1 /*
2  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
3  * Copyright (c) 1995-1999 by Internet Software Consortium
4  *
5  * Permission to use, copy, modify, and distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
15  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  */
17 
18 /* ev_connects.c - implement asynch connect/accept for the eventlib
19  * vix 16sep96 [initial]
20  */
21 
22 #include "port_before.h"
23 #include "fd_setsize.h"
24 
25 #include <sys/types.h>
26 #include <sys/socket.h>
27 #include <sys/ioctl.h>
28 
29 #include <unistd.h>
30 
31 #include <isc/eventlib.h>
32 #include <isc/assertions.h>
33 #include "eventlib_p.h"
34 
35 #include "port_after.h"
36 
37 /* Macros. */
38 
39 #define GETXXXNAME(f, s, sa, len) ( \
40 	(f((s), (&sa), (&len)) >= 0) ? 0 : \
41 		(errno != EAFNOSUPPORT && errno != EOPNOTSUPP) ? -1 : ( \
42 			memset(&(sa), 0, sizeof (sa)), \
43 			(len) = sizeof (sa), \
44 			(sa).sa_family = AF_UNIX, \
45 			0 \
46 		) \
47 	)
48 
49 /* Forward. */
50 
51 static void	listener(evContext ctx, void *uap, int fd, int evmask);
52 static void	connector(evContext ctx, void *uap, int fd, int evmask);
53 
54 /* Public. */
55 
56 int
evListen(evContext opaqueCtx,int fd,int maxconn,evConnFunc func,void * uap,evConnID * id)57 evListen(evContext opaqueCtx, int fd, int maxconn,
58 	 evConnFunc func, void *uap, evConnID *id)
59 {
60 	evContext_p *ctx = opaqueCtx.opaque;
61 	evConn *new;
62 	int mode;
63 
64 	OKNEW(new);
65 	new->flags = EV_CONN_LISTEN;
66 	OKFREE(mode = fcntl(fd, F_GETFL, NULL), new);	/*%< side effect: validate fd. */
67 	/*
68 	 * Remember the nonblocking status.  We assume that either evSelectFD
69 	 * has not been done to this fd, or that if it has then the caller
70 	 * will evCancelConn before they evDeselectFD.  If our assumptions
71 	 * are not met, then we might restore the old nonblocking status
72 	 * incorrectly.
73 	 */
74 	if ((mode & PORT_NONBLOCK) == 0) {
75 #ifdef USE_FIONBIO_IOCTL
76 		int on = 1;
77 		OKFREE(ioctl(fd, FIONBIO, (char *)&on), new);
78 #else
79 		OKFREE(fcntl(fd, F_SETFL, mode | PORT_NONBLOCK), new);
80 #endif
81 		new->flags |= EV_CONN_BLOCK;
82 	}
83 	OKFREE(listen(fd, maxconn), new);
84 	if (evSelectFD(opaqueCtx, fd, EV_READ, listener, new, &new->file) < 0){
85 		int save = errno;
86 
87 		FREE(new);
88 		errno = save;
89 		return (-1);
90 	}
91 	new->flags |= EV_CONN_SELECTED;
92 	new->func = func;
93 	new->uap = uap;
94 	new->fd = fd;
95 	if (ctx->conns != NULL)
96 		ctx->conns->prev = new;
97 	new->prev = NULL;
98 	new->next = ctx->conns;
99 	ctx->conns = new;
100 	if (id)
101 		id->opaque = new;
102 	return (0);
103 }
104 
105 int
evConnect(evContext opaqueCtx,int fd,const void * ra,int ralen,evConnFunc func,void * uap,evConnID * id)106 evConnect(evContext opaqueCtx, int fd, const void *ra, int ralen,
107 	  evConnFunc func, void *uap, evConnID *id)
108 {
109 	evContext_p *ctx = opaqueCtx.opaque;
110 	evConn *new;
111 
112 	OKNEW(new);
113 	new->flags = 0;
114 	/* Do the select() first to get the socket into nonblocking mode. */
115 	if (evSelectFD(opaqueCtx, fd, EV_MASK_ALL,
116 		       connector, new, &new->file) < 0) {
117 		int save = errno;
118 
119 		FREE(new);
120 		errno = save;
121 		return (-1);
122 	}
123 	new->flags |= EV_CONN_SELECTED;
124 	if (connect(fd, ra, ralen) < 0 &&
125 	    errno != EWOULDBLOCK &&
126 	    errno != EAGAIN &&
127 	    errno != EINPROGRESS) {
128 		int save = errno;
129 
130 		(void) evDeselectFD(opaqueCtx, new->file);
131 		FREE(new);
132 		errno = save;
133 		return (-1);
134 	}
135 	/* No error, or EWOULDBLOCK.  select() tells when it's ready. */
136 	new->func = func;
137 	new->uap = uap;
138 	new->fd = fd;
139 	if (ctx->conns != NULL)
140 		ctx->conns->prev = new;
141 	new->prev = NULL;
142 	new->next = ctx->conns;
143 	ctx->conns = new;
144 	if (id)
145 		id->opaque = new;
146 	return (0);
147 }
148 
149 int
evCancelConn(evContext opaqueCtx,evConnID id)150 evCancelConn(evContext opaqueCtx, evConnID id) {
151 	evContext_p *ctx = opaqueCtx.opaque;
152 	evConn *this = id.opaque;
153 	evAccept *acc, *nxtacc;
154 	int mode;
155 
156 	if ((this->flags & EV_CONN_SELECTED) != 0)
157 		(void) evDeselectFD(opaqueCtx, this->file);
158 	if ((this->flags & EV_CONN_BLOCK) != 0) {
159 		mode = fcntl(this->fd, F_GETFL, NULL);
160 		if (mode == -1) {
161 			if (errno != EBADF)
162 				return (-1);
163 		} else {
164 #ifdef USE_FIONBIO_IOCTL
165 			int off = 0;
166 			OK(ioctl(this->fd, FIONBIO, (char *)&off));
167 #else
168 			OK(fcntl(this->fd, F_SETFL, mode & ~PORT_NONBLOCK));
169 #endif
170 		}
171 	}
172 
173 	/* Unlink from ctx->conns. */
174 	if (this->prev != NULL)
175 		this->prev->next = this->next;
176 	else
177 		ctx->conns = this->next;
178 	if (this->next != NULL)
179 		this->next->prev = this->prev;
180 
181 	/*
182 	 * Remove `this' from the ctx->accepts list (zero or more times).
183 	 */
184 	for (acc = HEAD(ctx->accepts), nxtacc = NULL;
185 	     acc != NULL;
186 	     acc = nxtacc)
187 	{
188 		nxtacc = NEXT(acc, link);
189 		if (acc->conn == this) {
190 			UNLINK(ctx->accepts, acc, link);
191 			close(acc->fd);
192 			FREE(acc);
193 		}
194 	}
195 
196 	/* Wrap up and get out. */
197 	FREE(this);
198 	return (0);
199 }
200 
evHold(evContext opaqueCtx,evConnID id)201 int evHold(evContext opaqueCtx, evConnID id) {
202 	evConn *this = id.opaque;
203 
204 	if ((this->flags & EV_CONN_LISTEN) == 0) {
205 		errno = EINVAL;
206 		return (-1);
207 	}
208 	if ((this->flags & EV_CONN_SELECTED) == 0)
209 		return (0);
210 	this->flags &= ~EV_CONN_SELECTED;
211 	return (evDeselectFD(opaqueCtx, this->file));
212 }
213 
evUnhold(evContext opaqueCtx,evConnID id)214 int evUnhold(evContext opaqueCtx, evConnID id) {
215 	evConn *this = id.opaque;
216 	int ret;
217 
218 	if ((this->flags & EV_CONN_LISTEN) == 0) {
219 		errno = EINVAL;
220 		return (-1);
221 	}
222 	if ((this->flags & EV_CONN_SELECTED) != 0)
223 		return (0);
224 	ret = evSelectFD(opaqueCtx, this->fd, EV_READ, listener, this,
225 			 &this->file);
226 	if (ret == 0)
227 		this->flags |= EV_CONN_SELECTED;
228 	return (ret);
229 }
230 
231 int
evTryAccept(evContext opaqueCtx,evConnID id,int * sys_errno)232 evTryAccept(evContext opaqueCtx, evConnID id, int *sys_errno) {
233 	evContext_p *ctx = opaqueCtx.opaque;
234 	evConn *conn = id.opaque;
235 	evAccept *new;
236 
237 	if ((conn->flags & EV_CONN_LISTEN) == 0) {
238 		errno = EINVAL;
239 		return (-1);
240 	}
241 	OKNEW(new);
242 	new->conn = conn;
243 	new->ralen = sizeof new->ra;
244 	new->fd = accept(conn->fd, &new->ra.sa, &new->ralen);
245 	if (new->fd > ctx->highestFD) {
246 		close(new->fd);
247 		new->fd = -1;
248 		new->ioErrno = ENOTSOCK;
249 	}
250 	if (new->fd >= 0) {
251 		new->lalen = sizeof new->la;
252 		if (GETXXXNAME(getsockname, new->fd, new->la.sa, new->lalen) < 0) {
253 			new->ioErrno = errno;
254 			(void) close(new->fd);
255 			new->fd = -1;
256 		} else
257 			new->ioErrno = 0;
258 	} else {
259 		new->ioErrno = errno;
260 		if (errno == EAGAIN || errno == EWOULDBLOCK) {
261 			FREE(new);
262 			return (-1);
263 		}
264 	}
265 	INIT_LINK(new, link);
266 	APPEND(ctx->accepts, new, link);
267 	*sys_errno = new->ioErrno;
268 	return (0);
269 }
270 
271 /* Private. */
272 
273 static void
listener(evContext opaqueCtx,void * uap,int fd,int evmask)274 listener(evContext opaqueCtx, void *uap, int fd, int evmask) {
275 	evContext_p *ctx = opaqueCtx.opaque;
276 	evConn *conn = uap;
277 	union {
278 		struct sockaddr    sa;
279 		struct sockaddr_in in;
280 #ifndef NO_SOCKADDR_UN
281 		struct sockaddr_un un;
282 #endif
283 	} la, ra;
284 	int new;
285 	ISC_SOCKLEN_T lalen = 0, ralen;
286 
287 	REQUIRE((evmask & EV_READ) != 0);
288 	ralen = sizeof ra;
289 	new = accept(fd, &ra.sa, &ralen);
290 	if (new > ctx->highestFD) {
291 		close(new);
292 		new = -1;
293 		errno = ENOTSOCK;
294 	}
295 	if (new >= 0) {
296 		lalen = sizeof la;
297 		if (GETXXXNAME(getsockname, new, la.sa, lalen) < 0) {
298 			int save = errno;
299 
300 			(void) close(new);
301 			errno = save;
302 			new = -1;
303 		}
304 	} else if (errno == EAGAIN || errno == EWOULDBLOCK)
305 		return;
306 	(*conn->func)(opaqueCtx, conn->uap, new, &la.sa, lalen, &ra.sa, ralen);
307 }
308 
309 static void
connector(evContext opaqueCtx,void * uap,int fd,int evmask)310 connector(evContext opaqueCtx, void *uap, int fd, int evmask) {
311 	evConn *conn = uap;
312 	union {
313 		struct sockaddr    sa;
314 		struct sockaddr_in in;
315 #ifndef NO_SOCKADDR_UN
316 		struct sockaddr_un un;
317 #endif
318 	} la, ra;
319 	ISC_SOCKLEN_T lalen, ralen;
320 #ifndef NETREAD_BROKEN
321 	char buf[1];
322 #endif
323 	void *conn_uap;
324 	evConnFunc conn_func;
325 	evConnID id;
326 	int socket_errno = 0;
327 	ISC_SOCKLEN_T optlen;
328 
329 	UNUSED(evmask);
330 
331 	lalen = sizeof la;
332 	ralen = sizeof ra;
333 	conn_uap = conn->uap;
334 	conn_func = conn->func;
335 	id.opaque = conn;
336 #ifdef SO_ERROR
337 	optlen = sizeof socket_errno;
338 	if (fd < 0 &&
339 	    getsockopt(conn->fd, SOL_SOCKET, SO_ERROR, (char *)&socket_errno,
340 		       &optlen) < 0)
341 		socket_errno = errno;
342 	else
343 		errno = socket_errno;
344 #endif
345 	if (evCancelConn(opaqueCtx, id) < 0 ||
346 	    socket_errno ||
347 #ifdef NETREAD_BROKEN
348 	    0 ||
349 #else
350 	    read(fd, buf, 0) < 0 ||
351 #endif
352 	    GETXXXNAME(getsockname, fd, la.sa, lalen) < 0 ||
353 	    GETXXXNAME(getpeername, fd, ra.sa, ralen) < 0) {
354 		int save = errno;
355 
356 		(void) close(fd);	/*%< XXX closing caller's fd */
357 		errno = save;
358 		fd = -1;
359 	}
360 	(*conn_func)(opaqueCtx, conn_uap, fd, &la.sa, lalen, &ra.sa, ralen);
361 }
362 
363 /*! \file */
364