1 /*- 2 * SPDX-License-Identifier: ISC 3 * 4 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") 5 * Copyright (c) 1996-1999 by Internet Software Consortium 6 * 7 * Permission to use, copy, modify, and distribute this software for any 8 * purpose with or without fee is hereby granted, provided that the above 9 * copyright notice and this permission notice appear in all copies. 10 * 11 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES 12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR 14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT 17 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 18 */ 19 20 /* ev_streams.c - implement asynch stream file IO for the eventlib 21 * vix 04mar96 [initial] 22 */ 23 24 #if !defined(LINT) && !defined(CODECENTER) 25 static const char rcsid[] = "$Id: ev_streams.c,v 1.5 2005/04/27 04:56:36 sra Exp $"; 26 #endif 27 #include <sys/cdefs.h> 28 #include "port_before.h" 29 #ifndef _LIBC 30 #include "fd_setsize.h" 31 #endif 32 33 #include <sys/types.h> 34 #include <sys/uio.h> 35 36 #include <errno.h> 37 38 #include <isc/eventlib.h> 39 #ifndef _LIBC 40 #include <isc/assertions.h> 41 #endif 42 #include "eventlib_p.h" 43 44 #include "port_after.h" 45 46 #ifndef _LIBC 47 static int copyvec(evStream *str, const struct iovec *iov, int iocnt); 48 static void consume(evStream *str, size_t bytes); 49 static void done(evContext opaqueCtx, evStream *str); 50 static void writable(evContext opaqueCtx, void *uap, int fd, int evmask); 51 static void readable(evContext opaqueCtx, void *uap, int fd, int evmask); 52 #endif 53 54 struct iovec 55 evConsIovec(void *buf, size_t cnt) { 56 struct iovec ret; 57 58 memset(&ret, 0xf5, sizeof ret); 59 ret.iov_base = buf; 60 ret.iov_len = cnt; 61 return (ret); 62 } 63 64 #ifndef _LIBC 65 int 66 evWrite(evContext opaqueCtx, int fd, const struct iovec *iov, int iocnt, 67 evStreamFunc func, void *uap, evStreamID *id) 68 { 69 evContext_p *ctx = opaqueCtx.opaque; 70 evStream *new; 71 int save; 72 73 OKNEW(new); 74 new->func = func; 75 new->uap = uap; 76 new->fd = fd; 77 new->flags = 0; 78 if (evSelectFD(opaqueCtx, fd, EV_WRITE, writable, new, &new->file) < 0) 79 goto free; 80 if (copyvec(new, iov, iocnt) < 0) 81 goto free; 82 new->prevDone = NULL; 83 new->nextDone = NULL; 84 if (ctx->streams != NULL) 85 ctx->streams->prev = new; 86 new->prev = NULL; 87 new->next = ctx->streams; 88 ctx->streams = new; 89 if (id != NULL) 90 id->opaque = new; 91 return (0); 92 free: 93 save = errno; 94 FREE(new); 95 errno = save; 96 return (-1); 97 } 98 99 int 100 evRead(evContext opaqueCtx, int fd, const struct iovec *iov, int iocnt, 101 evStreamFunc func, void *uap, evStreamID *id) 102 { 103 evContext_p *ctx = opaqueCtx.opaque; 104 evStream *new; 105 int save; 106 107 OKNEW(new); 108 new->func = func; 109 new->uap = uap; 110 new->fd = fd; 111 new->flags = 0; 112 if (evSelectFD(opaqueCtx, fd, EV_READ, readable, new, &new->file) < 0) 113 goto free; 114 if (copyvec(new, iov, iocnt) < 0) 115 goto free; 116 new->prevDone = NULL; 117 new->nextDone = NULL; 118 if (ctx->streams != NULL) 119 ctx->streams->prev = new; 120 new->prev = NULL; 121 new->next = ctx->streams; 122 ctx->streams = new; 123 if (id) 124 id->opaque = new; 125 return (0); 126 free: 127 save = errno; 128 FREE(new); 129 errno = save; 130 return (-1); 131 } 132 133 int 134 evTimeRW(evContext opaqueCtx, evStreamID id, evTimerID timer) /*ARGSUSED*/ { 135 evStream *str = id.opaque; 136 137 UNUSED(opaqueCtx); 138 139 str->timer = timer; 140 str->flags |= EV_STR_TIMEROK; 141 return (0); 142 } 143 144 int 145 evUntimeRW(evContext opaqueCtx, evStreamID id) /*ARGSUSED*/ { 146 evStream *str = id.opaque; 147 148 UNUSED(opaqueCtx); 149 150 str->flags &= ~EV_STR_TIMEROK; 151 return (0); 152 } 153 154 int 155 evCancelRW(evContext opaqueCtx, evStreamID id) { 156 evContext_p *ctx = opaqueCtx.opaque; 157 evStream *old = id.opaque; 158 159 /* 160 * The streams list is doubly threaded. First, there's ctx->streams 161 * that's used by evDestroy() to find and cancel all streams. Second, 162 * there's ctx->strDone (head) and ctx->strLast (tail) which thread 163 * through the potentially smaller number of "IO completed" streams, 164 * used in evGetNext() to avoid scanning the entire list. 165 */ 166 167 /* Unlink from ctx->streams. */ 168 if (old->prev != NULL) 169 old->prev->next = old->next; 170 else 171 ctx->streams = old->next; 172 if (old->next != NULL) 173 old->next->prev = old->prev; 174 175 /* 176 * If 'old' is on the ctx->strDone list, remove it. Update 177 * ctx->strLast if necessary. 178 */ 179 if (old->prevDone == NULL && old->nextDone == NULL) { 180 /* 181 * Either 'old' is the only item on the done list, or it's 182 * not on the done list. If the former, then we unlink it 183 * from the list. If the latter, we leave the list alone. 184 */ 185 if (ctx->strDone == old) { 186 ctx->strDone = NULL; 187 ctx->strLast = NULL; 188 } 189 } else { 190 if (old->prevDone != NULL) 191 old->prevDone->nextDone = old->nextDone; 192 else 193 ctx->strDone = old->nextDone; 194 if (old->nextDone != NULL) 195 old->nextDone->prevDone = old->prevDone; 196 else 197 ctx->strLast = old->prevDone; 198 } 199 200 /* Deallocate the stream. */ 201 if (old->file.opaque) 202 evDeselectFD(opaqueCtx, old->file); 203 memput(old->iovOrig, sizeof (struct iovec) * old->iovOrigCount); 204 FREE(old); 205 return (0); 206 } 207 208 /* Copy a scatter/gather vector and initialize a stream handler's IO. */ 209 static int 210 copyvec(evStream *str, const struct iovec *iov, int iocnt) { 211 int i; 212 213 str->iovOrig = (struct iovec *)memget(sizeof(struct iovec) * iocnt); 214 if (str->iovOrig == NULL) { 215 errno = ENOMEM; 216 return (-1); 217 } 218 str->ioTotal = 0; 219 for (i = 0; i < iocnt; i++) { 220 str->iovOrig[i] = iov[i]; 221 str->ioTotal += iov[i].iov_len; 222 } 223 str->iovOrigCount = iocnt; 224 str->iovCur = str->iovOrig; 225 str->iovCurCount = str->iovOrigCount; 226 str->ioDone = 0; 227 return (0); 228 } 229 230 /* Pull off or truncate lead iovec(s). */ 231 static void 232 consume(evStream *str, size_t bytes) { 233 while (bytes > 0U) { 234 if (bytes < (size_t)str->iovCur->iov_len) { 235 str->iovCur->iov_len -= bytes; 236 str->iovCur->iov_base = (void *) 237 ((u_char *)str->iovCur->iov_base + bytes); 238 str->ioDone += bytes; 239 bytes = 0; 240 } else { 241 bytes -= str->iovCur->iov_len; 242 str->ioDone += str->iovCur->iov_len; 243 str->iovCur++; 244 str->iovCurCount--; 245 } 246 } 247 } 248 249 /* Add a stream to Done list and deselect the FD. */ 250 static void 251 done(evContext opaqueCtx, evStream *str) { 252 evContext_p *ctx = opaqueCtx.opaque; 253 254 if (ctx->strLast != NULL) { 255 str->prevDone = ctx->strLast; 256 ctx->strLast->nextDone = str; 257 ctx->strLast = str; 258 } else { 259 INSIST(ctx->strDone == NULL); 260 ctx->strDone = ctx->strLast = str; 261 } 262 evDeselectFD(opaqueCtx, str->file); 263 str->file.opaque = NULL; 264 /* evDrop() will call evCancelRW() on us. */ 265 } 266 267 /* Dribble out some bytes on the stream. (Called by evDispatch().) */ 268 static void 269 writable(evContext opaqueCtx, void *uap, int fd, int evmask) { 270 evStream *str = uap; 271 int bytes; 272 273 UNUSED(evmask); 274 275 bytes = writev(fd, str->iovCur, str->iovCurCount); 276 if (bytes > 0) { 277 if ((str->flags & EV_STR_TIMEROK) != 0) 278 evTouchIdleTimer(opaqueCtx, str->timer); 279 consume(str, bytes); 280 } else { 281 if (bytes < 0 && errno != EINTR) { 282 str->ioDone = -1; 283 str->ioErrno = errno; 284 } 285 } 286 if (str->ioDone == -1 || str->ioDone == str->ioTotal) 287 done(opaqueCtx, str); 288 } 289 290 /* Scoop up some bytes from the stream. (Called by evDispatch().) */ 291 static void 292 readable(evContext opaqueCtx, void *uap, int fd, int evmask) { 293 evStream *str = uap; 294 int bytes; 295 296 UNUSED(evmask); 297 298 bytes = readv(fd, str->iovCur, str->iovCurCount); 299 if (bytes > 0) { 300 if ((str->flags & EV_STR_TIMEROK) != 0) 301 evTouchIdleTimer(opaqueCtx, str->timer); 302 consume(str, bytes); 303 } else { 304 if (bytes == 0) 305 str->ioDone = 0; 306 else { 307 if (errno != EINTR) { 308 str->ioDone = -1; 309 str->ioErrno = errno; 310 } 311 } 312 } 313 if (str->ioDone <= 0 || str->ioDone == str->ioTotal) 314 done(opaqueCtx, str); 315 } 316 #endif 317 318 /*! \file */ 319