dir]); i++) { - found = find_pattern(fb_ptr, (*pskb)->len - dataoff, - search[dir][i].pattern, - search[dir][i].plen, - search[dir][i].skip, - search[dir][i].term, - &matchoff, &matchlen, - array, - search[dir][i].getnum); - if (found) break; - } - if (found == -1) { - /* We don't usually drop packets. After all, this is - connection tracking, not packet filtering. - However, it is necessary for accurate tracking in - this case. */ - if (net_ratelimit()) - printk("conntrack_ftp: partial %s %u+%u\n", - search[dir][i].pattern, - ntohl(th->seq), datalen); - ret = NF_DROP; - goto out; - } else if (found == 0) { /* No match */ - ret = NF_ACCEPT; - goto out_update_nl; - } - - DEBUGP("conntrack_ftp: match `%s' (%u bytes at %u)\n", - fb_ptr + matchoff, matchlen, ntohl(th->seq) + matchoff); - - /* Allocate expectation which will be inserted */ - exp = ip_conntrack_expect_alloc(ct); - if (exp == NULL) { - ret = NF_DROP; - goto out; - } - - /* We refer to the reverse direction ("!dir") tuples here, - * because we're expecting something in the other direction. - * Doesn't matter unless NAT is happening. */ - exp->tuple.dst.ip = ct->tuplehash[!dir].tuple.dst.ip; - - if (htonl((array[0] << 24) | (array[1] << 16) | (array[2] << 8) | array[3]) - != ct->tuplehash[dir].tuple.src.ip) { - /* Enrico Scholz's passive FTP to partially RNAT'd ftp - server: it really wants us to connect to a - different IP address. Simply don't record it for - NAT. */ - DEBUGP("conntrack_ftp: NOT RECORDING: %u,%u,%u,%u != %u.%u.%u.%u\n", - array[0], array[1], array[2], array[3], - NIPQUAD(ct->tuplehash[dir].tuple.src.ip)); - - /* Thanks to Cristiano Lincoln Mattos - for reporting this potential - problem (DMZ machines opening holes to internal - networks, or the packet filter itself). */ - if (!loose) { - ret = NF_ACCEPT; - goto out_put_expect; - } - exp->tuple.dst.ip = htonl((array[0] << 24) | (array[1] << 16) - | (array[2] << 8) | array[3]); - } - - exp->tuple.src.ip = ct->tuplehash[!dir].tuple.src.ip; - exp->tuple.dst.u.tcp.port = htons(array[4] << 8 | array[5]); - exp->tuple.src.u.tcp.port = 0; /* Don't care. */ - exp->tuple.dst.protonum = IPPROTO_TCP; - exp->mask = ((struct ip_conntrack_tuple) - { { htonl(0xFFFFFFFF), { 0 } }, - { htonl(0xFFFFFFFF), { .tcp = { htons(0xFFFF) } }, 0xFF }}); - - exp->expectfn = NULL; - exp->flags = 0; - - /* Now, NAT might want to mangle the packet, and register the - * (possibly changed) expectation itself. */ - ip_nat_ftp = rcu_dereference(ip_nat_ftp_hook); - if (ip_nat_ftp) - ret = ip_nat_ftp(pskb, ctinfo, search[dir][i].ftptype, - matchoff, matchlen, exp, &seq); - else { - /* Can't expect this? Best to drop packet now. */ - if (ip_conntrack_expect_related(exp) != 0) - ret = NF_DROP; - else - ret = NF_ACCEPT; - } - -out_put_expect: - ip_conntrack_expect_put(exp); - -out_update_nl: - /* Now if this ends in \n, update ftp info. Seq may have been - * adjusted by NAT code. */ - if (ends_in_nl) - update_nl_seq(seq, ct_ftp_info,dir, *pskb); - out: - spin_unlock_bh(&ip_ftp_lock); - return ret; -} - -static struct ip_conntrack_helper ftp[MAX_PORTS]; -static char ftp_names[MAX_PORTS][sizeof("ftp-65535")]; - -/* Not __exit: called from init() */ -static void ip_conntrack_ftp_fini(void) -{ - int i; - for (i = 0; i < ports_c; i++) { - DEBUGP("ip_ct_ftp: unregistering helper for port %d\n", - ports[i]); - ip_conntrack_helper_unregister(&ftp[i]); - } - - kfree(ftp_buffer); -} - -static int __init ip_conntrack_ftp_init(void) -{ - int i, ret; - char *tmpname; - - ftp_buffer = kmalloc(65536, GFP_KERNEL); - if (!ftp_buffer) - return -ENOMEM; - - if (ports_c == 0) - ports[ports_c++] = FTP_PORT; - - for (i = 0; i < ports_c; i++) { - ftp[i].tuple.src.u.tcp.port = htons(ports[i]); - ftp[i].tuple.dst.protonum = IPPROTO_TCP; - ftp[i].mask.src.u.tcp.port = htons(0xFFFF); - ftp[i].mask.dst.protonum = 0xFF; - ftp[i].max_expected = 1; - ftp[i].timeout = 5 * 60; /* 5 minutes */ - ftp[i].me = THIS_MODULE; - ftp[i].help = help; - - tmpname = &ftp_names[i][0]; - if (ports[i] == FTP_PORT) - sprintf(tmpname, "ftp"); - else - sprintf(tmpname, "ftp-%d", ports[i]); - ftp[i].name = tmpname; - - DEBUGP("ip_ct_ftp: registering helper for port %d\n", - ports[i]); - ret = ip_conntrack_helper_register(&ftp[i]); - - if (ret) { - ip_conntrack_ftp_fini(); - return ret; - } - } - return 0; -} - -module_init(ip_conntrack_ftp_init); -module_exit(ip_conntrack_ftp_fini); -- cgit v1.2.3