Annotation of embedaddon/libpdel/io/filter.c, revision 1.1
1.1 ! misho 1:
! 2: /*
! 3: * Copyright (c) 2001-2002 Packet Design, LLC.
! 4: * All rights reserved.
! 5: *
! 6: * Subject to the following obligations and disclaimer of warranty,
! 7: * use and redistribution of this software, in source or object code
! 8: * forms, with or without modifications are expressly permitted by
! 9: * Packet Design; provided, however, that:
! 10: *
! 11: * (i) Any and all reproductions of the source or object code
! 12: * must include the copyright notice above and the following
! 13: * disclaimer of warranties; and
! 14: * (ii) No rights are granted, in any manner or form, to use
! 15: * Packet Design trademarks, including the mark "PACKET DESIGN"
! 16: * on advertising, endorsements, or otherwise except as such
! 17: * appears in the above copyright notice or in the software.
! 18: *
! 19: * THIS SOFTWARE IS BEING PROVIDED BY PACKET DESIGN "AS IS", AND
! 20: * TO THE MAXIMUM EXTENT PERMITTED BY LAW, PACKET DESIGN MAKES NO
! 21: * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING
! 22: * THIS SOFTWARE, INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED
! 23: * WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE,
! 24: * OR NON-INFRINGEMENT. PACKET DESIGN DOES NOT WARRANT, GUARANTEE,
! 25: * OR MAKE ANY REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS
! 26: * OF THE USE OF THIS SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY,
! 27: * RELIABILITY OR OTHERWISE. IN NO EVENT SHALL PACKET DESIGN BE
! 28: * LIABLE FOR ANY DAMAGES RESULTING FROM OR ARISING OUT OF ANY USE
! 29: * OF THIS SOFTWARE, INCLUDING WITHOUT LIMITATION, ANY DIRECT,
! 30: * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, PUNITIVE, OR CONSEQUENTIAL
! 31: * DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, LOSS OF
! 32: * USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY THEORY OF
! 33: * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
! 34: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
! 35: * THE USE OF THIS SOFTWARE, EVEN IF PACKET DESIGN IS ADVISED OF
! 36: * THE POSSIBILITY OF SUCH DAMAGE.
! 37: *
! 38: * Author: Archie Cobbs <archie@freebsd.org>
! 39: */
! 40:
! 41: #include <sys/types.h>
! 42: #include <sys/param.h>
! 43:
! 44: #include <assert.h>
! 45: #include <stdio.h>
! 46: #include <stdarg.h>
! 47: #include <string.h>
! 48: #include <errno.h>
! 49: #include <stdlib.h>
! 50:
! 51: #include "structs/structs.h"
! 52: #include "structs/type/array.h"
! 53:
! 54: #include "io/filter.h"
! 55: #include "util/typed_mem.h"
! 56:
! 57: /************************************************************************
! 58: FILTER STREAMS
! 59: ************************************************************************/
! 60:
! 61: /* funopen(3) methods used by filter_fopen() */
! 62: static int filter_stream_read(void *cookie, char *buf, int len);
! 63: static int filter_stream_write(void *cookie, const char *buf, int len);
! 64: static int filter_stream_close(void *cookie);
! 65:
! 66: /* State used by filter_fopen() */
! 67: struct filter_stream {
! 68: FILE *fp; /* underlying stream */
! 69: struct filter *filter; /* filter object */
! 70: int output; /* input or output? */
! 71: int eof; /* eof has been reached */
! 72: int flags; /* flags */
! 73: };
! 74:
! 75: /*
! 76: * Create a new filter stream using the supplied filter.
! 77: */
! 78: FILE *
! 79: filter_fopen(struct filter *filter, int flags, FILE *fp, const char *mode)
! 80: {
! 81: struct filter_stream *fs;
! 82: int output;
! 83:
! 84: if (strcmp(mode, "r") == 0)
! 85: output = 0;
! 86: else if (strcmp(mode, "w") == 0)
! 87: output = 1;
! 88: else {
! 89: errno = EINVAL;
! 90: return (NULL);
! 91: }
! 92: if ((fs = MALLOC("filter_stream", sizeof(*fs))) == NULL)
! 93: return (NULL);
! 94: memset(fs, 0, sizeof(*fs));
! 95: fs->filter = filter;
! 96: fs->fp = fp;
! 97: fs->output = output;
! 98: fs->flags = flags;
! 99: if ((fp = funopen(fs,
! 100: !fs->output ? filter_stream_read : NULL,
! 101: fs->output ? filter_stream_write : NULL,
! 102: NULL, filter_stream_close)) == NULL) {
! 103: FREE("filter_stream", fs);
! 104: return (NULL);
! 105: }
! 106: return (fp);
! 107: }
! 108:
! 109: static int
! 110: filter_stream_read(void *cookie, char *buf, int len)
! 111: {
! 112: struct filter_stream *const fs = cookie;
! 113: u_char fbuf[1024];
! 114: int total = 0;
! 115: int flen;
! 116: int num;
! 117: int i;
! 118:
! 119: /*
! 120: * Read from underlying stream until we've read "len" bytes
! 121: * from the filter or the underlying stream returns EOF.
! 122: */
! 123: for (total = 0; len > 0; ) {
! 124:
! 125: /* Read any remaining output from the filter */
! 126: if ((num = filter_read(fs->filter, buf, len)) == -1)
! 127: return (-1);
! 128: buf += num;
! 129: len -= num;
! 130: total += num;
! 131:
! 132: /* No more data to be read from underlying stream? */
! 133: if (fs->eof || len == 0)
! 134: break;
! 135:
! 136: /*
! 137: * Read more data from the underlying stream,
! 138: * but not any more than necessary.
! 139: */
! 140: flen = filter_convert(fs->filter, len, 0);
! 141: flen = MIN(flen, sizeof(fbuf));
! 142: clearerr(fs->fp);
! 143: if ((num = fread(fbuf, 1, flen, fs->fp)) == 0) {
! 144: if (ferror(fs->fp))
! 145: return (total > 0 ? total : -1);
! 146: fs->eof = 1;
! 147: if (filter_end(fs->filter) == -1)
! 148: return (total > 0 ? total : -1);
! 149: }
! 150:
! 151: /* Send the data we just read through the filter */
! 152: for (i = 0; i < num; i += flen) {
! 153: if ((flen = filter_write(fs->filter,
! 154: fbuf + i, num - i)) == -1)
! 155: return (total > 0 ? total : -1);
! 156: }
! 157: }
! 158: return (total);
! 159: }
! 160:
! 161: static int
! 162: filter_stream_write(void *cookie, const char *buf, int len)
! 163: {
! 164: struct filter_stream *const fs = cookie;
! 165: u_char fbuf[1024];
! 166: int flen;
! 167:
! 168: if ((len = filter_write(fs->filter, buf, len)) == -1)
! 169: return (-1);
! 170: while ((flen = filter_read(fs->filter, fbuf, sizeof(fbuf))) > 0) {
! 171: if (fwrite(fbuf, 1, flen, fs->fp) != flen)
! 172: return (-1);
! 173: }
! 174: return (len);
! 175: }
! 176:
! 177: static int
! 178: filter_stream_close(void *cookie)
! 179: {
! 180: struct filter_stream *const fs = cookie;
! 181: u_char buf[1024];
! 182: int len;
! 183:
! 184: if (fs->output) {
! 185: (void)filter_end(fs->filter); /* XXX */
! 186: while ((len = filter_read(fs->filter, buf, sizeof(buf))) > 0) {
! 187: if (fwrite(buf, 1, len, fs->fp) != len)
! 188: break;
! 189: }
! 190: fflush(fs->fp);
! 191: }
! 192: if ((fs->flags & FILTER_NO_CLOSE_STREAM) == 0)
! 193: fclose(fs->fp);
! 194: if ((fs->flags & FILTER_NO_DESTROY_FILTER) == 0)
! 195: filter_destroy(&fs->filter);
! 196:
! 197: /* Done */
! 198: FREE("filter_stream", fs);
! 199: return (0);
! 200: }
! 201:
! 202: /************************************************************************
! 203: FILTER PROCESSING
! 204: ************************************************************************/
! 205:
! 206: /*
! 207: * Filter data in memory using a filter.
! 208: */
! 209: int
! 210: filter_process(struct filter *filter, const void *input, int ilen,
! 211: int final, u_char **outputp, const char *mtype)
! 212: {
! 213: int nw, w;
! 214: int nr, r;
! 215: int olen;
! 216:
! 217: /* Allocate buffer big enough to hold filter output */
! 218: olen = filter_convert(filter, ilen, 1) + 10;
! 219: if ((*outputp = MALLOC(mtype, olen)) == NULL)
! 220: return (-1);
! 221:
! 222: /* Filter data */
! 223: for (w = r = 0; w < ilen; w += nw, r += nr) {
! 224: if ((nw = filter_write(filter,
! 225: (char *)input + w, MIN(ilen - w, 1024))) == -1)
! 226: goto fail;
! 227: if ((nr = filter_read(filter, *outputp + r, olen - r)) == -1)
! 228: goto fail;
! 229: }
! 230: if (final) {
! 231: if (filter_end(filter) == -1)
! 232: goto fail;
! 233: do {
! 234: if ((nr = filter_read(filter,
! 235: *outputp + r, olen - r)) == -1)
! 236: goto fail;
! 237: r += nr;
! 238: } while (nr != 0);
! 239: }
! 240: assert(r < olen);
! 241:
! 242: /* Done */
! 243: (*outputp)[r] = 0;
! 244: return (r);
! 245:
! 246: fail:
! 247: FREE(mtype, *outputp);
! 248: *outputp = NULL;
! 249: return (-1);
! 250: }
! 251:
! 252: /************************************************************************
! 253: FILTER METHOD WRAPPERS
! 254: ************************************************************************/
! 255:
! 256: int
! 257: filter_read(struct filter *filter, void *data, int len)
! 258: {
! 259: return (*filter->read)(filter, data, len);
! 260: }
! 261:
! 262: int
! 263: filter_write(struct filter *filter, const void *data, int len)
! 264: {
! 265: return (*filter->write)(filter, data, len);
! 266: }
! 267:
! 268: int
! 269: filter_end(struct filter *filter)
! 270: {
! 271: return (*filter->end)(filter);
! 272: }
! 273:
! 274: int
! 275: filter_convert(struct filter *filter, int num, int forward)
! 276: {
! 277: return (*filter->convert)(filter, num, forward);
! 278: }
! 279:
! 280: void
! 281: filter_destroy(struct filter **filterp)
! 282: {
! 283: struct filter *const filter = *filterp;
! 284:
! 285: if (filter != NULL)
! 286: (*filter->destroy)(filterp);
! 287: }
! 288:
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