/* * (C)opyright 1993,1994,1995 by Darren Reed. * * Redistribution and use in source and binary forms are permitted * provided that this notice is preserved and due credit is given * to the original author and the contributors. */ #ifndef lint static char sccsid[] = "@(#)ip_frag.c 1.11 3/24/96 (C) 1993-1995 Darren Reed"; #endif #if !defined(_KERNEL) && !defined(KERNEL) # include # include #endif #include #include #include #include #include #include #include #include #if !defined(__SVR4) && !defined(__svr4__) # include # include #else # include # include # include # include #endif #include #ifdef sun #include #endif #include #include #include #include #include #include #include #include #include #include #include "ip_fil.h" #include "ip_frag.h" #include "ip_nat.h" #include "ip_state.h" ipfr_t *ipfr_heads[IPFT_SIZE]; ipfrstat_t ipfr_stats; u_long ipfr_inuse = 0; #ifdef _KERNEL extern int ipfr_timer_id; #endif #if SOLARIS # ifdef _KERNEL extern kmutex_t ipf_frag; # else #define bcmp(a,b,c) memcmp(a,b,c) #define bcopy(a,b,c) memmove(b,a,c) # endif #endif ipfrstat_t *ipfr_fragstats() { ipfr_stats.ifs_table = ipfr_heads; ipfr_stats.ifs_inuse = ipfr_inuse; return &ipfr_stats; } /* * add a new entry to the fragment cache, registering it as having come * through this box, with the result of the filter operation. */ int ipfr_newfrag(ip, fin, pass) ip_t *ip; fr_info_t *fin; int pass; { ipfr_t **fp, *fr, frag; u_int idx; frag.ipfr_p = ip->ip_p; idx = ip->ip_p; frag.ipfr_id = ip->ip_id; idx += ip->ip_id; frag.ipfr_tos = ip->ip_tos; frag.ipfr_src.s_addr = ip->ip_src.s_addr; idx += ip->ip_src.s_addr; frag.ipfr_dst.s_addr = ip->ip_dst.s_addr; idx += ip->ip_dst.s_addr; idx *= 127; idx %= IPFT_SIZE; /* * first, make sure it isn't already there... */ MUTEX_ENTER(&ipf_frag); for (fp = &ipfr_heads[idx]; (fr = *fp); fp = &fr->ipfr_next) if (!bcmp((char *)&frag.ipfr_src, (char *)&fr->ipfr_src, IPFR_CMPSZ)) { ipfr_stats.ifs_exists++; MUTEX_EXIT(&ipf_frag); return -1; } if (!(fr = (ipfr_t *)KMALLOC(sizeof(*fr)))) { ipfr_stats.ifs_nomem++; MUTEX_EXIT(&ipf_frag); return -1; } if ((fr->ipfr_next = ipfr_heads[idx])) ipfr_heads[idx]->ipfr_prev = fr; fr->ipfr_prev = NULL; ipfr_heads[idx] = fr; bcopy((char *)&frag.ipfr_src, (char *)&fr->ipfr_src, IPFR_CMPSZ); fr->ipfr_ttl = 120; /* 60 seconds */ fr->ipfr_pass = pass & ~(FR_LOGFIRST|FR_LOG); fr->ipfr_off = (ip->ip_off & 0x1fff) + (fin->fin_dlen >> 3); *fp = fr; ipfr_stats.ifs_new++; ipfr_inuse++; MUTEX_EXIT(&ipf_frag); return 0; } /* * check the fragment cache to see if there is already a record of this packet * with its filter result known. */ int ipfr_knownfrag(ip, fin) ip_t *ip; fr_info_t *fin; { ipfr_t *f, frag; u_int idx; int ret; /* * For fragments, we record protocol, packet id, TOS and both IP#'s * (these should all be the same for all fragments of a packet). */ frag.ipfr_p = ip->ip_p; idx = ip->ip_p; frag.ipfr_id = ip->ip_id; idx += ip->ip_id; frag.ipfr_tos = ip->ip_tos; frag.ipfr_src.s_addr = ip->ip_src.s_addr; idx += ip->ip_src.s_addr; frag.ipfr_dst.s_addr = ip->ip_dst.s_addr; idx += ip->ip_dst.s_addr; idx *= 127; idx %= IPFT_SIZE; MUTEX_ENTER(&ipf_frag); for (f = ipfr_heads[idx]; f; f = f->ipfr_next) if (!bcmp((char *)&frag.ipfr_src, (char *)&f->ipfr_src, IPFR_CMPSZ)) { u_short atoff, off; if (f != ipfr_heads[idx]) { /* * move fragment info. to the top of the list * to speed up searches. */ if ((f->ipfr_prev->ipfr_next = f->ipfr_next)) f->ipfr_next->ipfr_prev = f->ipfr_prev; f->ipfr_next = ipfr_heads[idx]; ipfr_heads[idx]->ipfr_prev = f; f->ipfr_prev = NULL; ipfr_heads[idx] = f; } ret = f->ipfr_pass; off = ip->ip_off; atoff = (off & 0x1fff) - (fin->fin_dlen >> 3); /* * If we've follwed the fragments, and this is the * last (in order), shrink expiration time. */ if (atoff == f->ipfr_off) { if (!(off & IP_MF)) f->ipfr_ttl = 1; else f->ipfr_off = off; } ipfr_stats.ifs_hits++; MUTEX_EXIT(&ipf_frag); return ret; } MUTEX_EXIT(&ipf_frag); return 0; } /* * Free memory in use by fragment state info. kept. */ void ipfr_unload() { ipfr_t **fp, *fr; int idx; #if !SOLARIS && defined(_KERNEL) int s; #endif MUTEX_ENTER(&ipf_frag); SPLNET(s); for (idx = IPFT_SIZE - 1; idx >= 0; idx--) for (fp = &ipfr_heads[idx]; (fr = *fp); ) { *fp = fr->ipfr_next; KFREE(fp); } SPLX(s); MUTEX_EXIT(&ipf_frag); } #ifdef _KERNEL /* * Slowly expire held state for fragments. Timeouts are set * in expectation * of this being called twice per second. */ # if BSD < 199306 int ipfr_slowtimer() #else void ipfr_slowtimer() #endif { ipfr_t **fp, *fr; int s, idx; MUTEX_ENTER(&ipf_frag); SPLNET(s); for (idx = IPFT_SIZE - 1; idx >= 0; idx--) for (fp = &ipfr_heads[idx]; (fr = *fp); ) { --fr->ipfr_ttl; if (fr->ipfr_ttl == 0) { if (fr->ipfr_prev) fr->ipfr_prev->ipfr_next = fr->ipfr_next; if (fr->ipfr_next) fr->ipfr_next->ipfr_prev = fr->ipfr_prev; *fp = fr->ipfr_next; ipfr_stats.ifs_expire++; ipfr_inuse--; KFREE(fp); } else fp = &fr->ipfr_next; } SPLX(s); #if SOLARIS MUTEX_EXIT(&ipf_frag); fr_timeoutstate(); ip_natexpire(); ipfr_timer_id = timeout(ipfr_slowtimer, NULL, HZ/2); #else fr_timeoutstate(); ip_natexpire(); ip_slowtimo(); #endif # if BSD < 199306 return 0; # endif } #endif /* defined(_KERNEL) */