Commit | Line | Data |
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13e2480b | 1 | /* tcp_subr.c 4.41 83/05/12 */ |
ecaa4e6f BJ |
2 | |
3 | #include "../h/param.h" | |
4 | #include "../h/systm.h" | |
5 | #include "../h/mbuf.h" | |
6 | #include "../h/socket.h" | |
7 | #include "../h/socketvar.h" | |
8 | #include "../h/protosw.h" | |
f4d55810 SL |
9 | #include "../h/errno.h" |
10 | ||
c124e997 | 11 | #include "../net/route.h" |
f4d55810 SL |
12 | #include "../net/if.h" |
13 | ||
14 | #include "../netinet/in.h" | |
fcfe450e BJ |
15 | #include "../netinet/in_pcb.h" |
16 | #include "../netinet/in_systm.h" | |
fcfe450e BJ |
17 | #include "../netinet/ip.h" |
18 | #include "../netinet/ip_var.h" | |
19 | #include "../netinet/ip_icmp.h" | |
20 | #include "../netinet/tcp.h" | |
21 | #include "../netinet/tcp_fsm.h" | |
22 | #include "../netinet/tcp_seq.h" | |
23 | #include "../netinet/tcp_timer.h" | |
24 | #include "../netinet/tcp_var.h" | |
25 | #include "../netinet/tcpip.h" | |
ecaa4e6f BJ |
26 | |
27 | /* | |
28 | * Tcp initialization | |
29 | */ | |
30 | tcp_init() | |
31 | { | |
32 | ||
33 | tcp_iss = 1; /* wrong */ | |
34 | tcb.inp_next = tcb.inp_prev = &tcb; | |
405c9168 BJ |
35 | tcp_alpha = TCP_ALPHA; |
36 | tcp_beta = TCP_BETA; | |
ecaa4e6f BJ |
37 | } |
38 | ||
39 | /* | |
40 | * Create template to be used to send tcp packets on a connection. | |
41 | * Call after host entry created, allocates an mbuf and fills | |
42 | * in a skeletal tcp/ip header, minimizing the amount of work | |
43 | * necessary when the connection is used. | |
44 | */ | |
45 | struct tcpiphdr * | |
46 | tcp_template(tp) | |
47 | struct tcpcb *tp; | |
48 | { | |
49 | register struct inpcb *inp = tp->t_inpcb; | |
50 | register struct mbuf *m; | |
51 | register struct tcpiphdr *n; | |
52 | ||
cce93e4b | 53 | m = m_get(M_WAIT, MT_HEADER); |
5cdc4d65 | 54 | if (m == NULL) |
ecaa4e6f BJ |
55 | return (0); |
56 | m->m_off = MMAXOFF - sizeof (struct tcpiphdr); | |
57 | m->m_len = sizeof (struct tcpiphdr); | |
58 | n = mtod(m, struct tcpiphdr *); | |
59 | n->ti_next = n->ti_prev = 0; | |
60 | n->ti_x1 = 0; | |
61 | n->ti_pr = IPPROTO_TCP; | |
62 | n->ti_len = htons(sizeof (struct tcpiphdr) - sizeof (struct ip)); | |
63 | n->ti_src = inp->inp_laddr; | |
64 | n->ti_dst = inp->inp_faddr; | |
65 | n->ti_sport = inp->inp_lport; | |
66 | n->ti_dport = inp->inp_fport; | |
67 | n->ti_seq = 0; | |
0974b45c | 68 | n->ti_ack = 0; |
ecaa4e6f BJ |
69 | n->ti_x2 = 0; |
70 | n->ti_off = 5; | |
71 | n->ti_flags = 0; | |
72 | n->ti_win = 0; | |
73 | n->ti_sum = 0; | |
74 | n->ti_urp = 0; | |
75 | return (n); | |
76 | } | |
77 | ||
78 | /* | |
405c9168 BJ |
79 | * Send a single message to the TCP at address specified by |
80 | * the given TCP/IP header. If flags==0, then we make a copy | |
81 | * of the tcpiphdr at ti and send directly to the addressed host. | |
82 | * This is used to force keep alive messages out using the TCP | |
83 | * template for a connection tp->t_template. If flags are given | |
84 | * then we send a message back to the TCP which originated the | |
85 | * segment ti, and discard the mbuf containing it and any other | |
86 | * attached mbufs. | |
87 | * | |
88 | * In any case the ack and sequence number of the transmitted | |
89 | * segment are as specified by the parameters. | |
ecaa4e6f | 90 | */ |
8e65fd66 BJ |
91 | tcp_respond(tp, ti, ack, seq, flags) |
92 | struct tcpcb *tp; | |
ecaa4e6f | 93 | register struct tcpiphdr *ti; |
0974b45c | 94 | tcp_seq ack, seq; |
ecaa4e6f BJ |
95 | int flags; |
96 | { | |
405c9168 | 97 | struct mbuf *m; |
1e977657 | 98 | int win = 0, tlen; |
c124e997 | 99 | struct route *ro = 0; |
ecaa4e6f | 100 | |
c124e997 | 101 | if (tp) { |
8e65fd66 | 102 | win = sbspace(&tp->t_inpcb->inp_socket->so_rcv); |
c124e997 SL |
103 | ro = &tp->t_inpcb->inp_route; |
104 | } | |
405c9168 | 105 | if (flags == 0) { |
cce93e4b | 106 | m = m_get(M_DONTWAIT, MT_HEADER); |
5cdc4d65 | 107 | if (m == NULL) |
405c9168 | 108 | return; |
1e977657 | 109 | m->m_len = sizeof (struct tcpiphdr) + 1; |
405c9168 BJ |
110 | *mtod(m, struct tcpiphdr *) = *ti; |
111 | ti = mtod(m, struct tcpiphdr *); | |
112 | flags = TH_ACK; | |
1e977657 | 113 | tlen = 1; |
405c9168 | 114 | } else { |
4aed14e3 | 115 | m = dtom(ti); |
405c9168 BJ |
116 | m_freem(m->m_next); |
117 | m->m_next = 0; | |
1acff8ec | 118 | m->m_off = (int)ti - (int)m; |
405c9168 | 119 | m->m_len = sizeof (struct tcpiphdr); |
0974b45c | 120 | #define xchg(a,b,type) { type t; t=a; a=b; b=t; } |
405c9168 BJ |
121 | xchg(ti->ti_dst.s_addr, ti->ti_src.s_addr, u_long); |
122 | xchg(ti->ti_dport, ti->ti_sport, u_short); | |
ecaa4e6f | 123 | #undef xchg |
1e977657 | 124 | tlen = 0; |
405c9168 | 125 | } |
0974b45c BJ |
126 | ti->ti_next = ti->ti_prev = 0; |
127 | ti->ti_x1 = 0; | |
af8f6a21 | 128 | ti->ti_len = htons((u_short)(sizeof (struct tcphdr) + tlen)); |
2c48b3f8 BJ |
129 | ti->ti_seq = htonl(seq); |
130 | ti->ti_ack = htonl(ack); | |
0974b45c BJ |
131 | ti->ti_x2 = 0; |
132 | ti->ti_off = sizeof (struct tcphdr) >> 2; | |
ecaa4e6f | 133 | ti->ti_flags = flags; |
af8f6a21 | 134 | ti->ti_win = htons((u_short)win); |
8e65fd66 | 135 | ti->ti_urp = 0; |
f3cdd721 | 136 | ti->ti_sum = in_cksum(m, sizeof (struct tcpiphdr) + tlen); |
1e977657 | 137 | ((struct ip *)ti)->ip_len = sizeof (struct tcpiphdr) + tlen; |
0974b45c | 138 | ((struct ip *)ti)->ip_ttl = TCP_TTL; |
c124e997 | 139 | (void) ip_output(m, (struct mbuf *)0, ro, 0); |
ecaa4e6f | 140 | } |
a6503abf | 141 | |
0974b45c BJ |
142 | /* |
143 | * Create a new TCP control block, making an | |
144 | * empty reassembly queue and hooking it to the argument | |
145 | * protocol control block. | |
146 | */ | |
a6503abf BJ |
147 | struct tcpcb * |
148 | tcp_newtcpcb(inp) | |
149 | struct inpcb *inp; | |
150 | { | |
cce93e4b | 151 | struct mbuf *m = m_getclr(M_DONTWAIT, MT_PCB); |
a6503abf | 152 | register struct tcpcb *tp; |
a6503abf | 153 | |
5cdc4d65 SL |
154 | if (m == NULL) |
155 | return ((struct tcpcb *)0); | |
a6503abf | 156 | tp = mtod(m, struct tcpcb *); |
a6503abf | 157 | tp->seg_next = tp->seg_prev = (struct tcpiphdr *)tp; |
af058d1e SL |
158 | /* |
159 | * If the default maximum IP packet size is 576 bytes | |
160 | * and a standard IP header is 20 bytes, with a TCP | |
161 | * header of 20 bytes plus the options necessary to | |
162 | * upgrade it to something higher, then initialize the | |
163 | * maximum segment size to 576 - (20 + 20 + 8 + slop). | |
164 | */ | |
165 | tp->t_maxseg = 512; /* satisfy the rest of the world */ | |
3e60e1e6 | 166 | tp->t_flags = 0; /* sends options! */ |
a6503abf BJ |
167 | tp->t_inpcb = inp; |
168 | inp->inp_ppcb = (caddr_t)tp; | |
169 | return (tp); | |
170 | } | |
171 | ||
0974b45c BJ |
172 | /* |
173 | * Drop a TCP connection, reporting | |
174 | * the specified error. If connection is synchronized, | |
175 | * then send a RST to peer. | |
176 | */ | |
0e3936fa | 177 | struct tcpcb * |
a6503abf | 178 | tcp_drop(tp, errno) |
0e3936fa | 179 | register struct tcpcb *tp; |
a6503abf BJ |
180 | int errno; |
181 | { | |
182 | struct socket *so = tp->t_inpcb->inp_socket; | |
183 | ||
d3504cc0 | 184 | if (TCPS_HAVERCVDSYN(tp->t_state)) { |
a6503abf | 185 | tp->t_state = TCPS_CLOSED; |
39d536e6 | 186 | (void) tcp_output(tp); |
a6503abf BJ |
187 | } |
188 | so->so_error = errno; | |
0e3936fa | 189 | return (tcp_close(tp)); |
a6503abf BJ |
190 | } |
191 | ||
72e4f44e SL |
192 | tcp_abort(inp) |
193 | struct inpcb *inp; | |
194 | { | |
a1edc12b | 195 | |
0e3936fa | 196 | (void) tcp_close((struct tcpcb *)inp->inp_ppcb); |
72e4f44e SL |
197 | } |
198 | ||
0974b45c BJ |
199 | /* |
200 | * Close a TCP control block: | |
201 | * discard all space held by the tcp | |
202 | * discard internet protocol block | |
203 | * wake up any sleepers | |
204 | */ | |
0e3936fa | 205 | struct tcpcb * |
a6503abf BJ |
206 | tcp_close(tp) |
207 | register struct tcpcb *tp; | |
208 | { | |
209 | register struct tcpiphdr *t; | |
364801f5 BJ |
210 | struct inpcb *inp = tp->t_inpcb; |
211 | struct socket *so = inp->inp_socket; | |
13e2480b | 212 | register struct mbuf *m; |
a6503abf | 213 | |
a6503abf | 214 | t = tp->seg_next; |
13e2480b SL |
215 | while (t != (struct tcpiphdr *)tp) { |
216 | t = (struct tcpiphdr *)t->ti_next; | |
217 | m = dtom(t->ti_prev); | |
218 | remque(t->ti_prev); | |
219 | m_freem(m); | |
220 | } | |
0974b45c | 221 | if (tp->t_template) |
a6503abf | 222 | (void) m_free(dtom(tp->t_template)); |
0974b45c BJ |
223 | if (tp->t_tcpopt) |
224 | (void) m_free(dtom(tp->t_tcpopt)); | |
225 | if (tp->t_ipopt) | |
226 | (void) m_free(dtom(tp->t_ipopt)); | |
a6503abf | 227 | (void) m_free(dtom(tp)); |
364801f5 | 228 | inp->inp_ppcb = 0; |
4aed14e3 | 229 | soisdisconnected(so); |
86676257 | 230 | in_pcbdetach(inp); |
0e3936fa | 231 | return ((struct tcpcb *)0); |
a6503abf BJ |
232 | } |
233 | ||
a6503abf BJ |
234 | tcp_drain() |
235 | { | |
a6503abf | 236 | |
a6503abf BJ |
237 | } |
238 | ||
72e4f44e SL |
239 | tcp_ctlinput(cmd, arg) |
240 | int cmd; | |
241 | caddr_t arg; | |
a6503abf | 242 | { |
39674d5f SL |
243 | struct in_addr *sin; |
244 | extern u_char inetctlerrmap[]; | |
39674d5f SL |
245 | |
246 | if (cmd < 0 || cmd > PRC_NCMDS) | |
247 | return; | |
248 | switch (cmd) { | |
249 | ||
250 | case PRC_ROUTEDEAD: | |
251 | break; | |
252 | ||
253 | case PRC_QUENCH: | |
254 | break; | |
255 | ||
256 | /* these are handled by ip */ | |
257 | case PRC_IFDOWN: | |
258 | case PRC_HOSTDEAD: | |
259 | case PRC_HOSTUNREACH: | |
260 | break; | |
261 | ||
262 | default: | |
263 | sin = &((struct icmp *)arg)->icmp_ip.ip_dst; | |
a1edc12b | 264 | in_pcbnotify(&tcb, sin, (int)inetctlerrmap[cmd], tcp_abort); |
39674d5f | 265 | } |
a6503abf | 266 | } |