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1.2 ! xsa 1: /* $OpenBSD: buf.c,v 1.1 2006/04/26 02:55:13 joris Exp $ */
1.1 joris 2: /*
3: * Copyright (c) 2003 Jean-Francois Brousseau <jfb@openbsd.org>
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:
27: #include "includes.h"
28:
29: #include "buf.h"
30: #include "xmalloc.h"
31: #include "worklist.h"
32:
33: #define BUF_INCR 128
34:
35: struct rcs_buf {
36: u_int cb_flags;
37:
38: /* buffer handle and size */
39: u_char *cb_buf;
40: size_t cb_size;
41:
42: /* start and length of valid data in buffer */
43: u_char *cb_cur;
44: size_t cb_len;
45: };
46:
47: #define SIZE_LEFT(b) (b->cb_size - (size_t)(b->cb_cur - b->cb_buf) \
48: - b->cb_len)
49:
50: static void rcs_buf_grow(BUF *, size_t);
51:
52: /*
53: * rcs_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 rcs_buf_free(),
57: * once the buffer is no longer needed.
58: */
59: BUF *
60: rcs_buf_alloc(size_t len, u_int flags)
61: {
62: BUF *b;
63:
64: b = xmalloc(sizeof(*b));
65: /* Postpone creation of zero-sized buffers */
66: if (len > 0)
67: b->cb_buf = xcalloc(1, len);
68: else
69: b->cb_buf = NULL;
70:
71: b->cb_flags = flags;
72: b->cb_size = len;
73: b->cb_cur = b->cb_buf;
74: b->cb_len = 0;
75:
76: return (b);
77: }
78:
79: /*
80: * rcs_buf_load()
81: *
82: * Open the file specified by <path> and load all of its contents into a
83: * buffer.
84: * Returns the loaded buffer on success.
85: */
86: BUF *
87: rcs_buf_load(const char *path, u_int flags)
88: {
89: int fd;
90: ssize_t ret;
91: size_t len;
92: u_char *bp;
93: struct stat st;
94: BUF *buf;
95:
96: if ((fd = open(path, O_RDONLY, 0600)) == -1) {
97: warn("%s", path);
98: return (NULL);
99: }
100:
101: if (fstat(fd, &st) == -1)
102: err(1, "rcs_buf_load: fstat: %s", path);
103:
104: buf = rcs_buf_alloc((size_t)st.st_size, flags);
105: for (bp = buf->cb_cur; ; bp += (size_t)ret) {
106: len = SIZE_LEFT(buf);
107: ret = read(fd, bp, len);
108: if (ret == -1) {
109: rcs_buf_free(buf);
110: err(1, "rcs_buf_load: read: %s", strerror(errno));
111: } else if (ret == 0)
112: break;
113:
114: buf->cb_len += (size_t)ret;
115: }
116:
117: (void)close(fd);
118:
119: return (buf);
120: }
121:
122: /*
123: * rcs_buf_free()
124: *
125: * Free the buffer <b> and all associated data.
126: */
127: void
128: rcs_buf_free(BUF *b)
129: {
130: if (b->cb_buf != NULL)
131: xfree(b->cb_buf);
132: xfree(b);
133: }
134:
135: /*
136: * rcs_buf_release()
137: *
138: * Free the buffer <b>'s structural information but do not free the contents
139: * of the buffer. Instead, they are returned and should be freed later using
140: * free().
141: */
142: void *
143: rcs_buf_release(BUF *b)
144: {
145: u_char *tmp;
146:
147: tmp = b->cb_buf;
148: xfree(b);
149: return (tmp);
150: }
151:
152: /*
153: * rcs_buf_empty()
154: *
155: * Empty the contents of the buffer <b> and reset pointers.
156: */
157: void
158: rcs_buf_empty(BUF *b)
159: {
160: memset(b->cb_buf, 0, b->cb_size);
161: b->cb_cur = b->cb_buf;
162: b->cb_len = 0;
163: }
164:
165: /*
166: * rcs_buf_set()
167: *
168: * Set the contents of the buffer <b> at offset <off> to the first <len>
169: * bytes of data found at <src>. If the buffer was not created with
170: * BUF_AUTOEXT, as many bytes as possible will be copied in the buffer.
171: */
172: ssize_t
173: rcs_buf_set(BUF *b, const void *src, size_t len, size_t off)
174: {
175: size_t rlen = 0;
176:
177: if (b->cb_size < (len + off)) {
178: if ((b->cb_flags & BUF_AUTOEXT)) {
179: rcs_buf_grow(b, len + off - b->cb_size);
180: rlen = len + off;
181: } else {
182: rlen = b->cb_size - off;
183: }
184: } else {
185: rlen = len;
186: }
187:
188: b->cb_len = rlen;
189: memcpy((b->cb_buf + off), src, rlen);
190:
191: if (b->cb_len == 0) {
192: b->cb_cur = b->cb_buf + off;
193: b->cb_len = rlen;
194: }
195:
196: return (rlen);
197: }
198:
199: /*
200: * rcs_buf_putc()
201: *
202: * Append a single character <c> to the end of the buffer <b>.
203: */
204: void
205: rcs_buf_putc(BUF *b, int c)
206: {
207: u_char *bp;
208:
209: bp = b->cb_cur + b->cb_len;
210: if (bp == (b->cb_buf + b->cb_size)) {
211: /* extend */
212: if (b->cb_flags & BUF_AUTOEXT)
213: rcs_buf_grow(b, (size_t)BUF_INCR);
214: else
215: errx(1, "rcs_buf_putc failed");
216:
217: /* the buffer might have been moved */
218: bp = b->cb_cur + b->cb_len;
219: }
220: *bp = (u_char)c;
221: b->cb_len++;
222: }
223:
224: /*
225: * rcs_buf_getc()
226: *
227: * Return u_char at buffer position <pos>.
228: *
229: */
230: u_char
231: rcs_buf_getc(BUF *b, size_t pos)
232: {
233: return (b->cb_cur[pos]);
234: }
235:
236: /*
237: * rcs_buf_append()
238: *
239: * Append <len> bytes of data pointed to by <data> to the buffer <b>. If the
240: * buffer is too small to accept all data, it will attempt to append as much
241: * data as possible, or if the BUF_AUTOEXT flag is set for the buffer, it
242: * will get resized to an appropriate size to accept all data.
243: * Returns the number of bytes successfully appended to the buffer.
244: */
245: ssize_t
246: rcs_buf_append(BUF *b, const void *data, size_t len)
247: {
248: size_t left, rlen;
249: u_char *bp, *bep;
250:
251: bp = b->cb_cur + b->cb_len;
252: bep = b->cb_buf + b->cb_size;
253: left = bep - bp;
254: rlen = len;
255:
256: if (left < len) {
257: if (b->cb_flags & BUF_AUTOEXT) {
258: rcs_buf_grow(b, len - left);
259: bp = b->cb_cur + b->cb_len;
260: } else
261: rlen = bep - bp;
262: }
263:
264: memcpy(bp, data, rlen);
265: b->cb_len += rlen;
266:
267: return (rlen);
268: }
269:
270: /*
271: * rcs_buf_fappend()
272: *
273: */
274: ssize_t
275: rcs_buf_fappend(BUF *b, const char *fmt, ...)
276: {
277: ssize_t ret;
278: char *str;
279: va_list vap;
280:
281: va_start(vap, fmt);
282: ret = vasprintf(&str, fmt, vap);
283: va_end(vap);
284:
285: if (ret == -1)
286: errx(1, "rcs_buf_fappend: failed to format data");
287:
288: ret = rcs_buf_append(b, str, (size_t)ret);
289: xfree(str);
290: return (ret);
291: }
292:
293: /*
294: * rcs_buf_len()
295: *
296: * Returns the size of the buffer that is being used.
297: */
298: size_t
299: rcs_buf_len(BUF *b)
300: {
301: return (b->cb_len);
302: }
303:
304: /*
305: * rcs_buf_write_fd()
306: *
307: * Write the contents of the buffer <b> to the specified <fd>
308: */
309: int
310: rcs_buf_write_fd(BUF *b, int fd)
311: {
312: u_char *bp;
313: size_t len;
314: ssize_t ret;
315:
316: len = b->cb_len;
317: bp = b->cb_cur;
318:
319: do {
320: ret = write(fd, bp, len);
321: if (ret == -1) {
322: if (errno == EINTR || errno == EAGAIN)
323: continue;
324: return (-1);
325: }
326:
327: len -= (size_t)ret;
328: bp += (size_t)ret;
329: } while (len > 0);
330:
331: return (0);
332: }
333:
334: /*
335: * rcs_buf_write()
336: *
337: * Write the contents of the buffer <b> to the file whose path is given in
338: * <path>. If the file does not exist, it is created with mode <mode>.
339: */
340: int
341: rcs_buf_write(BUF *b, const char *path, mode_t mode)
342: {
343: int fd;
344: open:
345: if ((fd = open(path, O_WRONLY|O_CREAT|O_TRUNC, mode)) == -1) {
346: if (errno == EACCES && unlink(path) != -1)
347: goto open;
348: else
349: err(1, "open: `%s'", path);
350: }
351:
352: if (rcs_buf_write_fd(b, fd) == -1) {
353: (void)unlink(path);
354: errx(1, "rcs_buf_write: rcs_buf_write_fd: `%s'", path);
355: }
356:
357: if (fchmod(fd, mode) < 0)
358: warn("permissions not set on file %s", path);
359:
360: (void)close(fd);
361:
362: return (0);
363: }
364:
365: /*
366: * rcs_buf_write_stmp()
367: *
368: * Write the contents of the buffer <b> to a temporary file whose path is
369: * specified using <template> (see mkstemp.3). NB. This function will modify
370: * <template>, as per mkstemp
371: */
372: void
373: rcs_buf_write_stmp(BUF *b, char *template, mode_t mode)
374: {
375: int fd;
376:
377: if ((fd = mkstemp(template)) == -1)
378: err(1, "mkstemp: `%s'", template);
379:
380: rcs_worklist_add(template, &rcs_temp_files);
381:
382: if (rcs_buf_write_fd(b, fd) == -1) {
383: (void)unlink(template);
384: errx(1, "rcs_buf_write_stmp: rcs_buf_write_fd: `%s'", template);
385: }
386:
387: if (fchmod(fd, mode) < 0)
388: warn("permissions not set on temporary file %s",
389: template);
390:
391: (void)close(fd);
392: }
393:
394: /*
395: * rcs_buf_grow()
396: *
397: * Grow the buffer <b> by <len> bytes. The contents are unchanged by this
398: * operation regardless of the result.
399: */
400: static void
401: rcs_buf_grow(BUF *b, size_t len)
402: {
403: void *tmp;
404: size_t diff;
405:
406: diff = b->cb_cur - b->cb_buf;
407: tmp = xrealloc(b->cb_buf, 1, b->cb_size + len);
408: b->cb_buf = tmp;
409: b->cb_size += len;
410:
411: /* readjust pointers in case the buffer moved in memory */
412: b->cb_cur = b->cb_buf + diff;
413: }