Annotation of src/usr.bin/cvs/buf.c, Revision 1.37
1.37 ! ray 1: /* $OpenBSD: buf.c,v 1.36 2006/03/15 19:48:12 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:
1.34 niallo 97: if ((fd = open(path, O_RDONLY, 0600)) == -1) {
1.35 xsa 98: cvs_log(LP_ERRNO, "%s", path);
1.34 niallo 99: return (NULL);
100: }
1.1 jfb 101:
1.20 xsa 102: if (fstat(fd, &st) == -1)
103: fatal("cvs_buf_load: fstat: %s", strerror(errno));
1.1 jfb 104:
1.25 joris 105: buf = cvs_buf_alloc((size_t)st.st_size, flags);
1.1 jfb 106: for (bp = buf->cb_cur; ; bp += (size_t)ret) {
1.16 moritz 107: len = SIZE_LEFT(buf);
1.1 jfb 108: ret = read(fd, bp, len);
109: if (ret == -1) {
1.8 jfb 110: cvs_buf_free(buf);
1.20 xsa 111: fatal("cvs_buf_load: read: %s", strerror(errno));
1.5 deraadt 112: } else if (ret == 0)
1.1 jfb 113: break;
114:
115: buf->cb_len += (size_t)ret;
116: }
117:
118: (void)close(fd);
119:
120: return (buf);
121: }
122:
123: /*
124: * cvs_buf_free()
125: *
126: * Free the buffer <b> and all associated data.
127: */
128: void
129: cvs_buf_free(BUF *b)
130: {
1.31 niallo 131: if (b->cb_buf != NULL)
132: xfree(b->cb_buf);
1.19 joris 133: xfree(b);
1.1 jfb 134: }
135:
136: /*
137: * cvs_buf_release()
138: *
139: * Free the buffer <b>'s structural information but do not free the contents
140: * of the buffer. Instead, they are returned and should be freed later using
141: * free().
142: */
1.17 xsa 143: void *
1.1 jfb 144: cvs_buf_release(BUF *b)
145: {
1.8 jfb 146: u_char *tmp;
1.6 tedu 147:
1.1 jfb 148: tmp = b->cb_buf;
1.19 joris 149: xfree(b);
1.1 jfb 150: return (tmp);
151: }
152:
153: /*
154: * cvs_buf_empty()
155: *
156: * Empty the contents of the buffer <b> and reset pointers.
157: */
158: void
159: cvs_buf_empty(BUF *b)
160: {
1.16 moritz 161: memset(b->cb_buf, 0, b->cb_size);
1.8 jfb 162: b->cb_cur = b->cb_buf;
1.1 jfb 163: b->cb_len = 0;
164: }
165:
166: /*
167: * cvs_buf_copy()
168: *
169: * Copy the first <len> bytes of data in the buffer <b> starting at offset
170: * <off> in the destination buffer <dst>, which can accept up to <len> bytes.
171: * Returns the number of bytes successfully copied, or -1 on failure.
172: */
173: ssize_t
174: cvs_buf_copy(BUF *b, size_t off, void *dst, size_t len)
175: {
176: size_t rc;
177:
178: if (off > b->cb_len)
1.21 xsa 179: fatal("cvs_buf_copy failed");
1.1 jfb 180:
181: rc = MIN(len, (b->cb_len - off));
1.16 moritz 182: memcpy(dst, b->cb_buf + off, rc);
1.1 jfb 183:
184: return (ssize_t)rc;
185: }
186:
187: /*
188: * cvs_buf_set()
189: *
1.16 moritz 190: * Set the contents of the buffer <b> at offset <off> to the first <len>
191: * bytes of data found at <src>. If the buffer was not created with
192: * BUF_AUTOEXT, as many bytes as possible will be copied in the buffer.
1.1 jfb 193: */
1.16 moritz 194: ssize_t
1.1 jfb 195: cvs_buf_set(BUF *b, const void *src, size_t len, size_t off)
196: {
1.23 xsa 197: size_t rlen = 0;
1.1 jfb 198:
199: if (b->cb_size < (len + off)) {
1.20 xsa 200: if ((b->cb_flags & BUF_AUTOEXT) &&
201: (cvs_buf_grow(b, len + off - b->cb_size) < 0))
202: fatal("cvs_buf_set failed");
1.1 jfb 203: else
204: rlen = b->cb_size - off;
1.5 deraadt 205: } else
1.1 jfb 206: rlen = len;
207:
208: memcpy((b->cb_buf + off), src, rlen);
209:
210: if (b->cb_len == 0) {
211: b->cb_cur = b->cb_buf + off;
212: b->cb_len = rlen;
213: }
214:
1.16 moritz 215: return (rlen);
1.1 jfb 216: }
217:
218: /*
219: * cvs_buf_putc()
220: *
221: * Append a single character <c> to the end of the buffer <b>.
1.21 xsa 222: * Returns 0 on success.
1.1 jfb 223: */
224: int
225: cvs_buf_putc(BUF *b, int c)
226: {
227: u_char *bp;
228:
229: bp = b->cb_cur + b->cb_len;
230: if (bp == (b->cb_buf + b->cb_size)) {
231: /* extend */
232: if (!(b->cb_flags & BUF_AUTOEXT) ||
1.18 xsa 233: (cvs_buf_grow(b, (size_t)BUF_INCR) < 0))
1.21 xsa 234: fatal("cvs_buf_putc failed");
1.1 jfb 235:
236: /* the buffer might have been moved */
237: bp = b->cb_cur + b->cb_len;
238: }
239: *bp = (u_char)c;
240: b->cb_len++;
241:
242: return (0);
1.29 niallo 243: }
244:
245: /*
246: * cvs_buf_getc()
247: *
248: * Return u_char at buffer position <pos>.
249: *
250: */
251: u_char
252: cvs_buf_getc(BUF *b, u_int pos)
253: {
254: return (b->cb_cur[pos]);
1.1 jfb 255: }
256:
257: /*
258: * cvs_buf_append()
259: *
260: * Append <len> bytes of data pointed to by <data> to the buffer <b>. If the
261: * buffer is too small to accept all data, it will attempt to append as much
262: * data as possible, or if the BUF_AUTOEXT flag is set for the buffer, it
263: * will get resized to an appropriate size to accept all data.
1.27 joris 264: * Returns the number of bytes successfully appended to the buffer.
1.1 jfb 265: */
266: ssize_t
267: cvs_buf_append(BUF *b, const void *data, size_t len)
268: {
269: size_t left, rlen;
1.8 jfb 270: u_char *bp, *bep;
1.1 jfb 271:
272: bp = b->cb_cur + b->cb_len;
273: bep = b->cb_buf + b->cb_size;
274: left = bep - bp;
275: rlen = len;
276:
277: if (left < len) {
278: if (b->cb_flags & BUF_AUTOEXT) {
279: if (cvs_buf_grow(b, len - left) < 0)
1.20 xsa 280: fatal("cvs_buf_append failed");
1.1 jfb 281: bp = b->cb_cur + b->cb_len;
1.5 deraadt 282: } else
1.1 jfb 283: rlen = bep - bp;
284: }
285:
286: memcpy(bp, data, rlen);
287: b->cb_len += rlen;
288:
289: return (rlen);
290: }
291:
292: /*
293: * cvs_buf_fappend()
294: *
295: */
1.37 ! ray 296: ssize_t
1.1 jfb 297: cvs_buf_fappend(BUF *b, const char *fmt, ...)
298: {
1.37 ! ray 299: ssize_t ret;
1.1 jfb 300: char *str;
301: va_list vap;
302:
303: va_start(vap, fmt);
1.4 pat 304: ret = vasprintf(&str, fmt, vap);
305: va_end(vap);
1.1 jfb 306:
1.20 xsa 307: if (ret == -1)
308: fatal("cvs_buf_fappend: failed to format data");
1.1 jfb 309:
1.18 xsa 310: ret = cvs_buf_append(b, str, (size_t)ret);
1.19 joris 311: xfree(str);
1.1 jfb 312: return (ret);
313: }
314:
315: /*
1.16 moritz 316: * cvs_buf_len()
1.1 jfb 317: *
318: * Returns the size of the buffer that is being used.
319: */
320: size_t
1.16 moritz 321: cvs_buf_len(BUF *b)
1.1 jfb 322: {
323: return (b->cb_len);
324: }
325:
326: /*
327: * cvs_buf_peek()
328: *
329: * Peek at the contents of the buffer <b> at offset <off>.
330: */
1.17 xsa 331: const void *
1.1 jfb 332: cvs_buf_peek(BUF *b, size_t off)
333: {
334: if (off >= b->cb_len)
335: return (NULL);
336:
337: return (b->cb_buf + off);
338: }
339:
340: /*
1.7 djm 341: * cvs_buf_write_fd()
1.1 jfb 342: *
1.7 djm 343: * Write the contents of the buffer <b> to the specified <fd>
1.1 jfb 344: */
345: int
1.7 djm 346: cvs_buf_write_fd(BUF *b, int fd)
1.1 jfb 347: {
348: u_char *bp;
349: size_t len;
350: ssize_t ret;
351:
352: len = b->cb_len;
353: bp = b->cb_cur;
354:
355: do {
1.16 moritz 356: ret = write(fd, bp, len);
1.1 jfb 357: if (ret == -1) {
1.7 djm 358: if (errno == EINTR || errno == EAGAIN)
359: continue;
1.22 xsa 360: return (-1);
1.1 jfb 361: }
362:
363: len -= (size_t)ret;
364: bp += (size_t)ret;
365: } while (len > 0);
366:
1.7 djm 367: return (0);
368: }
369:
370: /*
371: * cvs_buf_write()
372: *
373: * Write the contents of the buffer <b> to the file whose path is given in
374: * <path>. If the file does not exist, it is created with mode <mode>.
375: */
376: int
377: cvs_buf_write(BUF *b, const char *path, mode_t mode)
378: {
1.22 xsa 379: int fd;
1.32 niallo 380: open:
381: if ((fd = open(path, O_WRONLY|O_CREAT|O_TRUNC, mode)) == -1) {
382: if ((errno == EACCES) && (unlink(path) != -1))
383: goto open;
384: else
385: fatal("open: `%s': %s", path, strerror(errno));
386: }
1.7 djm 387:
1.22 xsa 388: if (cvs_buf_write_fd(b, fd) == -1) {
1.7 djm 389: (void)unlink(path);
1.22 xsa 390: fatal("cvs_buf_write: cvs_buf_write_fd: `%s'", path);
1.7 djm 391: }
1.1 jfb 392: (void)close(fd);
1.24 joris 393:
394: if (chmod(path, mode) < 0)
395: fatal("cvs_buf_write: chmod failed: %s", strerror(errno));
1.1 jfb 396:
1.22 xsa 397: return (0);
1.1 jfb 398: }
399:
1.7 djm 400: /*
401: * cvs_buf_write_stmp()
402: *
1.13 joris 403: * Write the contents of the buffer <b> to a temporary file whose path is
1.7 djm 404: * specified using <template> (see mkstemp.3). NB. This function will modify
405: * <template>, as per mkstemp
406: */
407: int
408: cvs_buf_write_stmp(BUF *b, char *template, mode_t mode)
409: {
1.22 xsa 410: int fd;
1.7 djm 411:
1.20 xsa 412: if ((fd = mkstemp(template)) == -1)
413: fatal("mkstemp: `%s': %s", template, strerror(errno));
1.7 djm 414:
1.22 xsa 415: if (cvs_buf_write_fd(b, fd) == -1) {
1.7 djm 416: (void)unlink(template);
1.22 xsa 417: fatal("cvs_buf_write_stmp: cvs_buf_write_fd: `%s'", template);
1.7 djm 418: }
1.36 niallo 419: (void)fchmod(fd, mode);
1.7 djm 420: (void)close(fd);
421:
1.22 xsa 422: return (0);
1.7 djm 423: }
1.1 jfb 424:
425: /*
426: * cvs_buf_grow()
427: *
428: * Grow the buffer <b> by <len> bytes. The contents are unchanged by this
429: * operation regardless of the result.
430: * Returns the new size on success, or -1 on failure.
431: */
432: static ssize_t
433: cvs_buf_grow(BUF *b, size_t len)
434: {
435: void *tmp;
436: size_t diff;
437:
1.8 jfb 438: diff = b->cb_cur - b->cb_buf;
1.30 niallo 439: /* Buffer not allocated yet */
440: if (b->cb_size == 0)
441: tmp = xmalloc(len);
442: else
443: tmp = xrealloc(b->cb_buf, b->cb_size + len);
1.1 jfb 444: b->cb_buf = (u_char *)tmp;
445: b->cb_size += len;
446:
447: /* readjust pointers in case the buffer moved in memory */
448: b->cb_cur = b->cb_buf + diff;
449:
450: return (ssize_t)b->cb_size;
451: }