Modified callcgi to run CGI programs without an explicit handler.
[ashd.git] / src / callcgi.c
CommitLineData
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1/*
2 ashd - A Sane HTTP Daemon
3 Copyright (C) 2008 Fredrik Tolf <fredrik@dolda2000.com>
4
5 This program is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation, either version 3 of the License, or
8 (at your option) any later version.
9
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
14
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>.
17*/
18
19#include <stdlib.h>
20#include <string.h>
21#include <stdio.h>
22#include <unistd.h>
23#include <errno.h>
24#include <ctype.h>
25#include <signal.h>
26
27#ifdef HAVE_CONFIG_H
28#include <config.h>
29#endif
30#include <utils.h>
31#include <log.h>
32
33static char **environ;
34
35static void passdata(FILE *in, FILE *out)
36{
37 int ret;
38 char *buf;
39
40 buf = smalloc(65536);
41 while(!feof(in)) {
42 ret = fread(buf, 1, 65536, in);
43 if(ferror(in)) {
44 flog(LOG_ERR, "sendfile: could not read input: %s", strerror(errno));
45 break;
46 }
47 if(fwrite(buf, 1, ret, out) != ret) {
48 flog(LOG_ERR, "sendfile: could not write output: %s", strerror(errno));
49 break;
50 }
51 }
52 free(buf);
53}
54
341b3f0b 55static void forkchild(int inpath, char *prog, char *file, char *method, char *url, char *rest, int *infd, int *outfd)
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56{
57 int i;
58 char *qp, **env;
59 int inp[2], outp[2];
60 pid_t pid;
61
62 pipe(inp);
63 pipe(outp);
64 if((pid = fork()) < 0) {
65 flog(LOG_ERR, "callcgi: could not fork");
66 exit(1);
67 }
68 if(pid == 0) {
69 close(inp[1]);
70 close(outp[0]);
71 dup2(inp[0], 0);
72 dup2(outp[1], 1);
73 for(i = 3; i < FD_SETSIZE; i++)
74 close(i);
75 if((qp = strchr(url, '?')) != NULL)
76 *(qp++) = 0;
77 /*
78 * XXX: Currently missing:
79 * SERVER_NAME (Partially)
80 * SERVER_PORT
81 */
82 putenv(sprintf2("SERVER_SOFTWARE=ashd/%s", VERSION));
83 putenv("GATEWAY_INTERFACE=CGI/1.1");
84 if(getenv("HTTP_VERSION"))
85 putenv(sprintf2("SERVER_PROTOCOL=HTTP/%s", getenv("HTTP_VERSION")));
86 putenv(sprintf2("REQUEST_METHOD=%s", method));
87 putenv(sprintf2("PATH_INFO=%s", rest));
88 putenv(sprintf2("SCRIPT_NAME=%s", url));
89 putenv(sprintf2("QUERY_STRING=%s", qp?qp:""));
90 if(getenv("REQ_HOST"))
91 putenv(sprintf2("SERVER_NAME=%s", getenv("REQ_HOST")));
92 if(getenv("REQ_X_ASH_ADDRESS"))
93 putenv(sprintf2("REMOTE_ADDR=%s", getenv("REQ_X_ASH_ADDRESS")));
94 if(getenv("REQ_CONTENT_TYPE"))
95 putenv(sprintf2("CONTENT_TYPE=%s", getenv("REQ_CONTENT_TYPE")));
96 if(getenv("REQ_CONTENT_LENGTH"))
97 putenv(sprintf2("CONTENT_LENGTH=%s", getenv("REQ_CONTENT_LENGTH")));
98 for(env = environ; *env; env++) {
99 if(!strncmp(*env, "REQ_", 4))
100 putenv(sprintf2("HTTP_%s", (*env) + 4));
101 }
102 /*
103 * This is (understandably) missing from the CGI
104 * specification, but PHP seems to require it.
105 */
106 putenv(sprintf2("SCRIPT_FILENAME=%s", file));
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107 if(inpath)
108 execlp(prog, prog, file, NULL);
109 else
110 execl(prog, prog, file, NULL);
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111 exit(127);
112 }
113 close(inp[0]);
114 close(outp[1]);
115 *infd = inp[1];
116 *outfd = outp[0];
117}
118
119static void trim(struct charbuf *buf)
120{
121 char *p;
122
123 for(p = buf->b; (p - buf->b < buf->d) && isspace(*p); p++);
124 memmove(buf->b, p, buf->d -= (p - buf->b));
125 for(p = buf->b + buf->d - 1; (p > buf->b) && isspace(*p); p--, buf->d--);
126}
127
128static char **parseheaders(FILE *s)
129{
130 int c, state;
131 struct charvbuf hbuf;
132 struct charbuf buf;
133
134 bufinit(hbuf);
135 bufinit(buf);
136 state = 0;
137 while(1) {
138 c = fgetc(s);
139 again:
140 if(state == 0) {
141 if(c == '\r') {
142 } else if(c == '\n') {
143 break;
144 } else if(c == EOF) {
145 goto fail;
146 } else {
147 state = 1;
148 goto again;
149 }
150 } else if(state == 1) {
151 if(c == ':') {
152 trim(&buf);
153 bufadd(buf, 0);
154 bufadd(hbuf, buf.b);
155 bufinit(buf);
156 state = 2;
157 } else if(c == '\r') {
158 } else if(c == '\n') {
159 goto fail;
160 } else if(c == EOF) {
161 goto fail;
162 } else {
163 bufadd(buf, c);
164 }
165 } else if(state == 2) {
166 if(c == '\r') {
167 } else if(c == '\n') {
168 trim(&buf);
169 bufadd(buf, 0);
170 bufadd(hbuf, buf.b);
171 bufinit(buf);
172 state = 0;
173 } else if(c == EOF) {
174 goto fail;
175 } else {
176 bufadd(buf, c);
177 }
178 }
179 }
180 bufadd(hbuf, NULL);
181 return(hbuf.b);
182
183fail:
184 buffree(hbuf);
185 buffree(buf);
186 return(NULL);
187}
188
189static void sendstatus(char **headers, FILE *out)
190{
191 char **hp;
192 char *status, *location;
193
194 hp = headers;
195 status = location = NULL;
196 while(*hp) {
197 if(!strcasecmp(hp[0], "status")) {
198 status = hp[1];
199 /* Clear this header, so that it is not transmitted by sendheaders. */
200 **hp = 0;
201 } else if(!strcasecmp(hp[0], "location")) {
202 location = hp[1];
203 } else {
204 hp += 2;
205 }
206 }
207 if(status) {
208 fprintf(out, "HTTP/1.1 %s\r\n", status);
209 } else if(location) {
210 fprintf(out, "HTTP/1.1 303 See Other\r\n");
211 } else {
212 fprintf(out, "HTTP/1.1 200 OK\r\n");
213 }
214}
215
216static void sendheaders(char **headers, FILE *out)
217{
218 while(*headers) {
219 if(**headers)
220 fprintf(out, "%s: %s\r\n", headers[0], headers[1]);
221 headers += 2;
222 }
223}
224
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225static void usage(void)
226{
227 flog(LOG_ERR, "usage: callcgi [-p PROGRAM] METHOD URL REST");
228}
229
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230int main(int argc, char **argv, char **envp)
231{
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232 int c;
233 char *file, *prog;
234 int inpath;
235 int infd, outfd;
236 FILE *in, *out;
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237 char **headers;
238
239 environ = envp;
240 signal(SIGPIPE, SIG_IGN);
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241
242 prog = NULL;
243 inpath = 0;
244 while((c = getopt(argc, argv, "p:")) >= 0) {
245 switch(c) {
246 case 'p':
247 prog = optarg;
248 inpath = 1;
249 break;
250 default:
251 usage();
252 exit(1);
253 }
254 }
255
256 if(argc - optind < 3) {
257 usage();
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258 exit(1);
259 }
260 if((file = getenv("REQ_X_ASH_FILE")) == NULL) {
261 flog(LOG_ERR, "callcgi: needs to be called with the X-Ash-File header");
262 exit(1);
263 }
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264 if(prog == NULL)
265 prog = file;
266 forkchild(inpath, prog, file, argv[optind], argv[optind + 1], argv[optind + 2], &infd, &outfd);
267 in = fdopen(infd, "w");
268 passdata(stdin, in);
269 fclose(in);
270 out = fdopen(outfd, "r");
271 if((headers = parseheaders(out)) == NULL) {
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272 flog(LOG_WARNING, "CGI handler returned invalid headers");
273 exit(1);
274 }
275 sendstatus(headers, stdout);
276 sendheaders(headers, stdout);
277 printf("\r\n");
341b3f0b 278 passdata(out, stdout);
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279 return(0);
280}