Annotation of src/usr.bin/cvs/buf.c, Revision 1.32
1.32 ! niallo 1: /* $OpenBSD: buf.c,v 1.31 2006/01/16 21:02:36 niallo Exp $ */
1.1 jfb 2: /*
1.2 jfb 3: * Copyright (c) 2003 Jean-Francois Brousseau <jfb@openbsd.org>
1.1 jfb 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: *
10: * 1. Redistributions of source code must retain the above copyright
11: * notice, this list of conditions and the following disclaimer.
12: * 2. The name of the author may not be used to endorse or promote products
13: * derived from this software without specific prior written permission.
14: *
15: * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
16: * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
17: * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
18: * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
19: * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
20: * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
21: * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
22: * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
23: * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
24: * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25: */
26:
1.28 xsa 27: #include "includes.h"
1.1 jfb 28:
29: #include "buf.h"
30: #include "log.h"
1.19 joris 31: #include "xmalloc.h"
1.1 jfb 32:
1.15 xsa 33: #define BUF_INCR 128
1.1 jfb 34:
35: struct cvs_buf {
1.15 xsa 36: u_int cb_flags;
1.1 jfb 37:
38: /* buffer handle and size */
1.15 xsa 39: u_char *cb_buf;
40: size_t cb_size;
1.1 jfb 41:
42: /* start and length of valid data in buffer */
1.15 xsa 43: u_char *cb_cur;
44: size_t cb_len;
1.1 jfb 45: };
46:
1.16 moritz 47: #define SIZE_LEFT(b) (b->cb_size - (size_t)(b->cb_cur - b->cb_buf) \
48: - b->cb_len)
1.1 jfb 49:
1.15 xsa 50: static ssize_t cvs_buf_grow(BUF *, size_t);
1.1 jfb 51:
52: /*
53: * cvs_buf_alloc()
54: *
55: * Create a new buffer structure and return a pointer to it. This structure
56: * uses dynamically-allocated memory and must be freed with cvs_buf_free(),
57: * once the buffer is no longer needed.
58: */
1.15 xsa 59: BUF *
1.1 jfb 60: cvs_buf_alloc(size_t len, u_int flags)
61: {
62: BUF *b;
63:
1.19 joris 64: b = (BUF *)xmalloc(sizeof(*b));
1.30 niallo 65: /* Postpone creation of zero-sized buffers */
66: if (len > 0) {
67: b->cb_buf = xmalloc(len);
68: memset(b->cb_buf, 0, len);
1.31 niallo 69: } else
70: b->cb_buf = NULL;
1.1 jfb 71:
72: b->cb_flags = flags;
73: b->cb_size = len;
1.8 jfb 74: b->cb_cur = b->cb_buf;
1.1 jfb 75: b->cb_len = 0;
76:
77: return (b);
78: }
79:
80: /*
81: * cvs_buf_load()
82: *
83: * Open the file specified by <path> and load all of its contents into a
84: * buffer.
1.20 xsa 85: * Returns the loaded buffer on success.
1.1 jfb 86: */
1.15 xsa 87: BUF *
1.1 jfb 88: cvs_buf_load(const char *path, u_int flags)
89: {
90: int fd;
91: ssize_t ret;
92: size_t len;
1.8 jfb 93: u_char *bp;
1.1 jfb 94: struct stat st;
95: BUF *buf;
96:
1.20 xsa 97: if ((fd = open(path, O_RDONLY, 0600)) == -1)
98: fatal("cvs_buf_load: open: `%s': %s", path, strerror(errno));
1.1 jfb 99:
1.20 xsa 100: if (fstat(fd, &st) == -1)
101: fatal("cvs_buf_load: fstat: %s", strerror(errno));
1.1 jfb 102:
1.25 joris 103: buf = cvs_buf_alloc((size_t)st.st_size, flags);
1.1 jfb 104: for (bp = buf->cb_cur; ; bp += (size_t)ret) {
1.16 moritz 105: len = SIZE_LEFT(buf);
1.1 jfb 106: ret = read(fd, bp, len);
107: if (ret == -1) {
1.8 jfb 108: cvs_buf_free(buf);
1.20 xsa 109: fatal("cvs_buf_load: read: %s", strerror(errno));
1.5 deraadt 110: } else if (ret == 0)
1.1 jfb 111: break;
112:
113: buf->cb_len += (size_t)ret;
114: }
115:
116: (void)close(fd);
117:
118: return (buf);
119: }
120:
121: /*
122: * cvs_buf_free()
123: *
124: * Free the buffer <b> and all associated data.
125: */
126: void
127: cvs_buf_free(BUF *b)
128: {
1.31 niallo 129: if (b->cb_buf != NULL)
130: xfree(b->cb_buf);
1.19 joris 131: xfree(b);
1.1 jfb 132: }
133:
134: /*
135: * cvs_buf_release()
136: *
137: * Free the buffer <b>'s structural information but do not free the contents
138: * of the buffer. Instead, they are returned and should be freed later using
139: * free().
140: */
1.17 xsa 141: void *
1.1 jfb 142: cvs_buf_release(BUF *b)
143: {
1.8 jfb 144: u_char *tmp;
1.6 tedu 145:
1.1 jfb 146: tmp = b->cb_buf;
1.19 joris 147: xfree(b);
1.1 jfb 148: return (tmp);
149: }
150:
151: /*
152: * cvs_buf_empty()
153: *
154: * Empty the contents of the buffer <b> and reset pointers.
155: */
156: void
157: cvs_buf_empty(BUF *b)
158: {
1.16 moritz 159: memset(b->cb_buf, 0, b->cb_size);
1.8 jfb 160: b->cb_cur = b->cb_buf;
1.1 jfb 161: b->cb_len = 0;
162: }
163:
164: /*
165: * cvs_buf_copy()
166: *
167: * Copy the first <len> bytes of data in the buffer <b> starting at offset
168: * <off> in the destination buffer <dst>, which can accept up to <len> bytes.
169: * Returns the number of bytes successfully copied, or -1 on failure.
170: */
171: ssize_t
172: cvs_buf_copy(BUF *b, size_t off, void *dst, size_t len)
173: {
174: size_t rc;
175:
176: if (off > b->cb_len)
1.21 xsa 177: fatal("cvs_buf_copy failed");
1.1 jfb 178:
179: rc = MIN(len, (b->cb_len - off));
1.16 moritz 180: memcpy(dst, b->cb_buf + off, rc);
1.1 jfb 181:
182: return (ssize_t)rc;
183: }
184:
185: /*
186: * cvs_buf_set()
187: *
1.16 moritz 188: * Set the contents of the buffer <b> at offset <off> to the first <len>
189: * bytes of data found at <src>. If the buffer was not created with
190: * BUF_AUTOEXT, as many bytes as possible will be copied in the buffer.
1.1 jfb 191: */
1.16 moritz 192: ssize_t
1.1 jfb 193: cvs_buf_set(BUF *b, const void *src, size_t len, size_t off)
194: {
1.23 xsa 195: size_t rlen = 0;
1.1 jfb 196:
197: if (b->cb_size < (len + off)) {
1.20 xsa 198: if ((b->cb_flags & BUF_AUTOEXT) &&
199: (cvs_buf_grow(b, len + off - b->cb_size) < 0))
200: fatal("cvs_buf_set failed");
1.1 jfb 201: else
202: rlen = b->cb_size - off;
1.5 deraadt 203: } else
1.1 jfb 204: rlen = len;
205:
206: memcpy((b->cb_buf + off), src, rlen);
207:
208: if (b->cb_len == 0) {
209: b->cb_cur = b->cb_buf + off;
210: b->cb_len = rlen;
211: }
212:
1.16 moritz 213: return (rlen);
1.1 jfb 214: }
215:
216: /*
217: * cvs_buf_putc()
218: *
219: * Append a single character <c> to the end of the buffer <b>.
1.21 xsa 220: * Returns 0 on success.
1.1 jfb 221: */
222: int
223: cvs_buf_putc(BUF *b, int c)
224: {
225: u_char *bp;
226:
227: bp = b->cb_cur + b->cb_len;
228: if (bp == (b->cb_buf + b->cb_size)) {
229: /* extend */
230: if (!(b->cb_flags & BUF_AUTOEXT) ||
1.18 xsa 231: (cvs_buf_grow(b, (size_t)BUF_INCR) < 0))
1.21 xsa 232: fatal("cvs_buf_putc failed");
1.1 jfb 233:
234: /* the buffer might have been moved */
235: bp = b->cb_cur + b->cb_len;
236: }
237: *bp = (u_char)c;
238: b->cb_len++;
239:
240: return (0);
1.29 niallo 241: }
242:
243: /*
244: * cvs_buf_getc()
245: *
246: * Return u_char at buffer position <pos>.
247: *
248: */
249: u_char
250: cvs_buf_getc(BUF *b, u_int pos)
251: {
252: return (b->cb_cur[pos]);
1.1 jfb 253: }
254:
255: /*
256: * cvs_buf_append()
257: *
258: * Append <len> bytes of data pointed to by <data> to the buffer <b>. If the
259: * buffer is too small to accept all data, it will attempt to append as much
260: * data as possible, or if the BUF_AUTOEXT flag is set for the buffer, it
261: * will get resized to an appropriate size to accept all data.
1.27 joris 262: * Returns the number of bytes successfully appended to the buffer.
1.1 jfb 263: */
264: ssize_t
265: cvs_buf_append(BUF *b, const void *data, size_t len)
266: {
267: size_t left, rlen;
1.8 jfb 268: u_char *bp, *bep;
1.1 jfb 269:
270: bp = b->cb_cur + b->cb_len;
271: bep = b->cb_buf + b->cb_size;
272: left = bep - bp;
273: rlen = len;
274:
275: if (left < len) {
276: if (b->cb_flags & BUF_AUTOEXT) {
277: if (cvs_buf_grow(b, len - left) < 0)
1.20 xsa 278: fatal("cvs_buf_append failed");
1.1 jfb 279: bp = b->cb_cur + b->cb_len;
1.5 deraadt 280: } else
1.1 jfb 281: rlen = bep - bp;
282: }
283:
284: memcpy(bp, data, rlen);
285: b->cb_len += rlen;
286:
287: return (rlen);
288: }
289:
290: /*
291: * cvs_buf_fappend()
292: *
293: */
294: int
295: cvs_buf_fappend(BUF *b, const char *fmt, ...)
296: {
297: int ret;
298: char *str;
299: va_list vap;
300:
301: va_start(vap, fmt);
1.4 pat 302: ret = vasprintf(&str, fmt, vap);
303: va_end(vap);
1.1 jfb 304:
1.20 xsa 305: if (ret == -1)
306: fatal("cvs_buf_fappend: failed to format data");
1.1 jfb 307:
1.18 xsa 308: ret = cvs_buf_append(b, str, (size_t)ret);
1.19 joris 309: xfree(str);
1.1 jfb 310: return (ret);
311: }
312:
313: /*
1.16 moritz 314: * cvs_buf_len()
1.1 jfb 315: *
316: * Returns the size of the buffer that is being used.
317: */
318: size_t
1.16 moritz 319: cvs_buf_len(BUF *b)
1.1 jfb 320: {
321: return (b->cb_len);
322: }
323:
324: /*
325: * cvs_buf_peek()
326: *
327: * Peek at the contents of the buffer <b> at offset <off>.
328: */
1.17 xsa 329: const void *
1.1 jfb 330: cvs_buf_peek(BUF *b, size_t off)
331: {
332: if (off >= b->cb_len)
333: return (NULL);
334:
335: return (b->cb_buf + off);
336: }
337:
338: /*
1.7 djm 339: * cvs_buf_write_fd()
1.1 jfb 340: *
1.7 djm 341: * Write the contents of the buffer <b> to the specified <fd>
1.1 jfb 342: */
343: int
1.7 djm 344: cvs_buf_write_fd(BUF *b, int fd)
1.1 jfb 345: {
346: u_char *bp;
347: size_t len;
348: ssize_t ret;
349:
350: len = b->cb_len;
351: bp = b->cb_cur;
352:
353: do {
1.16 moritz 354: ret = write(fd, bp, len);
1.1 jfb 355: if (ret == -1) {
1.7 djm 356: if (errno == EINTR || errno == EAGAIN)
357: continue;
1.22 xsa 358: return (-1);
1.1 jfb 359: }
360:
361: len -= (size_t)ret;
362: bp += (size_t)ret;
363: } while (len > 0);
364:
1.7 djm 365: return (0);
366: }
367:
368: /*
369: * cvs_buf_write()
370: *
371: * Write the contents of the buffer <b> to the file whose path is given in
372: * <path>. If the file does not exist, it is created with mode <mode>.
373: */
374: int
375: cvs_buf_write(BUF *b, const char *path, mode_t mode)
376: {
1.22 xsa 377: int fd;
1.32 ! niallo 378: open:
! 379: if ((fd = open(path, O_WRONLY|O_CREAT|O_TRUNC, mode)) == -1) {
! 380: if ((errno == EACCES) && (unlink(path) != -1))
! 381: goto open;
! 382: else
! 383: fatal("open: `%s': %s", path, strerror(errno));
! 384: }
1.7 djm 385:
1.22 xsa 386: if (cvs_buf_write_fd(b, fd) == -1) {
1.7 djm 387: (void)unlink(path);
1.22 xsa 388: fatal("cvs_buf_write: cvs_buf_write_fd: `%s'", path);
1.7 djm 389: }
1.1 jfb 390: (void)close(fd);
1.24 joris 391:
392: if (chmod(path, mode) < 0)
393: fatal("cvs_buf_write: chmod failed: %s", strerror(errno));
1.1 jfb 394:
1.22 xsa 395: return (0);
1.1 jfb 396: }
397:
1.7 djm 398: /*
399: * cvs_buf_write_stmp()
400: *
1.13 joris 401: * Write the contents of the buffer <b> to a temporary file whose path is
1.7 djm 402: * specified using <template> (see mkstemp.3). NB. This function will modify
403: * <template>, as per mkstemp
404: */
405: int
406: cvs_buf_write_stmp(BUF *b, char *template, mode_t mode)
407: {
1.22 xsa 408: int fd;
1.7 djm 409:
1.20 xsa 410: if ((fd = mkstemp(template)) == -1)
411: fatal("mkstemp: `%s': %s", template, strerror(errno));
1.7 djm 412:
1.22 xsa 413: if (cvs_buf_write_fd(b, fd) == -1) {
1.7 djm 414: (void)unlink(template);
1.22 xsa 415: fatal("cvs_buf_write_stmp: cvs_buf_write_fd: `%s'", template);
1.7 djm 416: }
417: (void)close(fd);
418:
1.22 xsa 419: return (0);
1.7 djm 420: }
1.1 jfb 421:
422: /*
423: * cvs_buf_grow()
424: *
425: * Grow the buffer <b> by <len> bytes. The contents are unchanged by this
426: * operation regardless of the result.
427: * Returns the new size on success, or -1 on failure.
428: */
429: static ssize_t
430: cvs_buf_grow(BUF *b, size_t len)
431: {
432: void *tmp;
433: size_t diff;
434:
1.8 jfb 435: diff = b->cb_cur - b->cb_buf;
1.30 niallo 436: /* Buffer not allocated yet */
437: if (b->cb_size == 0)
438: tmp = xmalloc(len);
439: else
440: tmp = xrealloc(b->cb_buf, b->cb_size + len);
1.1 jfb 441: b->cb_buf = (u_char *)tmp;
442: b->cb_size += len;
443:
444: /* readjust pointers in case the buffer moved in memory */
445: b->cb_cur = b->cb_buf + diff;
446:
447: return (ssize_t)b->cb_size;
448: }