diff options
Diffstat (limited to 'sys/contrib/ipfilter/netinet/ip_proxy.c')
| -rw-r--r-- | sys/contrib/ipfilter/netinet/ip_proxy.c | 859 |
1 files changed, 859 insertions, 0 deletions
diff --git a/sys/contrib/ipfilter/netinet/ip_proxy.c b/sys/contrib/ipfilter/netinet/ip_proxy.c new file mode 100644 index 0000000..e492a33 --- /dev/null +++ b/sys/contrib/ipfilter/netinet/ip_proxy.c @@ -0,0 +1,859 @@ +/* $FreeBSD$ */ + +/* + * Copyright (C) 1997-2003 by Darren Reed. + * + * See the IPFILTER.LICENCE file for details on licencing. + */ +#if defined(KERNEL) || defined(_KERNEL) +# undef KERNEL +# undef _KERNEL +# define KERNEL 1 +# define _KERNEL 1 +#endif +#include <sys/errno.h> +#include <sys/types.h> +#include <sys/param.h> +#include <sys/time.h> +#include <sys/file.h> +#if !defined(AIX) +# include <sys/fcntl.h> +#endif +#if !defined(_KERNEL) && !defined(__KERNEL__) +# include <stdio.h> +# include <string.h> +# include <stdlib.h> +# include <ctype.h> +# define _KERNEL +# ifdef __OpenBSD__ +struct file; +# endif +# include <sys/uio.h> +# undef _KERNEL +#endif +#if !defined(linux) +# include <sys/protosw.h> +#endif +#include <sys/socket.h> +#if defined(_KERNEL) +# if !defined(__NetBSD__) && !defined(sun) && !defined(__osf__) && \ + !defined(__OpenBSD__) && !defined(__hpux) && !defined(__sgi) && \ + !defined(AIX) +# include <sys/ctype.h> +# endif +# include <sys/systm.h> +# if !defined(__SVR4) && !defined(__svr4__) +# include <sys/mbuf.h> +# endif +#endif +#if defined(_KERNEL) && (__FreeBSD_version >= 220000) +# include <sys/filio.h> +# include <sys/fcntl.h> +# if (__FreeBSD_version >= 300000) && !defined(IPFILTER_LKM) +# include "opt_ipfilter.h" +# endif +#else +# include <sys/ioctl.h> +#endif +#if defined(__SVR4) || defined(__svr4__) +# include <sys/byteorder.h> +# ifdef _KERNEL +# include <sys/dditypes.h> +# endif +# include <sys/stream.h> +# include <sys/kmem.h> +#endif +#if __FreeBSD_version >= 300000 +# include <sys/queue.h> +#endif +#include <net/if.h> +#ifdef sun +# include <net/af.h> +#endif +#include <net/route.h> +#include <netinet/in.h> +#include <netinet/in_systm.h> +#include <netinet/ip.h> +#ifndef linux +# include <netinet/ip_var.h> +#endif +#include <netinet/tcp.h> +#include <netinet/udp.h> +#include <netinet/ip_icmp.h> +#include "netinet/ip_compat.h" +#include <netinet/tcpip.h> +#include "netinet/ip_fil.h" +#include "netinet/ip_nat.h" +#include "netinet/ip_state.h" +#include "netinet/ip_proxy.h" +#if (__FreeBSD_version >= 300000) +# include <sys/malloc.h> +#endif + +#include "netinet/ip_ftp_pxy.c" +#include "netinet/ip_rcmd_pxy.c" +# include "netinet/ip_pptp_pxy.c" +#if defined(_KERNEL) +# include "netinet/ip_irc_pxy.c" +# include "netinet/ip_raudio_pxy.c" +# include "netinet/ip_netbios_pxy.c" +#endif +#include "netinet/ip_ipsec_pxy.c" +#include "netinet/ip_rpcb_pxy.c" + +/* END OF INCLUDES */ + +#if !defined(lint) +static const char rcsid[] = "@(#)$Id: ip_proxy.c,v 2.62.2.21 2007/06/02 21:22:28 darrenr Exp $"; +#endif + +static int appr_fixseqack __P((fr_info_t *, ip_t *, ap_session_t *, int )); + +#define AP_SESS_SIZE 53 + +#if defined(_KERNEL) +int ipf_proxy_debug = 0; +#else +int ipf_proxy_debug = 2; +#endif +ap_session_t *ap_sess_tab[AP_SESS_SIZE]; +ap_session_t *ap_sess_list = NULL; +aproxy_t *ap_proxylist = NULL; +aproxy_t ap_proxies[] = { +#ifdef IPF_FTP_PROXY + { NULL, "ftp", (char)IPPROTO_TCP, 0, 0, ippr_ftp_init, ippr_ftp_fini, + ippr_ftp_new, NULL, ippr_ftp_in, ippr_ftp_out, NULL, NULL }, +#endif +#ifdef IPF_IRC_PROXY + { NULL, "irc", (char)IPPROTO_TCP, 0, 0, ippr_irc_init, ippr_irc_fini, + ippr_irc_new, NULL, NULL, ippr_irc_out, NULL, NULL }, +#endif +#ifdef IPF_RCMD_PROXY + { NULL, "rcmd", (char)IPPROTO_TCP, 0, 0, ippr_rcmd_init, ippr_rcmd_fini, + ippr_rcmd_new, NULL, ippr_rcmd_in, ippr_rcmd_out, NULL, NULL }, +#endif +#ifdef IPF_RAUDIO_PROXY + { NULL, "raudio", (char)IPPROTO_TCP, 0, 0, ippr_raudio_init, ippr_raudio_fini, + ippr_raudio_new, NULL, ippr_raudio_in, ippr_raudio_out, NULL, NULL }, +#endif +#ifdef IPF_MSNRPC_PROXY + { NULL, "msnrpc", (char)IPPROTO_TCP, 0, 0, ippr_msnrpc_init, ippr_msnrpc_fini, + ippr_msnrpc_new, NULL, ippr_msnrpc_in, ippr_msnrpc_out, NULL, NULL }, +#endif +#ifdef IPF_NETBIOS_PROXY + { NULL, "netbios", (char)IPPROTO_UDP, 0, 0, ippr_netbios_init, ippr_netbios_fini, + NULL, NULL, NULL, ippr_netbios_out, NULL, NULL }, +#endif +#ifdef IPF_IPSEC_PROXY + { NULL, "ipsec", (char)IPPROTO_UDP, 0, 0, + ippr_ipsec_init, ippr_ipsec_fini, ippr_ipsec_new, ippr_ipsec_del, + ippr_ipsec_inout, ippr_ipsec_inout, ippr_ipsec_match, NULL }, +#endif +#ifdef IPF_PPTP_PROXY + { NULL, "pptp", (char)IPPROTO_TCP, 0, 0, + ippr_pptp_init, ippr_pptp_fini, ippr_pptp_new, ippr_pptp_del, + ippr_pptp_inout, ippr_pptp_inout, NULL, NULL }, +#endif +#ifdef IPF_H323_PROXY + { NULL, "h323", (char)IPPROTO_TCP, 0, 0, ippr_h323_init, ippr_h323_fini, + ippr_h323_new, ippr_h323_del, ippr_h323_in, NULL, NULL, NULL }, + { NULL, "h245", (char)IPPROTO_TCP, 0, 0, NULL, NULL, + ippr_h245_new, NULL, NULL, ippr_h245_out, NULL, NULL }, +#endif +#ifdef IPF_RPCB_PROXY +# if 0 + { NULL, "rpcbt", (char)IPPROTO_TCP, 0, 0, + ippr_rpcb_init, ippr_rpcb_fini, ippr_rpcb_new, ippr_rpcb_del, + ippr_rpcb_in, ippr_rpcb_out, NULL, NULL }, +# endif + { NULL, "rpcbu", (char)IPPROTO_UDP, 0, 0, + ippr_rpcb_init, ippr_rpcb_fini, ippr_rpcb_new, ippr_rpcb_del, + ippr_rpcb_in, ippr_rpcb_out, NULL, NULL }, +#endif + { NULL, "", '\0', 0, 0, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL } +}; + +/* + * Dynamically add a new kernel proxy. Ensure that it is unique in the + * collection compiled in and dynamically added. + */ +int appr_add(ap) +aproxy_t *ap; +{ + aproxy_t *a; + + for (a = ap_proxies; a->apr_p; a++) + if ((a->apr_p == ap->apr_p) && + !strncmp(a->apr_label, ap->apr_label, + sizeof(ap->apr_label))) { + if (ipf_proxy_debug > 1) + printf("appr_add: %s/%d already present (B)\n", + a->apr_label, a->apr_p); + return -1; + } + + for (a = ap_proxylist; (a != NULL); a = a->apr_next) + if ((a->apr_p == ap->apr_p) && + !strncmp(a->apr_label, ap->apr_label, + sizeof(ap->apr_label))) { + if (ipf_proxy_debug > 1) + printf("appr_add: %s/%d already present (D)\n", + a->apr_label, a->apr_p); + return -1; + } + ap->apr_next = ap_proxylist; + ap_proxylist = ap; + if (ap->apr_init != NULL) + return (*ap->apr_init)(); + return 0; +} + + +/* + * Check to see if the proxy this control request has come through for + * exists, and if it does and it has a control function then invoke that + * control function. + */ +int appr_ctl(ctl) +ap_ctl_t *ctl; +{ + aproxy_t *a; + int error; + + a = appr_lookup(ctl->apc_p, ctl->apc_label); + if (a == NULL) { + if (ipf_proxy_debug > 1) + printf("appr_ctl: can't find %s/%d\n", + ctl->apc_label, ctl->apc_p); + error = ESRCH; + } else if (a->apr_ctl == NULL) { + if (ipf_proxy_debug > 1) + printf("appr_ctl: no ctl function for %s/%d\n", + ctl->apc_label, ctl->apc_p); + error = ENXIO; + } else { + error = (*a->apr_ctl)(a, ctl); + if ((error != 0) && (ipf_proxy_debug > 1)) + printf("appr_ctl: %s/%d ctl error %d\n", + a->apr_label, a->apr_p, error); + } + return error; +} + + +/* + * Delete a proxy that has been added dynamically from those available. + * If it is in use, return 1 (do not destroy NOW), not in use 0 or -1 + * if it cannot be matched. + */ +int appr_del(ap) +aproxy_t *ap; +{ + aproxy_t *a, **app; + + for (app = &ap_proxylist; ((a = *app) != NULL); app = &a->apr_next) + if (a == ap) { + a->apr_flags |= APR_DELETE; + *app = a->apr_next; + if (ap->apr_ref != 0) { + if (ipf_proxy_debug > 2) + printf("appr_del: orphaning %s/%d\n", + ap->apr_label, ap->apr_p); + return 1; + } + return 0; + } + if (ipf_proxy_debug > 1) + printf("appr_del: proxy %lx not found\n", (u_long)ap); + return -1; +} + + +/* + * Return 1 if the packet is a good match against a proxy, else 0. + */ +int appr_ok(fin, tcp, nat) +fr_info_t *fin; +tcphdr_t *tcp; +ipnat_t *nat; +{ + aproxy_t *apr = nat->in_apr; + u_short dport = nat->in_dport; + + if ((apr == NULL) || (apr->apr_flags & APR_DELETE) || + (fin->fin_p != apr->apr_p)) + return 0; + if ((tcp == NULL) && dport) + return 0; + return 1; +} + + +int appr_ioctl(data, cmd, mode, ctx) +caddr_t data; +ioctlcmd_t cmd; +int mode; +void *ctx; +{ + ap_ctl_t ctl; + u_char *ptr; + int error; + + mode = mode; /* LINT */ + + switch (cmd) + { + case SIOCPROXY : + error = BCOPYIN(data, &ctl, sizeof(ctl)); + if (error != 0) + return EFAULT; + ptr = NULL; + + if (ctl.apc_dsize > 0) { + KMALLOCS(ptr, u_char *, ctl.apc_dsize); + if (ptr == NULL) + error = ENOMEM; + else { + error = copyinptr(ctl.apc_data, ptr, + ctl.apc_dsize); + if (error == 0) + ctl.apc_data = ptr; + } + } else { + ctl.apc_data = NULL; + error = 0; + } + + if (error == 0) + error = appr_ctl(&ctl); + + if (ptr != NULL) { + KFREES(ptr, ctl.apc_dsize); + } + break; + + default : + error = EINVAL; + } + return error; +} + + +/* + * If a proxy has a match function, call that to do extended packet + * matching. + */ +int appr_match(fin, nat) +fr_info_t *fin; +nat_t *nat; +{ + aproxy_t *apr; + ipnat_t *ipn; + int result; + + ipn = nat->nat_ptr; + if (ipf_proxy_debug > 8) + printf("appr_match(%lx,%lx) aps %lx ptr %lx\n", + (u_long)fin, (u_long)nat, (u_long)nat->nat_aps, + (u_long)ipn); + + if ((fin->fin_flx & (FI_SHORT|FI_BAD)) != 0) { + if (ipf_proxy_debug > 0) + printf("appr_match: flx 0x%x (BAD|SHORT)\n", + fin->fin_flx); + return -1; + } + + apr = ipn->in_apr; + if ((apr == NULL) || (apr->apr_flags & APR_DELETE)) { + if (ipf_proxy_debug > 0) + printf("appr_match:apr %lx apr_flags 0x%x\n", + (u_long)apr, apr ? apr->apr_flags : 0); + return -1; + } + + if (apr->apr_match != NULL) { + result = (*apr->apr_match)(fin, nat->nat_aps, nat); + if (result != 0) { + if (ipf_proxy_debug > 4) + printf("appr_match: result %d\n", result); + return -1; + } + } + return 0; +} + + +/* + * Allocate a new application proxy structure and fill it in with the + * relevant details. call the init function once complete, prior to + * returning. + */ +int appr_new(fin, nat) +fr_info_t *fin; +nat_t *nat; +{ + register ap_session_t *aps; + aproxy_t *apr; + + if (ipf_proxy_debug > 8) + printf("appr_new(%lx,%lx) \n", (u_long)fin, (u_long)nat); + + if ((nat->nat_ptr == NULL) || (nat->nat_aps != NULL)) { + if (ipf_proxy_debug > 0) + printf("appr_new: nat_ptr %lx nat_aps %lx\n", + (u_long)nat->nat_ptr, (u_long)nat->nat_aps); + return -1; + } + + apr = nat->nat_ptr->in_apr; + + if ((apr->apr_flags & APR_DELETE) || + (fin->fin_p != apr->apr_p)) { + if (ipf_proxy_debug > 2) + printf("appr_new: apr_flags 0x%x p %d/%d\n", + apr->apr_flags, fin->fin_p, apr->apr_p); + return -1; + } + + KMALLOC(aps, ap_session_t *); + if (!aps) { + if (ipf_proxy_debug > 0) + printf("appr_new: malloc failed (%lu)\n", + (u_long)sizeof(ap_session_t)); + return -1; + } + + bzero((char *)aps, sizeof(*aps)); + aps->aps_p = fin->fin_p; + aps->aps_data = NULL; + aps->aps_apr = apr; + aps->aps_psiz = 0; + if (apr->apr_new != NULL) + if ((*apr->apr_new)(fin, aps, nat) == -1) { + if ((aps->aps_data != NULL) && (aps->aps_psiz != 0)) { + KFREES(aps->aps_data, aps->aps_psiz); + } + KFREE(aps); + if (ipf_proxy_debug > 2) + printf("appr_new: new(%lx) failed\n", + (u_long)apr->apr_new); + return -1; + } + aps->aps_nat = nat; + aps->aps_next = ap_sess_list; + ap_sess_list = aps; + nat->nat_aps = aps; + + return 0; +} + + +/* + * Check to see if a packet should be passed through an active proxy routine + * if one has been setup for it. We don't need to check the checksum here if + * IPFILTER_CKSUM is defined because if it is, a failed check causes FI_BAD + * to be set. + */ +int appr_check(fin, nat) +fr_info_t *fin; +nat_t *nat; +{ +#if SOLARIS && defined(_KERNEL) && (SOLARIS2 >= 6) +# if defined(ICK_VALID) + mb_t *m; +# endif + int dosum = 1; +#endif + tcphdr_t *tcp = NULL; + udphdr_t *udp = NULL; + ap_session_t *aps; + aproxy_t *apr; + ip_t *ip; + short rv; + int err; +#if !defined(_KERNEL) || defined(MENTAT) || defined(__sgi) + u_32_t s1, s2, sd; +#endif + + if (fin->fin_flx & FI_BAD) { + if (ipf_proxy_debug > 0) + printf("appr_check: flx 0x%x (BAD)\n", fin->fin_flx); + return -1; + } + +#ifndef IPFILTER_CKSUM + if ((fin->fin_out == 0) && (fr_checkl4sum(fin) == -1)) { + if (ipf_proxy_debug > 0) + printf("appr_check: l4 checksum failure %d\n", + fin->fin_p); + if (fin->fin_p == IPPROTO_TCP) + frstats[fin->fin_out].fr_tcpbad++; + return -1; + } +#endif + + aps = nat->nat_aps; + if ((aps != NULL) && (aps->aps_p == fin->fin_p)) { + /* + * If there is data in this packet to be proxied then try and + * get it all into the one buffer, else drop it. + */ +#if defined(MENTAT) || defined(HAVE_M_PULLDOWN) + if ((fin->fin_dlen > 0) && !(fin->fin_flx & FI_COALESCE)) + if (fr_coalesce(fin) == -1) { + if (ipf_proxy_debug > 0) + printf("appr_check: fr_coalesce failed %x\n", fin->fin_flx); + return -1; + } +#endif + ip = fin->fin_ip; + + switch (fin->fin_p) + { + case IPPROTO_TCP : + tcp = (tcphdr_t *)fin->fin_dp; + +#if SOLARIS && defined(_KERNEL) && (SOLARIS2 >= 6) && defined(ICK_VALID) + m = fin->fin_qfm; + if (dohwcksum && (m->b_ick_flag == ICK_VALID)) + dosum = 0; +#endif + /* + * Don't bother the proxy with these...or in fact, + * should we free up proxy stuff when seen? + */ + if ((fin->fin_tcpf & TH_RST) != 0) + break; + /*FALLTHROUGH*/ + case IPPROTO_UDP : + udp = (udphdr_t *)fin->fin_dp; + break; + default : + break; + } + + apr = aps->aps_apr; + err = 0; + if (fin->fin_out != 0) { + if (apr->apr_outpkt != NULL) + err = (*apr->apr_outpkt)(fin, aps, nat); + } else { + if (apr->apr_inpkt != NULL) + err = (*apr->apr_inpkt)(fin, aps, nat); + } + + rv = APR_EXIT(err); + if (((ipf_proxy_debug > 0) && (rv != 0)) || + (ipf_proxy_debug > 8)) + printf("appr_check: out %d err %x rv %d\n", + fin->fin_out, err, rv); + if (rv == 1) + return -1; + + if (rv == 2) { + appr_free(apr); + nat->nat_aps = NULL; + return -1; + } + + /* + * If err != 0 then the data size of the packet has changed + * so we need to recalculate the header checksums for the + * packet. + */ +#if !defined(_KERNEL) || defined(MENTAT) || defined(__sgi) + if (err != 0) { + short adjlen = err & 0xffff; + + s1 = LONG_SUM(fin->fin_plen - adjlen); + s2 = LONG_SUM(fin->fin_plen); + CALC_SUMD(s1, s2, sd); + fix_outcksum(fin, &ip->ip_sum, sd); + } +#endif + + /* + * For TCP packets, we may need to adjust the sequence and + * acknowledgement numbers to reflect changes in size of the + * data stream. + * + * For both TCP and UDP, recalculate the layer 4 checksum, + * regardless, as we can't tell (here) if data has been + * changed or not. + */ + if (tcp != NULL) { + err = appr_fixseqack(fin, ip, aps, APR_INC(err)); +#if SOLARIS && defined(_KERNEL) && (SOLARIS2 >= 6) + if (dosum) + tcp->th_sum = fr_cksum(fin->fin_qfm, ip, + IPPROTO_TCP, tcp, + fin->fin_plen); +#else + tcp->th_sum = fr_cksum(fin->fin_m, ip, + IPPROTO_TCP, tcp, + fin->fin_plen); +#endif + } else if ((udp != NULL) && (udp->uh_sum != 0)) { +#if SOLARIS && defined(_KERNEL) && (SOLARIS2 >= 6) + if (dosum) + udp->uh_sum = fr_cksum(fin->fin_qfm, ip, + IPPROTO_UDP, udp, + fin->fin_plen); +#else + udp->uh_sum = fr_cksum(fin->fin_m, ip, + IPPROTO_UDP, udp, + fin->fin_plen); +#endif + } + aps->aps_bytes += fin->fin_plen; + aps->aps_pkts++; + return 1; + } + return 0; +} + + +/* + * Search for an proxy by the protocol it is being used with and its name. + */ +aproxy_t *appr_lookup(pr, name) +u_int pr; +char *name; +{ + aproxy_t *ap; + + if (ipf_proxy_debug > 8) + printf("appr_lookup(%d,%s)\n", pr, name); + + for (ap = ap_proxies; ap->apr_p; ap++) + if ((ap->apr_p == pr) && + !strncmp(name, ap->apr_label, sizeof(ap->apr_label))) { + ap->apr_ref++; + return ap; + } + + for (ap = ap_proxylist; ap; ap = ap->apr_next) + if ((ap->apr_p == pr) && + !strncmp(name, ap->apr_label, sizeof(ap->apr_label))) { + ap->apr_ref++; + return ap; + } + if (ipf_proxy_debug > 2) + printf("appr_lookup: failed for %d/%s\n", pr, name); + return NULL; +} + + +void appr_free(ap) +aproxy_t *ap; +{ + ap->apr_ref--; +} + + +void aps_free(aps) +ap_session_t *aps; +{ + ap_session_t *a, **ap; + aproxy_t *apr; + + if (!aps) + return; + + for (ap = &ap_sess_list; ((a = *ap) != NULL); ap = &a->aps_next) + if (a == aps) { + *ap = a->aps_next; + break; + } + + apr = aps->aps_apr; + if ((apr != NULL) && (apr->apr_del != NULL)) + (*apr->apr_del)(aps); + + if ((aps->aps_data != NULL) && (aps->aps_psiz != 0)) + KFREES(aps->aps_data, aps->aps_psiz); + KFREE(aps); +} + + +/* + * returns 2 if ack or seq number in TCP header is changed, returns 0 otherwise + */ +static int appr_fixseqack(fin, ip, aps, inc) +fr_info_t *fin; +ip_t *ip; +ap_session_t *aps; +int inc; +{ + int sel, ch = 0, out, nlen; + u_32_t seq1, seq2; + tcphdr_t *tcp; + short inc2; + + tcp = (tcphdr_t *)fin->fin_dp; + out = fin->fin_out; + /* + * fin->fin_plen has already been adjusted by 'inc'. + */ + nlen = fin->fin_plen; + nlen -= (IP_HL(ip) << 2) + (TCP_OFF(tcp) << 2); + + inc2 = inc; + inc = (int)inc2; + + if (out != 0) { + seq1 = (u_32_t)ntohl(tcp->th_seq); + sel = aps->aps_sel[out]; + + /* switch to other set ? */ + if ((aps->aps_seqmin[!sel] > aps->aps_seqmin[sel]) && + (seq1 > aps->aps_seqmin[!sel])) { + if (ipf_proxy_debug > 7) + printf("proxy out switch set seq %d -> %d %x > %x\n", + sel, !sel, seq1, + aps->aps_seqmin[!sel]); + sel = aps->aps_sel[out] = !sel; + } + + if (aps->aps_seqoff[sel]) { + seq2 = aps->aps_seqmin[sel] - aps->aps_seqoff[sel]; + if (seq1 > seq2) { + seq2 = aps->aps_seqoff[sel]; + seq1 += seq2; + tcp->th_seq = htonl(seq1); + ch = 1; + } + } + + if (inc && (seq1 > aps->aps_seqmin[!sel])) { + aps->aps_seqmin[sel] = seq1 + nlen - 1; + aps->aps_seqoff[sel] = aps->aps_seqoff[sel] + inc; + if (ipf_proxy_debug > 7) + printf("proxy seq set %d at %x to %d + %d\n", + sel, aps->aps_seqmin[sel], + aps->aps_seqoff[sel], inc); + } + + /***/ + + seq1 = ntohl(tcp->th_ack); + sel = aps->aps_sel[1 - out]; + + /* switch to other set ? */ + if ((aps->aps_ackmin[!sel] > aps->aps_ackmin[sel]) && + (seq1 > aps->aps_ackmin[!sel])) { + if (ipf_proxy_debug > 7) + printf("proxy out switch set ack %d -> %d %x > %x\n", + sel, !sel, seq1, + aps->aps_ackmin[!sel]); + sel = aps->aps_sel[1 - out] = !sel; + } + + if (aps->aps_ackoff[sel] && (seq1 > aps->aps_ackmin[sel])) { + seq2 = aps->aps_ackoff[sel]; + tcp->th_ack = htonl(seq1 - seq2); + ch = 1; + } + } else { + seq1 = ntohl(tcp->th_seq); + sel = aps->aps_sel[out]; + + /* switch to other set ? */ + if ((aps->aps_ackmin[!sel] > aps->aps_ackmin[sel]) && + (seq1 > aps->aps_ackmin[!sel])) { + if (ipf_proxy_debug > 7) + printf("proxy in switch set ack %d -> %d %x > %x\n", + sel, !sel, seq1, aps->aps_ackmin[!sel]); + sel = aps->aps_sel[out] = !sel; + } + + if (aps->aps_ackoff[sel]) { + seq2 = aps->aps_ackmin[sel] - aps->aps_ackoff[sel]; + if (seq1 > seq2) { + seq2 = aps->aps_ackoff[sel]; + seq1 += seq2; + tcp->th_seq = htonl(seq1); + ch = 1; + } + } + + if (inc && (seq1 > aps->aps_ackmin[!sel])) { + aps->aps_ackmin[!sel] = seq1 + nlen - 1; + aps->aps_ackoff[!sel] = aps->aps_ackoff[sel] + inc; + + if (ipf_proxy_debug > 7) + printf("proxy ack set %d at %x to %d + %d\n", + !sel, aps->aps_seqmin[!sel], + aps->aps_seqoff[sel], inc); + } + + /***/ + + seq1 = ntohl(tcp->th_ack); + sel = aps->aps_sel[1 - out]; + + /* switch to other set ? */ + if ((aps->aps_seqmin[!sel] > aps->aps_seqmin[sel]) && + (seq1 > aps->aps_seqmin[!sel])) { + if (ipf_proxy_debug > 7) + printf("proxy in switch set seq %d -> %d %x > %x\n", + sel, !sel, seq1, aps->aps_seqmin[!sel]); + sel = aps->aps_sel[1 - out] = !sel; + } + + if (aps->aps_seqoff[sel] != 0) { + if (ipf_proxy_debug > 7) + printf("sel %d seqoff %d seq1 %x seqmin %x\n", + sel, aps->aps_seqoff[sel], seq1, + aps->aps_seqmin[sel]); + if (seq1 > aps->aps_seqmin[sel]) { + seq2 = aps->aps_seqoff[sel]; + tcp->th_ack = htonl(seq1 - seq2); + ch = 1; + } + } + } + + if (ipf_proxy_debug > 8) + printf("appr_fixseqack: seq %x ack %x\n", + (u_32_t)ntohl(tcp->th_seq), (u_32_t)ntohl(tcp->th_ack)); + return ch ? 2 : 0; +} + + +/* + * Initialise hook for kernel application proxies. + * Call the initialise routine for all the compiled in kernel proxies. + */ +int appr_init() +{ + aproxy_t *ap; + int err = 0; + + for (ap = ap_proxies; ap->apr_p; ap++) { + if (ap->apr_init != NULL) { + err = (*ap->apr_init)(); + if (err != 0) + break; + } + } + return err; +} + + +/* + * Unload hook for kernel application proxies. + * Call the finialise routine for all the compiled in kernel proxies. + */ +void appr_unload() +{ + aproxy_t *ap; + + for (ap = ap_proxies; ap->apr_p; ap++) + if (ap->apr_fini != NULL) + (*ap->apr_fini)(); + for (ap = ap_proxylist; ap; ap = ap->apr_next) + if (ap->apr_fini != NULL) + (*ap->apr_fini)(); +} |
