external/bsd/libevent/dist/buffer.c

   1 /*      $NetBSD$        */
   2 /*
   3  * Copyright (c) 2002, 2003 Niels Provos <provos@citi.umich.edu>
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 3. The name of the author may not be used to endorse or promote products
  15  *    derived from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 #ifdef HAVE_CONFIG_H
  30 #include "config.h"
  31 #endif
  32
  33 #ifdef WIN32
  34 #include <winsock2.h>
  35 #include <windows.h>
  36 #endif
  37
  38 #ifdef HAVE_VASPRINTF
  39 /* If we have vasprintf, we need to define this before we include stdio.h. */
  40 #define _GNU_SOURCE
  41 #endif
  42
  43 #include <sys/types.h>
  44
  45 #ifdef HAVE_SYS_TIME_H
  46 #include <sys/time.h>
  47 #endif
  48
  49 #ifdef HAVE_SYS_IOCTL_H
  50 #include <sys/ioctl.h>
  51 #endif
  52
  53 #include <assert.h>
  54 #include <errno.h>
  55 #include <stdio.h>
  56 #include <stdlib.h>
  57 #include <string.h>
  58 #ifdef HAVE_STDARG_H
  59 #include <stdarg.h>
  60 #endif
  61 #ifdef HAVE_UNISTD_H
  62 #include <unistd.h>
  63 #endif
  64
  65 #include "event.h"
  66 #include "config.h"
  67 #include "evutil.h"
  68
  69 struct evbuffer *
  70 evbuffer_new(void)
  71 {
  72         struct evbuffer *buffer;
  73
  74         buffer = calloc(1, sizeof(struct evbuffer));
  75
  76         return (buffer);
  77 }
  78
  79 void
  80 evbuffer_free(struct evbuffer *buffer)
  81 {
  82         if (buffer->orig_buffer != NULL)
  83                 free(buffer->orig_buffer);
  84         free(buffer);
  85 }
  86
  87 /*
  88  * This is a destructive add.  The data from one buffer moves into
  89  * the other buffer.
  90  */
  91
  92 #define SWAP(x,y) do { \
  93         (x)->buffer = (y)->buffer; \
  94         (x)->orig_buffer = (y)->orig_buffer; \
  95         (x)->misalign = (y)->misalign; \
  96         (x)->totallen = (y)->totallen; \
  97         (x)->off = (y)->off; \
  98 } while (0)
  99
 100 int
 101 evbuffer_add_buffer(struct evbuffer *outbuf, struct evbuffer *inbuf)
 102 {
 103         int res;
 104
 105         /* Short cut for better performance */
 106         if (outbuf->off == 0) {
 107                 struct evbuffer tmp;
 108                 size_t oldoff = inbuf->off;
 109
 110                 /* Swap them directly */
 111                 SWAP(&tmp, outbuf);
 112                 SWAP(outbuf, inbuf);
 113                 SWAP(inbuf, &tmp);
 114
 115                 /*
 116                  * Optimization comes with a price; we need to notify the
 117                  * buffer if necessary of the changes. oldoff is the amount
 118                  * of data that we transfered from inbuf to outbuf
 119                  */
 120                 if (inbuf->off != oldoff && inbuf->cb != NULL)
 121                         (*inbuf->cb)(inbuf, oldoff, inbuf->off, inbuf->cbarg);
 122                 if (oldoff && outbuf->cb != NULL)
 123                         (*outbuf->cb)(outbuf, 0, oldoff, outbuf->cbarg);
 124
 125                 return (0);
 126         }
 127
 128         res = evbuffer_add(outbuf, inbuf->buffer, inbuf->off);
 129         if (res == 0) {
 130                 /* We drain the input buffer on success */
 131                 evbuffer_drain(inbuf, inbuf->off);
 132         }
 133
 134         return (res);
 135 }
 136
 137 int
 138 evbuffer_add_vprintf(struct evbuffer *buf, const char *fmt, va_list ap)
 139 {
 140         char *buffer;
 141         size_t space;
 142         size_t oldoff = buf->off;
 143         int sz;
 144         va_list aq;
 145
 146         /* make sure that at least some space is available */
 147         evbuffer_expand(buf, 64);
 148         for (;;) {
 149                 size_t used = buf->misalign + buf->off;
 150                 buffer = (char *)buf->buffer + buf->off;
 151                 assert(buf->totallen >= used);
 152                 space = buf->totallen - used;
 153
 154 #ifndef va_copy
 155 #define va_copy(dst, src)       memcpy(&(dst), &(src), sizeof(va_list))
 156 #endif
 157                 va_copy(aq, ap);
 158
 159                 sz = evutil_vsnprintf(buffer, space, fmt, aq);
 160
 161                 va_end(aq);
 162
 163                 if (sz < 0)
 164                         return (-1);
 165                 if ((size_t)sz < space) {
 166                         buf->off += sz;
 167                         if (buf->cb != NULL)
 168                                 (*buf->cb)(buf, oldoff, buf->off, buf->cbarg);
 169                         return (sz);
 170                 }
 171                 if (evbuffer_expand(buf, sz + 1) == -1)
 172                         return (-1);
 173
 174         }
 175         /* NOTREACHED */
 176 }
 177
 178 int
 179 evbuffer_add_printf(struct evbuffer *buf, const char *fmt, ...)
 180 {
 181         int res = -1;
 182         va_list ap;
 183
 184         va_start(ap, fmt);
 185         res = evbuffer_add_vprintf(buf, fmt, ap);
 186         va_end(ap);
 187
 188         return (res);
 189 }
 190
 191 /* Reads data from an event buffer and drains the bytes read */
 192
 193 int
 194 evbuffer_remove(struct evbuffer *buf, void *data, size_t datlen)
 195 {
 196         size_t nread = datlen;
 197         if (nread >= buf->off)
 198                 nread = buf->off;
 199
 200         memcpy(data, buf->buffer, nread);
 201         evbuffer_drain(buf, nread);
 202
 203         return (nread);
 204 }
 205
 206 /*
 207  * Reads a line terminated by either '\r\n', '\n\r' or '\r' or '\n'.
 208  * The returned buffer needs to be freed by the called.
 209  */
 210
 211 char *
 212 evbuffer_readline(struct evbuffer *buffer)
 213 {
 214         u_char *data = EVBUFFER_DATA(buffer);
 215         size_t len = EVBUFFER_LENGTH(buffer);
 216         char *line;
 217         unsigned int i;
 218
 219         for (i = 0; i < len; i++) {
 220                 if (data[i] == '\r' || data[i] == '\n')
 221                         break;
 222         }
 223
 224         if (i == len)
 225                 return (NULL);
 226
 227         if ((line = malloc(i + 1)) == NULL) {
 228                 fprintf(stderr, "%s: out of memory\n", __func__);
 229                 evbuffer_drain(buffer, i);
 230                 return (NULL);
 231         }
 232
 233         memcpy(line, data, i);
 234         line[i] = '\0';
 235
 236         /*
 237          * Some protocols terminate a line with '\r\n', so check for
 238          * that, too.
 239          */
 240         if ( i < len - 1 ) {
 241                 char fch = data[i], sch = data[i+1];
 242
 243                 /* Drain one more character if needed */
 244                 if ( (sch == '\r' || sch == '\n') && sch != fch )
 245                         i += 1;
 246         }
 247
 248         evbuffer_drain(buffer, i + 1);
 249
 250         return (line);
 251 }
 252
 253 /* Adds data to an event buffer */
 254
 255 static void
 256 evbuffer_align(struct evbuffer *buf)
 257 {
 258         memmove(buf->orig_buffer, buf->buffer, buf->off);
 259         buf->buffer = buf->orig_buffer;
 260         buf->misalign = 0;
 261 }
 262
 263 /* Expands the available space in the event buffer to at least datlen */
 264
 265 int
 266 evbuffer_expand(struct evbuffer *buf, size_t datlen)
 267 {
 268         size_t need = buf->misalign + buf->off + datlen;
 269
 270         /* If we can fit all the data, then we don't have to do anything */
 271         if (buf->totallen >= need)
 272                 return (0);
 273
 274         /*
 275          * If the misalignment fulfills our data needs, we just force an
 276          * alignment to happen.  Afterwards, we have enough space.
 277          */
 278         if (buf->misalign >= datlen) {
 279                 evbuffer_align(buf);
 280         } else {
 281                 void *newbuf;
 282                 size_t length = buf->totallen;
 283
 284                 if (length < 256)
 285                         length = 256;
 286                 while (length < need)
 287                         length <<= 1;
 288
 289                 if (buf->orig_buffer != buf->buffer)
 290                         evbuffer_align(buf);
 291                 if ((newbuf = realloc(buf->buffer, length)) == NULL)
 292                         return (-1);
 293
 294                 buf->orig_buffer = buf->buffer = newbuf;
 295                 buf->totallen = length;
 296         }
 297
 298         return (0);
 299 }
 300
 301 int
 302 evbuffer_add(struct evbuffer *buf, const void *data, size_t datlen)
 303 {
 304         size_t need = buf->misalign + buf->off + datlen;
 305         size_t oldoff = buf->off;
 306
 307         if (buf->totallen < need) {
 308                 if (evbuffer_expand(buf, datlen) == -1)
 309                         return (-1);
 310         }
 311
 312         memcpy(buf->buffer + buf->off, data, datlen);
 313         buf->off += datlen;
 314
 315         if (datlen && buf->cb != NULL)
 316                 (*buf->cb)(buf, oldoff, buf->off, buf->cbarg);
 317
 318         return (0);
 319 }
 320
 321 void
 322 evbuffer_drain(struct evbuffer *buf, size_t len)
 323 {
 324         size_t oldoff = buf->off;
 325
 326         if (len >= buf->off) {
 327                 buf->off = 0;
 328                 buf->buffer = buf->orig_buffer;
 329                 buf->misalign = 0;
 330                 goto done;
 331         }
 332
 333         buf->buffer += len;
 334         buf->misalign += len;
 335
 336         buf->off -= len;
 337
 338  done:
 339         /* Tell someone about changes in this buffer */
 340         if (buf->off != oldoff && buf->cb != NULL)
 341                 (*buf->cb)(buf, oldoff, buf->off, buf->cbarg);
 342
 343 }
 344
 345 /*
 346  * Reads data from a file descriptor into a buffer.
 347  */
 348
 349 #define EVBUFFER_MAX_READ       4096
 350
 351 int
 352 evbuffer_read(struct evbuffer *buf, int fd, int howmuch)
 353 {
 354         u_char *p;
 355         size_t oldoff = buf->off;
 356         int n = EVBUFFER_MAX_READ;
 357
 358 #if defined(FIONREAD)
 359 #ifdef WIN32
 360         long lng = n;
 361         if (ioctlsocket(fd, FIONREAD, &lng) == -1 || (n=lng) == 0) {
 362 #else
 363         if (ioctl(fd, FIONREAD, &n) == -1 || n == 0) {
 364 #endif
 365                 n = EVBUFFER_MAX_READ;
 366         } else if (n > EVBUFFER_MAX_READ && n > howmuch) {
 367                 /*
 368                  * It's possible that a lot of data is available for
 369                  * reading.  We do not want to exhaust resources
 370                  * before the reader has a chance to do something
 371                  * about it.  If the reader does not tell us how much
 372                  * data we should read, we artifically limit it.
 373                  */
 374                 if ((size_t)n > buf->totallen << 2)
 375                         n = buf->totallen << 2;
 376                 if (n < EVBUFFER_MAX_READ)
 377                         n = EVBUFFER_MAX_READ;
 378         }
 379 #endif
 380         if (howmuch < 0 || howmuch > n)
 381                 howmuch = n;
 382
 383         /* If we don't have FIONREAD, we might waste some space here */
 384         if (evbuffer_expand(buf, howmuch) == -1)
 385                 return (-1);
 386
 387         /* We can append new data at this point */
 388         p = buf->buffer + buf->off;
 389
 390 #ifndef WIN32
 391         n = read(fd, p, howmuch);
 392 #else
 393         n = recv(fd, p, howmuch, 0);
 394 #endif
 395         if (n == -1)
 396                 return (-1);
 397         if (n == 0)
 398                 return (0);
 399
 400         buf->off += n;
 401
 402         /* Tell someone about changes in this buffer */
 403         if (buf->off != oldoff && buf->cb != NULL)
 404                 (*buf->cb)(buf, oldoff, buf->off, buf->cbarg);
 405
 406         return (n);
 407 }
 408
 409 int
 410 evbuffer_write(struct evbuffer *buffer, int fd)
 411 {
 412         int n;
 413
 414 #ifndef WIN32
 415         n = write(fd, buffer->buffer, buffer->off);
 416 #else
 417         n = send(fd, buffer->buffer, buffer->off, 0);
 418 #endif
 419         if (n == -1)
 420                 return (-1);
 421         if (n == 0)
 422                 return (0);
 423         evbuffer_drain(buffer, n);
 424
 425         return (n);
 426 }
 427
 428 u_char *
 429 evbuffer_find(struct evbuffer *buffer, const u_char *what, size_t len)
 430 {
 431         u_char *search = buffer->buffer, *end = search + buffer->off;
 432         u_char *p;
 433
 434         while (search < end &&
 435             (p = memchr(search, *what, end - search)) != NULL) {
 436                 if (p + len > end)
 437                         break;
 438                 if (memcmp(p, what, len) == 0)
 439                         return (p);
 440                 search = p + 1;
 441         }
 442
 443         return (NULL);
 444 }
 445
 446 void evbuffer_setcb(struct evbuffer *buffer,
 447     void (*cb)(struct evbuffer *, size_t, size_t, void *),
 448     void *cbarg)
 449 {
 450         buffer->cb = cb;
 451         buffer->cbarg = cbarg;
 452 }