xref: /csrg-svn/sys/netiso/tuba_subr.c (revision 56681)
1 /*
2  * Copyright (c) 1992 Regents of the University of California.
3  * All rights reserved.
4  *
5  * %sccs.include.redist.c%
6  *
7  *	@(#)tuba_subr.c	7.5 (Berkeley) 11/05/92
8  */
9 
10 #include <sys/param.h>
11 #include <sys/proc.h>
12 #include <sys/systm.h>
13 #include <sys/malloc.h>
14 #include <sys/mbuf.h>
15 #include <sys/socket.h>
16 #include <sys/socketvar.h>
17 #include <sys/protosw.h>
18 #include <sys/errno.h>
19 
20 #include <net/route.h>
21 #include <net/if.h>
22 
23 #include <netinet/in.h>
24 #include <netinet/in_systm.h>
25 #include <netinet/ip.h>
26 #include <netinet/in_pcb.h>
27 #include <netinet/ip_var.h>
28 #include <netinet/ip_icmp.h>
29 #include <netinet/tcp.h>
30 #include <netinet/tcp_fsm.h>
31 #include <netinet/tcp_seq.h>
32 #include <netinet/tcp_timer.h>
33 #include <netinet/tcp_var.h>
34 #include <netinet/tcpip.h>
35 #include <netinet/tcp_debug.h>
36 
37 #include <netiso/argo_debug.h>
38 #include <netiso/iso.h>
39 #include <netiso/clnp.h>
40 #include <netiso/iso_pcb.h>
41 #include <netiso/iso_var.h>
42 #include <netiso/tuba_table.h>
43 
44 static struct	sockaddr_iso null_siso = { sizeof(null_siso), AF_ISO, };
45 extern struct	isopcb tuba_isopcb;
46 extern int	tuba_table_size;
47 extern int	tcppcbcachemiss, tcppredack, tcppreddat, tcprexmtthresh;
48 extern struct 	inpcb *tcp_last_inpcb;
49 extern struct	tcpiphdr tcp_saveti;
50 /*
51  * Tuba initialization
52  */
53 tuba_init()
54 {
55 #define TUBAHDRSIZE (3 /*LLC*/ + 9 /*CLNP Fixed*/ + 42 /*Addresses*/ \
56 		     + 6 /*CLNP Segment*/ + 20 /*TCP*/)
57 
58 	tuba_isopcb.isop_next = tuba_isopcb.isop_prev = &tuba_isopcb;
59 	tuba_isopcb.isop_faddr = &tuba_isopcb.isop_sfaddr;
60 	tuba_isopcb.isop_laddr = &tuba_isopcb.isop_sladdr;
61 	if (max_protohdr < TUBAHDRSIZE)
62 		max_protohdr = TUBAHDRSIZE;
63 	if (max_linkhdr + TUBAHDRSIZE > MHLEN)
64 		panic("tuba_init");
65 }
66 
67 static void
68 tuba_getaddr(error, sum, siso, index)
69 	int *error;
70 	register u_long *sum;
71 	struct sockaddr_iso *siso;
72 	u_long index;
73 {
74 	register struct tuba_cache *tc;
75 	if (index <= tuba_table_size && (tc = tuba_table[index])) {
76 		if (siso) {
77 			*siso = null_siso;
78 			siso->siso_addr = tc->tc_addr;
79 		}
80 		REDUCE(*sum, *sum + tc->tc_sum_out);
81 	} else
82 		*error = 1;
83 }
84 
85 tuba_output(m, tp)
86 	register struct mbuf *m;
87 	struct tcpcb *tp;
88 {
89 	struct isopcb *isop;
90 	register struct tcpiphdr *n;
91 	u_long sum, i;
92 
93 	if (tp == 0 || (n = tp->t_template) == 0 ||
94 	    (isop = (struct isopcb *)tp->t_tuba_pcb) == 0) {
95 		isop = &tuba_isopcb;
96 		n = mtod(m, struct tcpiphdr *);
97 		i = sum = 0;
98 		tuba_getaddr(&i, &sum, tuba_isopcb.isop_faddr,
99 				n->ti_dst.s_addr);
100 		tuba_getaddr(&i, &sum, tuba_isopcb.isop_laddr,
101 				n->ti_src.s_addr);
102 		goto adjust;
103 	}
104 	if (n->ti_sum == 0) {
105 		i = sum = 0;
106 		tuba_getaddr(&i, &sum, (struct sockaddr_iso *)0,
107 				n->ti_dst.s_addr);
108 		tuba_getaddr(&i, &sum, (struct sockaddr_iso *)0,
109 				n->ti_src.s_addr);
110 		n->ti_sum = sum;
111 		n = mtod(m, struct tcpiphdr *);
112 	adjust:
113 		if (i) {
114 			m_freem(m);
115 			return (EADDRNOTAVAIL);
116 		}
117 		REDUCE(n->ti_sum, n->ti_sum + (0xffff ^ sum));
118 	}
119 	m->m_len -= sizeof (struct ip);
120 	m->m_pkthdr.len -= sizeof (struct ip);
121 	m->m_data += sizeof (struct ip);
122 	return (clnp_output(m, isop, m->m_pkthdr.len, 0));
123 }
124 
125 tuba_refcnt(isop, delta)
126 	struct isopcb *isop;
127 {
128 	register struct tuba_cache *tc;
129 	unsigned index, sum;
130 
131 	if (delta != 1)
132 		delta = -1;
133 	if (isop == 0 || isop->isop_faddr == 0 || isop->isop_laddr == 0 ||
134 	    (delta == -1 && isop->isop_tuba_cached == 0) ||
135 	    (delta == 1 && isop->isop_tuba_cached != 0))
136 		return;
137 	isop->isop_tuba_cached = (delta == 1);
138 	if ((index = tuba_lookup(&isop->isop_sfaddr.siso_addr, M_DONTWAIT)) != 0 &&
139 	    (tc = tuba_table[index]) != 0 && (delta == 1 || tc->tc_refcnt > 0))
140 		tc->tc_refcnt += delta;
141 	if ((index = tuba_lookup(&isop->isop_sladdr.siso_addr, M_DONTWAIT)) != 0 &&
142 	    (tc = tuba_table[index]) != 0 && (delta == 1 || tc->tc_refcnt > 0))
143 		tc->tc_refcnt += delta;
144 }
145 
146 tuba_pcbdetach(isop)
147 	struct isopcb *isop;
148 {
149 	if (isop == 0)
150 		return;
151 	tuba_refcnt(isop, -1);
152 	isop->isop_socket = 0;
153 	iso_pcbdetach(isop);
154 }
155 
156 /*
157  * Avoid  in_pcbconnect in faked out tcp_input()
158  */
159 tuba_pcbconnect(inp, nam)
160 	register struct inpcb *inp;
161 	struct mbuf *nam;
162 {
163 	register struct sockaddr_iso *siso = mtod(nam, struct sockaddr_iso *);
164 	struct sockaddr_in *sin = mtod(nam, struct sockaddr_in *);
165 	struct tcpcb *tp = intotcpcb(inp);
166 	unsigned index = sin->sin_addr.s_addr;
167 	struct tuba_cache *tc = tuba_table[index];
168 	struct isopcb *isop = (struct isopcb *)tp->t_tuba_pcb;
169 	int error;
170 
171 	inp->inp_faddr.s_addr = index;
172 	inp->inp_fport = sin->sin_port;
173 	*siso = null_siso;
174 	siso->siso_addr = tc->tc_addr;
175 	siso->siso_tlen = sizeof(inp->inp_fport);
176 	bcopy((caddr_t)&inp->inp_fport, TSEL(siso), sizeof(inp->inp_fport));
177 	nam->m_len = sizeof(*siso);
178 	if ((error = iso_pcbconnect(isop, nam)) == 0)
179 		tuba_refcnt(isop, 1);
180 	return (error);
181 }
182 
183 tuba_badcksum() {} /* XXX - to set breakpoints */
184 
185 /*
186  * CALLED FROM:
187  * 	clnp's input routine, indirectly through the protosw.
188  * FUNCTION and ARGUMENTS:
189  * Take a packet (m) from clnp, strip off the clnp header
190  * and do tcp input processing.
191  * No return value.
192  */
193 tuba_tcpinput(m, src, dst, clnp_len, ce_bit)
194 	register struct mbuf *m;
195 	struct sockaddr_iso *src, *dst;
196 	int clnp_len, ce_bit;
197 {
198 	int s = splnet();
199 	unsigned long sum, lindex, findex;
200 	register struct tcpiphdr *ti;
201 	register struct inpcb *inp;
202 	struct mbuf *om;
203 	int len, tlen, off;
204 	register struct tcpcb *tp = 0;
205 	int tiflags;
206 	struct socket *so;
207 	int todrop, acked, ourfinisacked, needoutput = 0;
208 	short ostate;
209 	struct in_addr laddr;
210 	int dropsocket = 0, iss = 0;
211 
212 	if ((m->m_flags & M_PKTHDR) == 0) {
213 		om = m_gethdr(M_DONTWAIT, MT_DATA);
214 		if (om == 0)
215 			goto drop;
216 		om->m_next = m;
217 	} else
218 		om = m;
219 	for (len = 0; m; m = m->m_next)
220 		len += m->m_len;
221 	m = om;
222 	om = 0;
223 	m->m_pkthdr.len = len;
224 	/*
225 	 * Do some housekeeping looking up CLNP addresses.
226 	 * If we are out of space might as well drop the packet now.
227 	 */
228 	tcpstat.tcps_rcvtotal++;
229 	lindex = tuba_lookup(&dst->siso_addr, M_DONTWAIT);
230 	findex = tuba_lookup(&dst->siso_addr, M_DONTWAIT);
231 	if (lindex == 0 || findex == 0)
232 		goto drop;
233 	/*
234 	 * Get CLNP and TCP header together in first mbuf.
235 	 * CLNP gave us an mbuf chain WITH the clnp header pulled up,
236 	 * and the length of the clnp header.
237 	 */
238 	len = clnp_len + sizeof(struct tcphdr);
239 	if (m->m_len < len) {
240 		if ((m = m_pullup(m, len)) == 0) {
241 			tcpstat.tcps_rcvshort++;
242 			return;
243 		}
244 	}
245 	/*
246 	 * Calculate checksum of extended TCP header and data,
247 	 * by adjusting the checksum for missing parts of the header.
248 	 */
249 	m->m_data += clnp_len;
250 	m->m_len -= clnp_len;
251 	tlen = m->m_pkthdr.len -= clnp_len;
252 	REDUCE(sum, tuba_table[findex]->tc_sum_in + htons((u_short)tlen)
253 		+ htons((u_short)ISOPROTO_TCP)
254 		+ tuba_table[lindex]->tc_sum_in + in_cksum(m, tlen));
255 	if (sum) {
256 		tcpstat.tcps_rcvbadsum++;
257 		tuba_badcksum();
258 		goto drop;
259 	}
260 	m->m_data -= sizeof(struct ip);
261 	m->m_len += sizeof(struct ip);
262 	m->m_pkthdr.len += sizeof(struct ip);
263 	/*
264 	 * The reassembly code assumes it will be overwriting a useless
265 	 * part of the packet, which is why we need to have it point
266 	 * into the packet itself.
267 	 *
268 	 * Check to see if the data is properly alligned
269 	 * so that we can save copying the tcp header.
270 	 * This code knows way too much about the structure of mbufs!
271 	 */
272 	off = ((sizeof (long) - 1) & ((m->m_flags & M_EXT) ?
273 		(m->m_data - m->m_ext.ext_buf) :  (m->m_data - m->m_pktdat)));
274 	if (off) {
275 		struct mbuf *m0 = m_gethdr(M_DONTWAIT, MT_DATA);
276 		if (m0 == 0) {
277 			goto drop;
278 		}
279 		bcopy(mtod(m, caddr_t) + sizeof(struct ip),
280 		      mtod(m0, caddr_t) + sizeof(struct ip),
281 		      sizeof(struct tcphdr));
282 		m->m_data += sizeof(struct tcpiphdr);
283 		m0->m_next = m;
284 		m0->m_pkthdr = m->m_pkthdr;
285 		m0->m_flags = m->m_flags & M_COPYFLAGS;
286 		m0->m_len = sizeof(struct tcpiphdr);
287 		m = m0;
288 	}
289 	ti = mtod(m, struct tcpiphdr *);
290 	ti->ti_src.s_addr = findex;
291 	ti->ti_dst.s_addr = lindex;
292 	/*
293 	 * Now include the rest of TCP input
294 	 */
295 #define TUBA_INCLUDE
296 #define in_pcbconnect	tuba_pcbconnect
297 
298 #include <netinet/tcp_input.c>
299 }
300