Commit | Line | Data |
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88a7a62a | 1 | /* uipc_socket2.c 4.37 83/05/27 */ |
681ebb17 BJ |
2 | |
3 | #include "../h/param.h" | |
4 | #include "../h/systm.h" | |
5 | #include "../h/dir.h" | |
6 | #include "../h/user.h" | |
7 | #include "../h/proc.h" | |
8 | #include "../h/file.h" | |
9 | #include "../h/inode.h" | |
10 | #include "../h/buf.h" | |
11 | #include "../h/mbuf.h" | |
681ebb17 BJ |
12 | #include "../h/protosw.h" |
13 | #include "../h/socket.h" | |
14 | #include "../h/socketvar.h" | |
681ebb17 BJ |
15 | |
16 | /* | |
17 | * Primitive routines for operating on sockets and socket buffers | |
18 | */ | |
19 | ||
20 | /* | |
21 | * Procedures to manipulate state flags of socket | |
2deddea9 BJ |
22 | * and do appropriate wakeups. Normal sequence from the |
23 | * active (originating) side is that soisconnecting() is | |
24 | * called during processing of connect() call, | |
4c078bb2 BJ |
25 | * resulting in an eventual call to soisconnected() if/when the |
26 | * connection is established. When the connection is torn down | |
27 | * soisdisconnecting() is called during processing of disconnect() call, | |
28 | * and soisdisconnected() is called when the connection to the peer | |
29 | * is totally severed. The semantics of these routines are such that | |
30 | * connectionless protocols can call soisconnected() and soisdisconnected() | |
31 | * only, bypassing the in-progress calls when setting up a ``connection'' | |
32 | * takes no time. | |
33 | * | |
88a7a62a SL |
34 | * From the passive side, a socket is created with |
35 | * two queues of sockets: so_q0 for connections in progress | |
2deddea9 BJ |
36 | * and so_q for connections already made and awaiting user acceptance. |
37 | * As a protocol is preparing incoming connections, it creates a socket | |
38 | * structure queued on so_q0 by calling sonewconn(). When the connection | |
39 | * is established, soisconnected() is called, and transfers the | |
40 | * socket structure to so_q, making it available to accept(). | |
41 | * | |
88a7a62a | 42 | * If a socket is closed with sockets on either |
2deddea9 BJ |
43 | * so_q0 or so_q, these sockets are dropped. |
44 | * | |
88a7a62a | 45 | * If higher level protocols are implemented in |
4c078bb2 | 46 | * the kernel, the wakeups done here will sometimes |
88a7a62a | 47 | * cause software-interrupt process scheduling. |
681ebb17 | 48 | */ |
4c078bb2 | 49 | |
681ebb17 | 50 | soisconnecting(so) |
88a7a62a | 51 | register struct socket *so; |
681ebb17 BJ |
52 | { |
53 | ||
54 | so->so_state &= ~(SS_ISCONNECTED|SS_ISDISCONNECTING); | |
55 | so->so_state |= SS_ISCONNECTING; | |
56 | wakeup((caddr_t)&so->so_timeo); | |
57 | } | |
58 | ||
59 | soisconnected(so) | |
88a7a62a | 60 | register struct socket *so; |
681ebb17 | 61 | { |
2deddea9 | 62 | register struct socket *head = so->so_head; |
681ebb17 | 63 | |
2deddea9 BJ |
64 | if (head) { |
65 | if (soqremque(so, 0) == 0) | |
66 | panic("soisconnected"); | |
67 | soqinsque(head, so, 1); | |
ab303321 | 68 | sorwakeup(head); |
88a7a62a | 69 | wakeup((caddr_t)&head->so_timeo); |
2deddea9 | 70 | } |
681ebb17 BJ |
71 | so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING); |
72 | so->so_state |= SS_ISCONNECTED; | |
73 | wakeup((caddr_t)&so->so_timeo); | |
f957a49a BJ |
74 | sorwakeup(so); |
75 | sowwakeup(so); | |
681ebb17 BJ |
76 | } |
77 | ||
78 | soisdisconnecting(so) | |
88a7a62a | 79 | register struct socket *so; |
681ebb17 BJ |
80 | { |
81 | ||
72857acf | 82 | so->so_state &= ~SS_ISCONNECTING; |
681ebb17 BJ |
83 | so->so_state |= (SS_ISDISCONNECTING|SS_CANTRCVMORE|SS_CANTSENDMORE); |
84 | wakeup((caddr_t)&so->so_timeo); | |
4c078bb2 | 85 | sowwakeup(so); |
b454c3ea | 86 | sorwakeup(so); |
681ebb17 BJ |
87 | } |
88 | ||
89 | soisdisconnected(so) | |
88a7a62a | 90 | register struct socket *so; |
681ebb17 BJ |
91 | { |
92 | ||
93 | so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING); | |
94 | so->so_state |= (SS_CANTRCVMORE|SS_CANTSENDMORE); | |
95 | wakeup((caddr_t)&so->so_timeo); | |
96 | sowwakeup(so); | |
97 | sorwakeup(so); | |
98 | } | |
99 | ||
2deddea9 BJ |
100 | /* |
101 | * When an attempt at a new connection is noted on a socket | |
102 | * which accepts connections, sonewconn is called. If the | |
103 | * connection is possible (subject to space constraints, etc.) | |
104 | * then we allocate a new structure, propoerly linked into the | |
105 | * data structure of the original socket, and return this. | |
106 | */ | |
107 | struct socket * | |
108 | sonewconn(head) | |
109 | register struct socket *head; | |
110 | { | |
111 | register struct socket *so; | |
88a7a62a | 112 | register struct mbuf *m; |
2deddea9 BJ |
113 | |
114 | if (head->so_qlen + head->so_q0len > 3 * head->so_qlimit / 2) | |
115 | goto bad; | |
cce93e4b | 116 | m = m_getclr(M_DONTWAIT, MT_SOCKET); |
5fe6f9d1 | 117 | if (m == NULL) |
2deddea9 BJ |
118 | goto bad; |
119 | so = mtod(m, struct socket *); | |
120 | so->so_type = head->so_type; | |
121 | so->so_options = head->so_options &~ SO_ACCEPTCONN; | |
122 | so->so_linger = head->so_linger; | |
f7428e88 | 123 | so->so_state = head->so_state | SS_NOFDREF; |
2deddea9 BJ |
124 | so->so_proto = head->so_proto; |
125 | so->so_timeo = head->so_timeo; | |
126 | so->so_pgrp = head->so_pgrp; | |
127 | soqinsque(head, so, 0); | |
88a7a62a SL |
128 | if ((*so->so_proto->pr_usrreq)(so, PRU_ATTACH, |
129 | (struct mbuf *)0, (struct mbuf *)0, (struct mbuf *)0)) { | |
2deddea9 | 130 | (void) soqremque(so, 0); |
30c36259 | 131 | (void) m_free(m); |
2deddea9 BJ |
132 | goto bad; |
133 | } | |
134 | return (so); | |
135 | bad: | |
136 | return ((struct socket *)0); | |
137 | } | |
138 | ||
139 | soqinsque(head, so, q) | |
140 | register struct socket *head, *so; | |
141 | int q; | |
142 | { | |
143 | ||
144 | so->so_head = head; | |
145 | if (q == 0) { | |
146 | head->so_q0len++; | |
147 | so->so_q0 = head->so_q0; | |
148 | head->so_q0 = so; | |
149 | } else { | |
150 | head->so_qlen++; | |
151 | so->so_q = head->so_q; | |
152 | head->so_q = so; | |
153 | } | |
154 | } | |
155 | ||
156 | soqremque(so, q) | |
157 | register struct socket *so; | |
158 | int q; | |
159 | { | |
160 | register struct socket *head, *prev, *next; | |
161 | ||
162 | head = so->so_head; | |
163 | prev = head; | |
164 | for (;;) { | |
165 | next = q ? prev->so_q : prev->so_q0; | |
166 | if (next == so) | |
167 | break; | |
168 | if (next == head) | |
169 | return (0); | |
170 | prev = next; | |
171 | } | |
172 | if (q == 0) { | |
173 | prev->so_q0 = next->so_q0; | |
174 | head->so_q0len--; | |
175 | } else { | |
176 | prev->so_q = next->so_q; | |
177 | head->so_qlen--; | |
178 | } | |
179 | next->so_q0 = next->so_q = 0; | |
180 | next->so_head = 0; | |
181 | return (1); | |
182 | } | |
183 | ||
4c078bb2 BJ |
184 | /* |
185 | * Socantsendmore indicates that no more data will be sent on the | |
186 | * socket; it would normally be applied to a socket when the user | |
187 | * informs the system that no more data is to be sent, by the protocol | |
188 | * code (in case PRU_SHUTDOWN). Socantrcvmore indicates that no more data | |
189 | * will be received, and will normally be applied to the socket by a | |
190 | * protocol when it detects that the peer will send no more data. | |
191 | * Data queued for reading in the socket may yet be read. | |
192 | */ | |
193 | ||
ae921915 BJ |
194 | socantsendmore(so) |
195 | struct socket *so; | |
196 | { | |
197 | ||
198 | so->so_state |= SS_CANTSENDMORE; | |
199 | sowwakeup(so); | |
200 | } | |
201 | ||
202 | socantrcvmore(so) | |
203 | struct socket *so; | |
204 | { | |
205 | ||
206 | so->so_state |= SS_CANTRCVMORE; | |
207 | sorwakeup(so); | |
208 | } | |
209 | ||
681ebb17 | 210 | /* |
4c078bb2 BJ |
211 | * Socket select/wakeup routines. |
212 | */ | |
213 | ||
681ebb17 BJ |
214 | /* |
215 | * Queue a process for a select on a socket buffer. | |
216 | */ | |
217 | sbselqueue(sb) | |
218 | struct sockbuf *sb; | |
219 | { | |
220 | register struct proc *p; | |
221 | ||
ae921915 | 222 | if ((p = sb->sb_sel) && p->p_wchan == (caddr_t)&selwait) |
681ebb17 BJ |
223 | sb->sb_flags |= SB_COLL; |
224 | else | |
225 | sb->sb_sel = u.u_procp; | |
226 | } | |
227 | ||
ae921915 BJ |
228 | /* |
229 | * Wait for data to arrive at/drain from a socket buffer. | |
230 | */ | |
231 | sbwait(sb) | |
232 | struct sockbuf *sb; | |
233 | { | |
234 | ||
235 | sb->sb_flags |= SB_WAIT; | |
236 | sleep((caddr_t)&sb->sb_cc, PZERO+1); | |
237 | } | |
238 | ||
681ebb17 BJ |
239 | /* |
240 | * Wakeup processes waiting on a socket buffer. | |
241 | */ | |
242 | sbwakeup(sb) | |
88a7a62a | 243 | register struct sockbuf *sb; |
681ebb17 BJ |
244 | { |
245 | ||
246 | if (sb->sb_sel) { | |
247 | selwakeup(sb->sb_sel, sb->sb_flags & SB_COLL); | |
248 | sb->sb_sel = 0; | |
249 | sb->sb_flags &= ~SB_COLL; | |
250 | } | |
251 | if (sb->sb_flags & SB_WAIT) { | |
252 | sb->sb_flags &= ~SB_WAIT; | |
388ca8bd | 253 | wakeup((caddr_t)&sb->sb_cc); |
681ebb17 BJ |
254 | } |
255 | } | |
256 | ||
4c078bb2 BJ |
257 | /* |
258 | * Socket buffer (struct sockbuf) utility routines. | |
259 | * | |
260 | * Each socket contains two socket buffers: one for sending data and | |
261 | * one for receiving data. Each buffer contains a queue of mbufs, | |
262 | * information about the number of mbufs and amount of data in the | |
263 | * queue, and other fields allowing select() statements and notification | |
264 | * on data availability to be implemented. | |
265 | * | |
266 | * Before using a new socket structure it is first necessary to reserve | |
267 | * buffer space to the socket, by calling sbreserve. This commits | |
268 | * some of the available buffer space in the system buffer pool for the | |
269 | * socket. The space should be released by calling sbrelease when the | |
270 | * socket is destroyed. | |
271 | * | |
272 | * The routine sbappend() is normally called to append new mbufs | |
273 | * to a socket buffer, after checking that adequate space is available | |
274 | * comparing the function spspace() with the amount of data to be added. | |
275 | * Data is normally removed from a socket buffer in a protocol by | |
276 | * first calling m_copy on the socket buffer mbuf chain and sending this | |
277 | * to a peer, and then removing the data from the socket buffer with | |
278 | * sbdrop when the data is acknowledged by the peer (or immediately | |
b454c3ea | 279 | * in the case of unreliable protocols.) |
4c078bb2 BJ |
280 | * |
281 | * Protocols which do not require connections place both source address | |
282 | * and data information in socket buffer queues. The source addresses | |
283 | * are stored in single mbufs after each data item, and are easily found | |
284 | * as the data items are all marked with end of record markers. The | |
285 | * sbappendaddr() routine stores a datum and associated address in | |
286 | * a socket buffer. Note that, unlike sbappend(), this routine checks | |
287 | * for the caller that there will be enough space to store the data. | |
288 | * It fails if there is not enough space, or if it cannot find | |
289 | * a mbuf to store the address in. | |
290 | * | |
291 | * The higher-level routines sosend and soreceive (in socket.c) | |
b454c3ea | 292 | * also add data to, and remove data from socket buffers repectively. |
4c078bb2 BJ |
293 | */ |
294 | ||
0e18ec4a | 295 | soreserve(so, sndcc, rcvcc) |
88a7a62a | 296 | register struct socket *so; |
0e18ec4a BJ |
297 | int sndcc, rcvcc; |
298 | { | |
299 | ||
300 | if (sbreserve(&so->so_snd, sndcc) == 0) | |
301 | goto bad; | |
302 | if (sbreserve(&so->so_rcv, rcvcc) == 0) | |
303 | goto bad2; | |
304 | return (0); | |
305 | bad2: | |
306 | sbrelease(&so->so_snd); | |
307 | bad: | |
308 | return (ENOBUFS); | |
309 | } | |
310 | ||
681ebb17 BJ |
311 | /* |
312 | * Allot mbufs to a sockbuf. | |
313 | */ | |
314 | sbreserve(sb, cc) | |
315 | struct sockbuf *sb; | |
316 | { | |
317 | ||
de48daf3 | 318 | /* someday maybe this routine will fail... */ |
d028a086 | 319 | sb->sb_hiwat = cc; |
88a7a62a SL |
320 | /* * 2 implies names can be no more than 1 mbuf each */ |
321 | sb->sb_mbmax = cc<<1; | |
ae921915 | 322 | return (1); |
681ebb17 BJ |
323 | } |
324 | ||
325 | /* | |
326 | * Free mbufs held by a socket, and reserved mbuf space. | |
327 | */ | |
328 | sbrelease(sb) | |
329 | struct sockbuf *sb; | |
330 | { | |
331 | ||
332 | sbflush(sb); | |
d028a086 | 333 | sb->sb_hiwat = sb->sb_mbmax = 0; |
681ebb17 BJ |
334 | } |
335 | ||
336 | /* | |
337 | * Routines to add (at the end) and remove (from the beginning) | |
338 | * data from a mbuf queue. | |
339 | */ | |
340 | ||
341 | /* | |
342 | * Append mbuf queue m to sockbuf sb. | |
343 | */ | |
344 | sbappend(sb, m) | |
345 | register struct mbuf *m; | |
346 | register struct sockbuf *sb; | |
347 | { | |
e495e1cc | 348 | register struct mbuf *n; |
681ebb17 | 349 | |
e495e1cc BJ |
350 | n = sb->sb_mb; |
351 | if (n) | |
352 | while (n->m_next) | |
353 | n = n->m_next; | |
681ebb17 | 354 | while (m) { |
a73ab5ae | 355 | if (m->m_len == 0 && (int)m->m_act == 0) { |
c64d826c | 356 | m = m_free(m); |
a73ab5ae BJ |
357 | continue; |
358 | } | |
681ebb17 BJ |
359 | if (n && n->m_off <= MMAXOFF && m->m_off <= MMAXOFF && |
360 | (int)n->m_act == 0 && (int)m->m_act == 0 && | |
76a6e254 BJ |
361 | (n->m_off + n->m_len + m->m_len) <= MMAXOFF) { |
362 | bcopy(mtod(m, caddr_t), mtod(n, caddr_t) + n->m_len, | |
ae921915 | 363 | (unsigned)m->m_len); |
681ebb17 BJ |
364 | n->m_len += m->m_len; |
365 | sb->sb_cc += m->m_len; | |
366 | m = m_free(m); | |
367 | continue; | |
368 | } | |
369 | sballoc(sb, m); | |
e495e1cc BJ |
370 | if (n == 0) |
371 | sb->sb_mb = m; | |
372 | else | |
373 | n->m_next = m; | |
681ebb17 | 374 | n = m; |
681ebb17 | 375 | m = m->m_next; |
e495e1cc | 376 | n->m_next = 0; |
681ebb17 BJ |
377 | } |
378 | } | |
379 | ||
4c078bb2 BJ |
380 | /* |
381 | * Append data and address. | |
382 | * Return 0 if no space in sockbuf or if | |
383 | * can't get mbuf to stuff address in. | |
384 | */ | |
88a7a62a | 385 | sbappendaddr(sb, asa, m0, rights0) |
2b4b57cd BJ |
386 | struct sockbuf *sb; |
387 | struct sockaddr *asa; | |
88a7a62a | 388 | struct mbuf *m0, *rights0; |
2b4b57cd | 389 | { |
2b4b57cd BJ |
390 | register struct mbuf *m; |
391 | register int len = sizeof (struct sockaddr); | |
88a7a62a | 392 | register struct mbuf *rights; |
2b4b57cd | 393 | |
88a7a62a SL |
394 | if (rights0) |
395 | len += rights0->m_len; | |
76a6e254 BJ |
396 | m = m0; |
397 | if (m == 0) | |
398 | panic("sbappendaddr"); | |
399 | for (;;) { | |
2b4b57cd | 400 | len += m->m_len; |
76a6e254 BJ |
401 | if (m->m_next == 0) { |
402 | m->m_act = (struct mbuf *)1; | |
403 | break; | |
404 | } | |
405 | m = m->m_next; | |
406 | } | |
509e40dd | 407 | if (len > sbspace(sb)) |
2b4b57cd | 408 | return (0); |
cce93e4b | 409 | m = m_get(M_DONTWAIT, MT_SONAME); |
88a7a62a | 410 | if (m == NULL) |
2b4b57cd | 411 | return (0); |
2b4b57cd | 412 | m->m_len = sizeof (struct sockaddr); |
2b4b57cd | 413 | m->m_act = (struct mbuf *)1; |
88a7a62a SL |
414 | *mtod(m, struct sockaddr *) = *asa; |
415 | if (rights0 == 0 || rights0->m_len == 0) { | |
416 | rights = m_get(M_DONTWAIT, MT_SONAME); | |
417 | if (rights) | |
418 | rights->m_len = 0; | |
419 | } else | |
420 | rights = m_copy(rights0, 0, rights0->m_len); | |
421 | if (rights == 0) { | |
422 | m_freem(m); | |
423 | return (0); | |
424 | } | |
425 | rights->m_act = (struct mbuf *)1; | |
426 | m->m_next = rights; | |
427 | rights->m_next = m0; | |
2b4b57cd | 428 | sbappend(sb, m); |
2b4b57cd BJ |
429 | return (1); |
430 | } | |
431 | ||
681ebb17 BJ |
432 | /* |
433 | * Free all mbufs on a sockbuf mbuf chain. | |
434 | * Check that resource allocations return to 0. | |
435 | */ | |
436 | sbflush(sb) | |
88a7a62a | 437 | register struct sockbuf *sb; |
681ebb17 BJ |
438 | { |
439 | ||
440 | if (sb->sb_flags & SB_LOCK) | |
441 | panic("sbflush"); | |
a73ab5ae BJ |
442 | if (sb->sb_cc) |
443 | sbdrop(sb, sb->sb_cc); | |
681ebb17 BJ |
444 | if (sb->sb_cc || sb->sb_mbcnt || sb->sb_mb) |
445 | panic("sbflush 2"); | |
446 | } | |
447 | ||
448 | /* | |
449 | * Drop data from (the front of) a sockbuf chain. | |
450 | */ | |
451 | sbdrop(sb, len) | |
452 | register struct sockbuf *sb; | |
453 | register int len; | |
454 | { | |
455 | register struct mbuf *m = sb->sb_mb, *mn; | |
456 | ||
457 | while (len > 0) { | |
458 | if (m == 0) | |
459 | panic("sbdrop"); | |
b9f0d37f | 460 | if (m->m_len > len) { |
681ebb17 BJ |
461 | m->m_len -= len; |
462 | m->m_off += len; | |
463 | sb->sb_cc -= len; | |
464 | break; | |
465 | } | |
b9f0d37f BJ |
466 | len -= m->m_len; |
467 | sbfree(sb, m); | |
468 | MFREE(m, mn); | |
469 | m = mn; | |
681ebb17 BJ |
470 | } |
471 | sb->sb_mb = m; | |
472 | } |