diff options
Diffstat (limited to 'sys/netinet/ip_frag.c')
| -rw-r--r-- | sys/netinet/ip_frag.c | 251 |
1 files changed, 251 insertions, 0 deletions
diff --git a/sys/netinet/ip_frag.c b/sys/netinet/ip_frag.c new file mode 100644 index 00000000000..344423b0d71 --- /dev/null +++ b/sys/netinet/ip_frag.c @@ -0,0 +1,251 @@ +/* + * (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 1.5 1/14/96 (C) 1993-1995 Darren Reed"; +#endif + +#include <string.h> +#include <sys/errno.h> +#include <sys/types.h> +#include <sys/param.h> +#include <sys/file.h> +#include <sys/ioctl.h> +#include <sys/uio.h> +#include <sys/protosw.h> +#include <sys/socket.h> +#if !defined(__SVR4) && !defined(__svr4__) +# include <sys/dir.h> +# include <sys/mbuf.h> +#else +# include <sys/byteorder.h> +# include <sys/dditypes.h> +# include <sys/stream.h> +# include <sys/kmem.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> +#include <netinet/ip_var.h> +#include <netinet/tcp.h> +#include <netinet/udp.h> +#include <netinet/tcpip.h> +#include <netinet/ip_icmp.h> +#include <syslog.h> +#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, pass) +ip_t *ip; +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; + *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) +ip_t *ip; +{ + ipfr_t *f, frag; + u_int idx; + + /* + * 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)) { + 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; + } + ipfr_stats.ifs_hits++; + return f->ipfr_pass; + } + 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 + 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) */ |