arping: change a few message strings to be closer to iputils arping
[oweals/busybox.git] / networking / httpd_ssi.c
1 /*
2  * Copyright (c) 2009 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 processes server-side includes:
9  * <!--#include file="file.html" -->
10  *
11  * Usage: put these lines in httpd.conf:
12  *
13  * *.html:/bin/httpd_ssi
14  * *.htm:/bin/httpd_ssi
15  */
16
17 /* Build a-la
18 i486-linux-uclibc-gcc \
19 -static -static-libgcc \
20 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 \
21 -Wall -Wshadow -Wwrite-strings -Wundef -Wstrict-prototypes -Werror \
22 -Wold-style-definition -Wdeclaration-after-statement -Wno-pointer-sign \
23 -Wmissing-prototypes -Wmissing-declarations \
24 -Os -fno-builtin-strlen -finline-limit=0 -fomit-frame-pointer \
25 -ffunction-sections -fdata-sections -fno-guess-branch-probability \
26 -funsigned-char \
27 -falign-functions=1 -falign-jumps=1 -falign-labels=1 -falign-loops=1 \
28 -march=i386 -mpreferred-stack-boundary=2 \
29 -Wl,-Map -Wl,link.map -Wl,--warn-common -Wl,--sort-common -Wl,--gc-sections \
30 httpd_ssi.c -o httpd_ssi
31 */
32
33 /* Size (i386, static uclibc, approximate):
34  * text    data     bss     dec     hex filename
35  * 9487     160   68552   78199   13177 httpd_ssi
36  *
37  * Note: it wouldn't be too hard to get rid of stdio and strdup,
38  * (especially that fgets() mangles NULs...)
39  */
40
41 #include <sys/types.h>
42 #include <sys/stat.h>
43 #include <errno.h>
44 #include <fcntl.h>
45 #include <stdint.h>
46 #include <stdlib.h>
47 #include <string.h>
48 #include <unistd.h>
49 #include <stdio.h>
50 #include <dirent.h>
51 #include <time.h>
52
53 static char* skip_whitespace(char *s)
54 {
55         while (*s == ' ' || *s == '\t') ++s;
56
57         return s;
58 }
59
60 static char line[64 * 1024];
61
62 static void process_includes(const char *filename)
63 {
64         int curdir_fd;
65         char *end;
66         FILE *fp = fopen(filename, "r");
67         if (!fp)
68                 exit(1);
69
70         /* Ensure that nested includes are relative:
71          * if we include a/1.htm and it includes b/2.htm,
72          * we need to include a/b/2.htm, not b/2.htm
73          */
74         curdir_fd = -1;
75         end = strrchr(filename, '/');
76         if (end) {
77                 curdir_fd = open(".", O_RDONLY);
78                 /* *end = '\0' would mishandle "/file.htm" */
79                 end[1] = '\0';
80                 chdir(filename);
81         }
82
83 #define INCLUDE "<!--#include"
84         while (fgets(line, sizeof(line), fp)) {
85                 unsigned preceding_len;
86                 char *include_directive;
87
88                 include_directive = strstr(line, INCLUDE);
89                 if (!include_directive) {
90                         fputs(line, stdout);
91                         continue;
92                 }
93                 preceding_len = include_directive - line;
94                 if (memchr(line, '\"', preceding_len)
95                  || memchr(line, '\'', preceding_len)
96                 ) {
97                         /* INCLUDE string may be inside "str" or 'str',
98                          * ignore it */
99                         fputs(line, stdout);
100                         continue;
101                 }
102                 /* Small bug: we accept #includefile="file" too */
103                 include_directive = skip_whitespace(include_directive + sizeof(INCLUDE)-1);
104                 if (strncmp(include_directive, "file=\"", 6) != 0) {
105                         /* "<!--#include virtual=..."? - not supported */
106                         fputs(line, stdout);
107                         continue;
108                 }
109                 include_directive += 6; /* now it points to file name */
110                 end = strchr(include_directive, '\"');
111                 if (!end) {
112                         fputs(line, stdout);
113                         continue;
114                 }
115                 /* We checked that this is a valid include directive */
116
117                 /* Print everything before directive */
118                 if (preceding_len) {
119                         line[preceding_len] = '\0';
120                         fputs(line, stdout);
121                 }
122                 /* Save everything after directive */
123                 *end++ = '\0';
124                 end = strchr(end, '>');
125                 if (end)
126                         end = strdup(end + 1);
127
128                 /* FIXME:
129                  * (1) are relative paths with /../ etc ok?
130                  * (2) what to do with absolute paths?
131                  * are they relative to doc root or to real root?
132                  */
133                 process_includes(include_directive);
134
135                 /* Print everything after directive */
136                 if (end) {
137                         fputs(end, stdout);
138                         free(end);
139                 }
140         }
141         if (curdir_fd >= 0)
142                 fchdir(curdir_fd);
143         fclose(fp);
144 }
145
146 int main(int argc, char *argv[])
147 {
148         if (!argv[1])
149                 return 1;
150
151         /* Seen from busybox.net's Apache:
152          * HTTP/1.1 200 OK
153          * Date: Thu, 10 Sep 2009 18:23:28 GMT
154          * Server: Apache
155          * Accept-Ranges: bytes
156          * Connection: close
157          * Content-Type: text/html
158          */
159         fputs(
160                 /* "Date: Thu, 10 Sep 2009 18:23:28 GMT\r\n" */
161                 /* "Server: Apache\r\n" */
162                 /* "Accept-Ranges: bytes\r\n" - do we really accept bytes?! */
163                 "Connection: close\r\n"
164                 "Content-Type: text/html\r\n"
165                 "\r\n",
166                 stdout
167         );
168         process_includes(argv[1]);
169         return 0;
170 }