wget: attempt to negotiate encrypted data ftps stream ("PROT P")
[oweals/busybox.git] / networking / httpd_indexcgi.c
1 /*
2  * Copyright (c) 2007 Denys Vlasenko <vda.linux@googlemail.com>
3  *
4  * Licensed under GPLv2, see file LICENSE in this source tree.
5  */
6
7 /*
8  * This program is a CGI application. It outputs directory index page.
9  * Put it into cgi-bin/index.cgi and chmod 0755.
10  */
11
12 /* Build a-la
13 i486-linux-uclibc-gcc \
14 -static -static-libgcc \
15 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 \
16 -Wall -Wshadow -Wwrite-strings -Wundef -Wstrict-prototypes -Werror \
17 -Wold-style-definition -Wdeclaration-after-statement -Wno-pointer-sign \
18 -Wmissing-prototypes -Wmissing-declarations \
19 -Os -fno-builtin-strlen -finline-limit=0 -fomit-frame-pointer \
20 -ffunction-sections -fdata-sections -fno-guess-branch-probability \
21 -funsigned-char \
22 -falign-functions=1 -falign-jumps=1 -falign-labels=1 -falign-loops=1 \
23 -march=i386 -mpreferred-stack-boundary=2 \
24 -Wl,-Map -Wl,link.map -Wl,--warn-common -Wl,--sort-common -Wl,--gc-sections \
25 httpd_indexcgi.c -o index.cgi
26 */
27
28 /* We don't use printf, as it pulls in >12 kb of code from uclibc (i386). */
29 /* Currently malloc machinery is the biggest part of libc we pull in. */
30 /* We have only one realloc and one strdup, any idea how to do without? */
31
32 /* Size (i386, static uclibc, approximate):
33  *   text    data     bss     dec     hex filename
34  *  13036      44    3052   16132    3f04 index.cgi
35  *   2576       4    2048    4628    1214 index.cgi.o
36  */
37
38 #define _GNU_SOURCE 1  /* for strchrnul */
39 #include <sys/types.h>
40 #include <sys/stat.h>
41 #include <errno.h>
42 #include <stdint.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <unistd.h>
46 #include <stdio.h>
47 #include <dirent.h>
48 #include <time.h>
49
50 /* Appearance of the table is controlled by style sheet *ONLY*,
51  * formatting code uses <TAG class=CLASS> to apply style
52  * to elements. Edit stylesheet to your liking and recompile. */
53
54 #define STYLE_STR \
55 "<style>"                                               "\n"\
56 "table {"                                               "\n"\
57   "width:100%;"                                         "\n"\
58   "background-color:#fff5ee;"                           "\n"\
59   "border-width:1px;" /* 1px 1px 1px 1px; */            "\n"\
60   "border-spacing:2px;"                                 "\n"\
61   "border-style:solid;" /* solid solid solid solid; */  "\n"\
62   "border-color:black;" /* black black black black; */  "\n"\
63   "border-collapse:collapse;"                           "\n"\
64 "}"                                                     "\n"\
65 "th {"                                                  "\n"\
66   "border-width:1px;" /* 1px 1px 1px 1px; */            "\n"\
67   "padding:1px;" /* 1px 1px 1px 1px; */                 "\n"\
68   "border-style:solid;" /* solid solid solid solid; */  "\n"\
69   "border-color:black;" /* black black black black; */  "\n"\
70 "}"                                                     "\n"\
71 "td {"                                                  "\n"\
72              /* top right bottom left */                    \
73   "border-width:0px 1px 0px 1px;"                       "\n"\
74   "padding:1px;" /* 1px 1px 1px 1px; */                 "\n"\
75   "border-style:solid;" /* solid solid solid solid; */  "\n"\
76   "border-color:black;" /* black black black black; */  "\n"\
77   "white-space:nowrap;"                                 "\n"\
78 "}"                                                     "\n"\
79 "tr.hdr { background-color:#eee5de; }"                  "\n"\
80 "tr.o { background-color:#ffffff; }"                    "\n"\
81 /* tr.e { ... } - for even rows (currently none) */         \
82 "tr.foot { background-color:#eee5de; }"                 "\n"\
83 "th.cnt { text-align:left; }"                           "\n"\
84 "th.sz { text-align:right; }"                           "\n"\
85 "th.dt { text-align:right; }"                           "\n"\
86 "td.sz { text-align:right; }"                           "\n"\
87 "td.dt { text-align:right; }"                           "\n"\
88 "col.nm { width:98%; }"                                 "\n"\
89 "col.sz { width:1%; }"                                  "\n"\
90 "col.dt { width:1%; }"                                  "\n"\
91 "</style>"                                              "\n"\
92
93 typedef struct dir_list_t {
94         char  *dl_name;
95         mode_t dl_mode;
96         off_t  dl_size;
97         time_t dl_mtime;
98 } dir_list_t;
99
100 static int compare_dl(dir_list_t *a, dir_list_t *b)
101 {
102         /* ".." is 'less than' any other dir entry */
103         if (strcmp(a->dl_name, "..") == 0) {
104                 return -1;
105         }
106         if (strcmp(b->dl_name, "..") == 0) {
107                 return 1;
108         }
109         if (S_ISDIR(a->dl_mode) != S_ISDIR(b->dl_mode)) {
110                 /* 1 if b is a dir (and thus a is 'after' b, a > b),
111                  * else -1 (a < b) */
112                 return (S_ISDIR(b->dl_mode) != 0) ? 1 : -1;
113         }
114         return strcmp(a->dl_name, b->dl_name);
115 }
116
117 static char buffer[2*1024 > sizeof(STYLE_STR) ? 2*1024 : sizeof(STYLE_STR)];
118 static char *dst = buffer;
119 enum {
120         BUFFER_SIZE = sizeof(buffer),
121         HEADROOM = 64,
122 };
123
124 /* After this call, you have at least size + HEADROOM bytes available
125  * ahead of dst */
126 static void guarantee(int size)
127 {
128         if (buffer + (BUFFER_SIZE-HEADROOM) - dst >= size)
129                 return;
130         write(STDOUT_FILENO, buffer, dst - buffer);
131         dst = buffer;
132 }
133
134 /* NB: formatters do not store terminating NUL! */
135
136 /* HEADROOM bytes are available after dst after this call */
137 static void fmt_str(/*char *dst,*/ const char *src)
138 {
139         unsigned len = strlen(src);
140         guarantee(len);
141         memcpy(dst, src, len);
142         dst += len;
143 }
144
145 /* HEADROOM bytes after dst are available after this call */
146 static void fmt_url(/*char *dst,*/ const char *name)
147 {
148         while (*name) {
149                 unsigned c = *name++;
150                 guarantee(3);
151                 *dst = c;
152                 if ((c - '0') > 9 /* not a digit */
153                  && ((c|0x20) - 'a') > ('z' - 'a') /* not A-Z or a-z */
154                  && !strchr("._-+@", c)
155                 ) {
156                         *dst++ = '%';
157                         *dst++ = "0123456789ABCDEF"[c >> 4];
158                         *dst = "0123456789ABCDEF"[c & 0xf];
159                 }
160                 dst++;
161         }
162 }
163
164 /* HEADROOM bytes are available after dst after this call */
165 static void fmt_html(/*char *dst,*/ const char *name)
166 {
167         while (*name) {
168                 char c = *name++;
169                 if (c == '<')
170                         fmt_str("&lt;");
171                 else if (c == '>')
172                         fmt_str("&gt;");
173                 else if (c == '&') {
174                         fmt_str("&amp;");
175                 } else {
176                         guarantee(1);
177                         *dst++ = c;
178                         continue;
179                 }
180         }
181 }
182
183 /* HEADROOM bytes are available after dst after this call */
184 static void fmt_ull(/*char *dst,*/ unsigned long long n)
185 {
186         char buf[sizeof(n)*3 + 2];
187         char *p;
188
189         p = buf + sizeof(buf) - 1;
190         *p = '\0';
191         do {
192                 *--p = (n % 10) + '0';
193                 n /= 10;
194         } while (n);
195         fmt_str(/*dst,*/ p);
196 }
197
198 /* Does not call guarantee - eats into headroom instead */
199 static void fmt_02u(/*char *dst,*/ unsigned n)
200 {
201         /* n %= 100; - not needed, callers don't pass big n */
202         dst[0] = (n / 10) + '0';
203         dst[1] = (n % 10) + '0';
204         dst += 2;
205 }
206
207 /* Does not call guarantee - eats into headroom instead */
208 static void fmt_04u(/*char *dst,*/ unsigned n)
209 {
210         /* n %= 10000; - not needed, callers don't pass big n */
211         fmt_02u(n / 100);
212         fmt_02u(n % 100);
213 }
214
215 int main(int argc, char *argv[])
216 {
217         dir_list_t *dir_list;
218         dir_list_t *cdir;
219         unsigned dir_list_count;
220         unsigned count_dirs;
221         unsigned count_files;
222         unsigned long long size_total;
223         int odd;
224         DIR *dirp;
225         char *location;
226
227         location = getenv("REQUEST_URI");
228         if (!location)
229                 return 1;
230
231         /* drop URL arguments if any */
232         strchrnul(location, '?')[0] = '\0';
233
234         if (location[0] != '/'
235          || strstr(location, "//")
236          || strstr(location, "/../")
237          || strcmp(strrchr(location, '/'), "/..") == 0
238         ) {
239                 return 1;
240         }
241
242         if (chdir("..")
243          || (location[1] && chdir(location + 1))
244         ) {
245                 return 1;
246         }
247
248         dirp = opendir(".");
249         if (!dirp)
250                 return 1;
251         dir_list = NULL;
252         dir_list_count = 0;
253         while (1) {
254                 struct dirent *dp;
255                 struct stat sb;
256
257                 dp = readdir(dirp);
258                 if (!dp)
259                         break;
260                 if (dp->d_name[0] == '.' && !dp->d_name[1])
261                         continue;
262                 if (stat(dp->d_name, &sb) != 0)
263                         continue;
264                 dir_list = realloc(dir_list, (dir_list_count + 1) * sizeof(dir_list[0]));
265                 dir_list[dir_list_count].dl_name = strdup(dp->d_name);
266                 dir_list[dir_list_count].dl_mode = sb.st_mode;
267                 dir_list[dir_list_count].dl_size = sb.st_size;
268                 dir_list[dir_list_count].dl_mtime = sb.st_mtime;
269                 dir_list_count++;
270         }
271         closedir(dirp);
272
273         qsort(dir_list, dir_list_count, sizeof(dir_list[0]), (void*)compare_dl);
274
275         fmt_str(
276                 "" /* Additional headers (currently none) */
277                 "\r\n" /* Mandatory empty line after headers */
278                 "<html><head><title>Index of ");
279         /* Guard against directories with &, > etc */
280         fmt_html(location);
281         fmt_str(
282                 "</title>\n"
283                 STYLE_STR
284                 "</head>" "\n"
285                 "<body>" "\n"
286                 "<h1>Index of ");
287         fmt_html(location);
288         fmt_str(
289                 "</h1>" "\n"
290                 "<table>" "\n"
291                 "<col class=nm><col class=sz><col class=dt>" "\n"
292                 "<tr class=hdr><th class=cnt>Name<th class=sz>Size<th class=dt>Last modified" "\n");
293
294         odd = 0;
295         count_dirs = 0;
296         count_files = 0;
297         size_total = 0;
298         cdir = dir_list;
299         while (dir_list_count--) {
300                 struct tm *ptm;
301
302                 if (S_ISDIR(cdir->dl_mode)) {
303                         count_dirs++;
304                 } else if (S_ISREG(cdir->dl_mode)) {
305                         count_files++;
306                         size_total += cdir->dl_size;
307                 } else
308                         goto next;
309
310                 fmt_str("<tr class=");
311                 *dst++ = (odd ? 'o' : 'e');
312                 fmt_str("><td class=nm><a href='");
313                 fmt_url(cdir->dl_name); /* %20 etc */
314                 if (S_ISDIR(cdir->dl_mode))
315                         *dst++ = '/';
316                 fmt_str("'>");
317                 fmt_html(cdir->dl_name); /* &lt; etc */
318                 if (S_ISDIR(cdir->dl_mode))
319                         *dst++ = '/';
320                 fmt_str("</a><td class=sz>");
321                 if (S_ISREG(cdir->dl_mode))
322                         fmt_ull(cdir->dl_size);
323                 fmt_str("<td class=dt>");
324                 ptm = gmtime(&cdir->dl_mtime);
325                 fmt_04u(1900 + ptm->tm_year); *dst++ = '-';
326                 fmt_02u(ptm->tm_mon + 1); *dst++ = '-';
327                 fmt_02u(ptm->tm_mday); *dst++ = ' ';
328                 fmt_02u(ptm->tm_hour); *dst++ = ':';
329                 fmt_02u(ptm->tm_min); *dst++ = ':';
330                 fmt_02u(ptm->tm_sec);
331                 *dst++ = '\n';
332
333                 odd = 1 - odd;
334  next:
335                 cdir++;
336         }
337
338         fmt_str("<tr class=foot><th class=cnt>Files: ");
339         fmt_ull(count_files);
340         /* count_dirs - 1: we don't want to count ".." */
341         fmt_str(", directories: ");
342         fmt_ull(count_dirs - 1);
343         fmt_str("<th class=sz>");
344         fmt_ull(size_total);
345         fmt_str("<th class=dt>\n");
346         /* "</table></body></html>" - why bother? */
347         guarantee(BUFFER_SIZE * 2); /* flush */
348
349         return 0;
350 }