fix overlapping memcpy in normalize_absolute_path
[git] / entry.c
1 #include "cache.h"
2 #include "blob.h"
3
4 static void create_directories(const char *path, const struct checkout *state)
5 {
6         int len = strlen(path);
7         char *buf = xmalloc(len + 1);
8         const char *slash = path;
9
10         while ((slash = strchr(slash+1, '/')) != NULL) {
11                 struct stat st;
12                 int stat_status;
13
14                 len = slash - path;
15                 memcpy(buf, path, len);
16                 buf[len] = 0;
17
18                 if (len <= state->base_dir_len)
19                         /*
20                          * checkout-index --prefix=<dir>; <dir> is
21                          * allowed to be a symlink to an existing
22                          * directory.
23                          */
24                         stat_status = stat(buf, &st);
25                 else
26                         /*
27                          * if there currently is a symlink, we would
28                          * want to replace it with a real directory.
29                          */
30                         stat_status = lstat(buf, &st);
31
32                 if (!stat_status && S_ISDIR(st.st_mode))
33                         continue; /* ok, it is already a directory. */
34
35                 /*
36                  * We know stat_status == 0 means something exists
37                  * there and this mkdir would fail, but that is an
38                  * error codepath; we do not care, as we unlink and
39                  * mkdir again in such a case.
40                  */
41                 if (mkdir(buf, 0777)) {
42                         if (errno == EEXIST && state->force &&
43                             !unlink(buf) && !mkdir(buf, 0777))
44                                 continue;
45                         die("cannot create directory at %s", buf);
46                 }
47         }
48         free(buf);
49 }
50
51 static void remove_subtree(const char *path)
52 {
53         DIR *dir = opendir(path);
54         struct dirent *de;
55         char pathbuf[PATH_MAX];
56         char *name;
57
58         if (!dir)
59                 die("cannot opendir %s (%s)", path, strerror(errno));
60         strcpy(pathbuf, path);
61         name = pathbuf + strlen(path);
62         *name++ = '/';
63         while ((de = readdir(dir)) != NULL) {
64                 struct stat st;
65                 if ((de->d_name[0] == '.') &&
66                     ((de->d_name[1] == 0) ||
67                      ((de->d_name[1] == '.') && de->d_name[2] == 0)))
68                         continue;
69                 strcpy(name, de->d_name);
70                 if (lstat(pathbuf, &st))
71                         die("cannot lstat %s (%s)", pathbuf, strerror(errno));
72                 if (S_ISDIR(st.st_mode))
73                         remove_subtree(pathbuf);
74                 else if (unlink(pathbuf))
75                         die("cannot unlink %s (%s)", pathbuf, strerror(errno));
76         }
77         closedir(dir);
78         if (rmdir(path))
79                 die("cannot rmdir %s (%s)", path, strerror(errno));
80 }
81
82 static int create_file(const char *path, unsigned int mode)
83 {
84         mode = (mode & 0100) ? 0777 : 0666;
85         return open(path, O_WRONLY | O_CREAT | O_EXCL, mode);
86 }
87
88 static void *read_blob_entry(struct cache_entry *ce, const char *path, unsigned long *size)
89 {
90         enum object_type type;
91         void *new = read_sha1_file(ce->sha1, &type, size);
92
93         if (new) {
94                 if (type == OBJ_BLOB)
95                         return new;
96                 free(new);
97         }
98         return NULL;
99 }
100
101 static int write_entry(struct cache_entry *ce, char *path, const struct checkout *state, int to_tempfile)
102 {
103         int fd;
104         long wrote;
105
106         switch (ce->ce_mode & S_IFMT) {
107                 char *new;
108                 struct strbuf buf;
109                 unsigned long size;
110
111         case S_IFREG:
112                 new = read_blob_entry(ce, path, &size);
113                 if (!new)
114                         return error("git checkout-index: unable to read sha1 file of %s (%s)",
115                                 path, sha1_to_hex(ce->sha1));
116
117                 /*
118                  * Convert from git internal format to working tree format
119                  */
120                 strbuf_init(&buf, 0);
121                 if (convert_to_working_tree(ce->name, new, size, &buf)) {
122                         size_t newsize = 0;
123                         free(new);
124                         new = strbuf_detach(&buf, &newsize);
125                         size = newsize;
126                 }
127
128                 if (to_tempfile) {
129                         strcpy(path, ".merge_file_XXXXXX");
130                         fd = mkstemp(path);
131                 } else
132                         fd = create_file(path, ce->ce_mode);
133                 if (fd < 0) {
134                         free(new);
135                         return error("git checkout-index: unable to create file %s (%s)",
136                                 path, strerror(errno));
137                 }
138
139                 wrote = write_in_full(fd, new, size);
140                 close(fd);
141                 free(new);
142                 if (wrote != size)
143                         return error("git checkout-index: unable to write file %s", path);
144                 break;
145         case S_IFLNK:
146                 new = read_blob_entry(ce, path, &size);
147                 if (!new)
148                         return error("git checkout-index: unable to read sha1 file of %s (%s)",
149                                 path, sha1_to_hex(ce->sha1));
150                 if (to_tempfile || !has_symlinks) {
151                         if (to_tempfile) {
152                                 strcpy(path, ".merge_link_XXXXXX");
153                                 fd = mkstemp(path);
154                         } else
155                                 fd = create_file(path, 0666);
156                         if (fd < 0) {
157                                 free(new);
158                                 return error("git checkout-index: unable to create "
159                                                  "file %s (%s)", path, strerror(errno));
160                         }
161                         wrote = write_in_full(fd, new, size);
162                         close(fd);
163                         free(new);
164                         if (wrote != size)
165                                 return error("git checkout-index: unable to write file %s",
166                                         path);
167                 } else {
168                         wrote = symlink(new, path);
169                         free(new);
170                         if (wrote)
171                                 return error("git checkout-index: unable to create "
172                                                  "symlink %s (%s)", path, strerror(errno));
173                 }
174                 break;
175         case S_IFGITLINK:
176                 if (to_tempfile)
177                         return error("git checkout-index: cannot create temporary subproject %s", path);
178                 if (mkdir(path, 0777) < 0)
179                         return error("git checkout-index: cannot create subproject directory %s", path);
180                 break;
181         default:
182                 return error("git checkout-index: unknown file mode for %s", path);
183         }
184
185         if (state->refresh_cache) {
186                 struct stat st;
187                 lstat(ce->name, &st);
188                 fill_stat_cache_info(ce, &st);
189         }
190         return 0;
191 }
192
193 int checkout_entry(struct cache_entry *ce, const struct checkout *state, char *topath)
194 {
195         static char path[PATH_MAX + 1];
196         struct stat st;
197         int len = state->base_dir_len;
198
199         if (topath)
200                 return write_entry(ce, topath, state, 1);
201
202         memcpy(path, state->base_dir, len);
203         strcpy(path + len, ce->name);
204
205         if (!lstat(path, &st)) {
206                 unsigned changed = ce_match_stat(ce, &st, CE_MATCH_IGNORE_VALID);
207                 if (!changed)
208                         return 0;
209                 if (!state->force) {
210                         if (!state->quiet)
211                                 fprintf(stderr, "git-checkout-index: %s already exists\n", path);
212                         return -1;
213                 }
214
215                 /*
216                  * We unlink the old file, to get the new one with the
217                  * right permissions (including umask, which is nasty
218                  * to emulate by hand - much easier to let the system
219                  * just do the right thing)
220                  */
221                 if (S_ISDIR(st.st_mode)) {
222                         /* If it is a gitlink, leave it alone! */
223                         if (S_ISGITLINK(ce->ce_mode))
224                                 return 0;
225                         if (!state->force)
226                                 return error("%s is a directory", path);
227                         remove_subtree(path);
228                 } else if (unlink(path))
229                         return error("unable to unlink old '%s' (%s)", path, strerror(errno));
230         } else if (state->not_new)
231                 return 0;
232         create_directories(path, state);
233         return write_entry(ce, path, state, 0);
234 }