1 /* vi: set sw=4 ts=4: */
2 /*
3 * busybox patch applet to handle the unified diff format.
4 * Copyright (C) 2003 Glenn McGrath
5 *
6 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
7 *
8 * This applet is written to work with patches generated by GNU diff,
9 * where there is equivalent functionality busybox patch shall behave
10 * as per GNU patch.
11 *
12 * There is a SUSv3 specification for patch, however it looks to be
13 * incomplete, it doesnt even mention unified diff format.
14 * http://www.opengroup.org/onlinepubs/007904975/utilities/patch.html
15 *
16 * Issues
17 * - Non-interactive
18 * - Patches must apply cleanly or patch (not just one hunk) will fail.
19 * - Reject file isnt saved
20 */
21
22 #include "libbb.h"
23
copy_lines(FILE * src_stream,FILE * dst_stream,unsigned lines_count)24 static unsigned copy_lines(FILE *src_stream, FILE *dst_stream, unsigned lines_count)
25 {
26 while (src_stream && lines_count) {
27 char *line;
28 line = xmalloc_fgets(src_stream);
29 if (line == NULL) {
30 break;
31 }
32 if (fputs(line, dst_stream) == EOF) {
33 bb_simple_perror_msg_and_die("error writing to new file");
34 }
35 free(line);
36 lines_count--;
37 }
38 return lines_count;
39 }
40
41 /* If patch_level is -1 it will remove all directory names
42 * char *line must be greater than 4 chars
43 * returns NULL if the file doesnt exist or error
44 * returns malloc'ed filename
45 * NB: frees 1st argument!
46 */
extract_filename(char * line,int patch_level,const char * pat)47 static char *extract_filename(char *line, int patch_level, const char *pat)
48 {
49 char *temp = NULL, *filename_start_ptr = line + 4;
50
51 if (strncmp(line, pat, 4) == 0) {
52 /* Terminate string at end of source filename */
53 line[strcspn(line, "\t\n\r")] = '\0';
54
55 /* Skip over (patch_level) number of leading directories */
56 while (patch_level--) {
57 temp = strchr(filename_start_ptr, '/');
58 if (!temp)
59 break;
60 filename_start_ptr = temp + 1;
61 }
62 temp = xstrdup(filename_start_ptr);
63 }
64 free(line);
65 return temp;
66 }
67
68 int patch_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
patch_main(int argc UNUSED_PARAM,char ** argv)69 int patch_main(int argc UNUSED_PARAM, char **argv)
70 {
71 struct stat saved_stat;
72 char *patch_line;
73 FILE *patch_file;
74 int patch_level;
75 int ret = 0;
76 char plus = '+';
77 unsigned opt;
78 enum {
79 OPT_R = (1 << 2),
80 OPT_N = (1 << 3),
81 /*OPT_f = (1 << 4), ignored */
82 /*OPT_E = (1 << 5), ignored, this is the default */
83 /*OPT_g = (1 << 6), ignored */
84 OPT_dry_run = (1 << 7) * ENABLE_LONG_OPTS,
85 };
86
87 xfunc_error_retval = 2;
88 {
89 const char *p = "-1";
90 const char *i = "-"; /* compat */
91 #if ENABLE_LONG_OPTS
92 static const char patch_longopts[] ALIGN1 =
93 "strip\0" Required_argument "p"
94 "input\0" Required_argument "i"
95 "reverse\0" No_argument "R"
96 "forward\0" No_argument "N"
97 /* "Assume user knows what [s]he is doing, do not ask any questions": */
98 "force\0" No_argument "f" /*ignored*/
99 # if ENABLE_DESKTOP
100 "remove-empty-files\0" No_argument "E" /*ignored*/
101 /* "Controls actions when a file is under RCS or SCCS control,
102 * and does not exist or is read-only and matches the default version,
103 * or when a file is under ClearCase control and does not exist..."
104 * IOW: rather obscure option.
105 * But Gentoo's portage does use -g0 */
106 "get\0" Required_argument "g" /*ignored*/
107 # endif
108 "dry-run\0" No_argument "\xfd"
109 # if ENABLE_DESKTOP
110 "backup-if-mismatch\0" No_argument "\xfe" /*ignored*/
111 "no-backup-if-mismatch\0" No_argument "\xff" /*ignored*/
112 # endif
113 ;
114 #endif
115 /* -f,-E,-g are ignored */
116 opt = getopt32long(argv, "p:i:RN""fEg:", patch_longopts, &p, &i, NULL);
117 if (opt & OPT_R)
118 plus = '-';
119 patch_level = xatoi(p); /* can be negative! */
120 patch_file = xfopen_stdin(i);
121 }
122
123 patch_line = xmalloc_fgetline(patch_file);
124 while (patch_line) {
125 FILE *src_stream;
126 FILE *dst_stream;
127 //char *old_filename;
128 char *new_filename;
129 char *backup_filename = NULL;
130 unsigned src_cur_line = 1;
131 unsigned dst_cur_line = 0;
132 unsigned dst_beg_line;
133 unsigned bad_hunk_count = 0;
134 unsigned hunk_count = 0;
135 smallint copy_trailing_lines_flag = 0;
136
137 /* Skip everything upto the "---" marker
138 * No need to parse the lines "Only in <dir>", and "diff <args>"
139 */
140 do {
141 /* Extract the filename used before the patch was generated */
142 new_filename = extract_filename(patch_line, patch_level, "--- ");
143 // was old_filename above
144 patch_line = xmalloc_fgetline(patch_file);
145 if (!patch_line) goto quit;
146 } while (!new_filename);
147 free(new_filename); // "source" filename is irrelevant
148
149 new_filename = extract_filename(patch_line, patch_level, "+++ ");
150 if (!new_filename) {
151 bb_simple_error_msg_and_die("invalid patch");
152 }
153
154 /* Get access rights from the file to be patched */
155 if (stat(new_filename, &saved_stat) != 0) {
156 char *slash = strrchr(new_filename, '/');
157 if (slash) {
158 /* Create leading directories */
159 *slash = '\0';
160 bb_make_directory(new_filename, -1, FILEUTILS_RECUR);
161 *slash = '/';
162 }
163 src_stream = NULL;
164 saved_stat.st_mode = 0644;
165 } else if (!(opt & OPT_dry_run)) {
166 backup_filename = xasprintf("%s.orig", new_filename);
167 xrename(new_filename, backup_filename);
168 src_stream = xfopen_for_read(backup_filename);
169 } else
170 src_stream = xfopen_for_read(new_filename);
171
172 if (opt & OPT_dry_run) {
173 dst_stream = xfopen_for_write("/dev/null");
174 } else {
175 dst_stream = xfopen_for_write(new_filename);
176 fchmod(fileno(dst_stream), saved_stat.st_mode);
177 }
178
179 printf("patching file %s\n", new_filename);
180
181 /* Handle all hunks for this file */
182 patch_line = xmalloc_fgets(patch_file);
183 while (patch_line) {
184 unsigned count;
185 unsigned src_beg_line;
186 unsigned hunk_offset_start;
187 unsigned src_last_line = 1;
188 unsigned dst_last_line = 1;
189
190 if ((sscanf(patch_line, "@@ -%u,%u +%u,%u", &src_beg_line, &src_last_line, &dst_beg_line, &dst_last_line) < 3)
191 && (sscanf(patch_line, "@@ -%u +%u,%u", &src_beg_line, &dst_beg_line, &dst_last_line) < 2)
192 ) {
193 /* No more hunks for this file */
194 break;
195 }
196 if (plus != '+') {
197 /* reverse patch */
198 unsigned tmp = src_last_line;
199 src_last_line = dst_last_line;
200 dst_last_line = tmp;
201 tmp = src_beg_line;
202 src_beg_line = dst_beg_line;
203 dst_beg_line = tmp;
204 }
205 hunk_count++;
206
207 if (src_beg_line && dst_beg_line) {
208 /* Copy unmodified lines upto start of hunk */
209 /* src_beg_line will be 0 if it's a new file */
210 count = src_beg_line - src_cur_line;
211 if (copy_lines(src_stream, dst_stream, count)) {
212 bb_simple_error_msg_and_die("bad src file");
213 }
214 src_cur_line += count;
215 dst_cur_line += count;
216 copy_trailing_lines_flag = 1;
217 }
218 src_last_line += hunk_offset_start = src_cur_line;
219 dst_last_line += dst_cur_line;
220
221 while (1) {
222 free(patch_line);
223 patch_line = xmalloc_fgets(patch_file);
224 if (patch_line == NULL)
225 break; /* EOF */
226 if (!*patch_line) {
227 /* whitespace-damaged patch with "" lines */
228 free(patch_line);
229 patch_line = xstrdup(" ");
230 }
231 if ((*patch_line != '-') && (*patch_line != '+')
232 && (*patch_line != ' ')
233 ) {
234 break; /* End of hunk */
235 }
236 if (*patch_line != plus) { /* '-' or ' ' */
237 char *src_line = NULL;
238 if (src_cur_line == src_last_line)
239 break;
240 if (src_stream) {
241 src_line = xmalloc_fgets(src_stream);
242 if (src_line) {
243 int diff = strcmp(src_line, patch_line + 1);
244 src_cur_line++;
245 free(src_line);
246 if (diff)
247 src_line = NULL;
248 }
249 }
250 /* Do not patch an already patched hunk with -N */
251 if (src_line == 0 && (opt & OPT_N)) {
252 continue;
253 }
254 if (!src_line) {
255 bb_error_msg("hunk #%u FAILED at %u", hunk_count, hunk_offset_start);
256 bad_hunk_count++;
257 break;
258 }
259 if (*patch_line != ' ') { /* '-' */
260 continue;
261 }
262 }
263 if (dst_cur_line == dst_last_line)
264 break;
265 fputs(patch_line + 1, dst_stream);
266 dst_cur_line++;
267 } /* end of while loop handling one hunk */
268 } /* end of while loop handling one file */
269
270 /* Cleanup last patched file */
271 if (copy_trailing_lines_flag) {
272 copy_lines(src_stream, dst_stream, (unsigned)(-1));
273 }
274 if (src_stream) {
275 fclose(src_stream);
276 }
277 fclose(dst_stream);
278 if (bad_hunk_count) {
279 ret = 1;
280 bb_error_msg("%u out of %u hunk FAILED", bad_hunk_count, hunk_count);
281 } else {
282 /* It worked, we can remove the backup */
283 if (backup_filename) {
284 unlink(backup_filename);
285 }
286 if (!(opt & OPT_dry_run)
287 && ((dst_cur_line == 0) || (dst_beg_line == 0))
288 ) {
289 /* The new patched file is empty, remove it */
290 xunlink(new_filename);
291 // /* old_filename and new_filename may be the same file */
292 // unlink(old_filename);
293 }
294 }
295 free(backup_filename);
296 //free(old_filename);
297 free(new_filename);
298 } /* end of "while there are patch lines" */
299 quit:
300 /* 0 = SUCCESS
301 * 1 = Some hunks failed
302 * 2 = More serious problems (exited earlier)
303 */
304 return ret;
305 }
306