eris/cgi.c

188 lines
5.0 KiB
C

void
sigchld(int sig)
{
while (waitpid(0, NULL, WNOHANG) > 0);
}
static void
cgi_child(const char *relpath)
{
setenv("GATEWAY_INTERFACE", "CGI/1.1", 1);
setenv("SERVER_SOFTWARE", FNORD, 1);
setenv("REQUEST_URI", path, 1);
setenv("SERVER_NAME", host, 1);
setenv("SCRIPT_NAME", relpath, 1);
setenv("REMOTE_ADDR", remote_ip, 1);
setenv("REMOTE_PORT", remote_port, 1);
setenv("REMOTE_IDENT", remote_ident, 1);
if (content_length) {
char cl[20];
snprintf(cl, sizeof cl, "%llu", (unsigned long long) content_length);
setenv("CONTENT_LENGTH", cl, 1);
setenv("CONTENT_TYPE", content_type, 1);
}
execl(relpath, relpath, NULL);
exit(1);
}
void
cgi_parent(int cin, int cout, int passthru)
{
char cgiheader[BUFFER_SIZE];
size_t cgiheaderlen = 0;
FILE *cinf = fdopen(cin, "rb");
size_t size = 0;
int header_sent = 0;
fcntl(cin, F_SETFL, O_NONBLOCK);
signal(SIGCHLD, sigchld);
signal(SIGPIPE, SIG_IGN); /* NO! no signal! */
while (1) {
int nfds;
fd_set rfds, wfds;
FD_ZERO(&rfds);
FD_ZERO(&wfds);
FD_SET(cin, &rfds);
nfds = cin;
if (content_length) {
/* have post data */
FD_SET(cout, &wfds);
if (cout > nfds) {
nfds = cout;
}
} else if (cout >= 0) {
close(cout); /* no post data */
cout = -1;
}
if (-1 == select(nfds+1, &rfds, &wfds, NULL, NULL)) {
break;
}
if (FD_ISSET(cin, &rfds)) {
if (passthru) {
/* Pass everything through verbatim */
size_t len;
/* Re-use this big buffer */
len = fread(cgiheader, 1, sizeof cgiheader, cinf);
if (0 == len) {
/* CGI is done */
break;
}
fwrite(cgiheader, 1, len, stdout);
size += len;
} else {
/* Interpret header fields */
size_t readlen = (sizeof cgiheader) - cgiheaderlen;
if (NULL == fgets(cgiheader + cgiheaderlen, readlen, cinf)) {
/* EOF or error */
badrequest(500, "CGI Error", "CGI output too weird");
}
cgiheaderlen = strlen(cgiheader);
if ('\n' == cgiheader[cgiheaderlen - 1]) {
/* We read a whole line */
size_t len;
char *val;
len = extract_header_field(cgiheader, &val, 0);
if (! len) {
/* We've read the entire header block */
passthru = 1;
eoh();
} else {
if (! header_sent) {
if (! strcasecmp(cgiheader, "Location")) {
header(302, "CGI Redirect");
fwrite(cgiheader, 1, cgiheaderlen, stdout);
dolog(302, 0);
exit(0);
}
header(200, "OK");
printf("Pragma: no-cache\r\n");
header_sent = 1;
}
printf("%s: %s\r\n", cgiheader, val);
cgiheaderlen = 0;
}
}
}
} else if (FD_ISSET(cout, &wfds)) {
/*
* write to cgi the post data
*/
if (content_length) {
size_t len;
char buf[BUFFER_SIZE];
size_t nmemb = min(BUFFER_SIZE, content_length);
len = fread(buf, 1, nmemb, stdin);
if (len < 1) {
break;
}
content_length -= len;
write(cout, buf, len);
} else {
close(cout);
}
}
}
fflush(stdout);
dolog(200, size);
cork(0);
}
void
serve_cgi(char *relpath)
{
int pid;
int cin[2];
int cout[2];
if (pipe(cin) || pipe(cout)) {
badrequest(500, "Internal Server Error", "Server Resource problem.");
}
pid = fork();
if (-1 == pid) {
badrequest(500, "Internal Server Error", "Unable to fork.");
}
if (pid) {
close(cin[1]);
close(cout[0]);
/* Eris is not this smart yet */
keepalive = 0;
alarm(CGI_TIMEOUT);
cgi_parent(cin[0], cout[1], 0);
alarm(0);
exit(0);
} else {
close(cwd);
close(cout[1]);
close(cin[0]);
dup2(cout[0], 0);
dup2(cin[1], 1);
close(cout[0]);
close(cin[1]);
cgi_child(relpath);
}
}