/*
* Print hURL redirect page
*/
void url_redirect(state *st)
{
char dest[BUFSIZE];
char *c;
/* Basic security checking */
sstrlcpy(dest, st->req_selector + 4);
if (sstrncmp(dest, "http://") != MATCH &&
sstrncmp(dest, "ftp://") != MATCH &&
sstrncmp(dest, "mailto:") != MATCH)
die(st, ERR_ACCESS, "Refusing to HTTP redirect unsafe protocols");
if ((c = strchr(dest, '"'))) *c = '\0';
if ((c = strchr(dest, '?'))) *c = '\0';
/* Log the redirect */
if (st->opt_syslog) {
syslog(LOG_INFO, "request for \"gopher://%s:%i/h%s\" from %s",
st->server_host,
st->server_port,
st->req_selector,
st->req_remote_addr);
}
log_combined(st, HTTP_OK);
/* Output HTML */
printf("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 3.2 Final//EN\">\n"
"<HTML>\n<HEAD>\n"
" <META HTTP-EQUIV=\"Refresh\" content=\"1;URL=%1$s\">\n"
" <META HTTP-EQUIV=\"Content-Type\" CONTENT=\"text/html;charset=iso-8859-1\">\n"
" <TITLE>URL Redirect page</TITLE>\n"
"</HEAD>\n<BODY>\n"
"<STRONG>Redirecting to <A HREF=\"%1$s\">%1$s</A></STRONG>\n"
"<PRE>\n", dest);
footer(st);
printf("</PRE>\n</BODY>\n</HTML>\n");
}
main()
{
char s[100],t[100];
int n,k;
printf("Enter Two Strings : ");
scanf("%s%s",s,t);
printf("Enter Value for n : ");
scanf("%d",&n);
k=sstrncmp(s,t,n);
if(k==0)
printf("\nThe strings are equal\n");
else
printf("\nThe strings are not equal\n");
// sstrncpy(s,t,n);
// printf("\nThe Copied String from %s to %s\n",t,s);
// sstrncat(s,t,n);
// printf("\nThe concatenated strings %s\n",s);
}
/*
* Get remote peer IP address
*/
char *get_peer_address(void)
{
#ifdef HAVE_IPv4
struct sockaddr_in addr;
socklen_t addrsize = sizeof(addr);
#endif
#ifdef HAVE_IPv6
struct sockaddr_in6 addr6;
socklen_t addr6size = sizeof(addr6);
static char address[INET6_ADDRSTRLEN];
#endif
char *c;
/* Are we a CGI script? */
if ((c = getenv("REMOTE_ADDR"))) return c;
/* if ((c = getenv("REMOTE_HOST"))) return c; */
/* Try IPv4 first */
#ifdef HAVE_IPv4
if (getpeername(0, (struct sockaddr *) &addr, &addrsize) == OK) {
c = inet_ntoa(addr.sin_addr);
if (strlen(c) > 0 && *c != '0') return c;
}
#endif
/* IPv4 didn't work - try IPv6 */
#ifdef HAVE_IPv6
if (getpeername(0, (struct sockaddr *) &addr6, &addr6size) == OK) {
if (inet_ntop(AF_INET6, &addr6.sin6_addr, address, sizeof(address))) {
/* Strip ::ffff: IPv4-in-IPv6 prefix */
if (sstrncmp(address, "::ffff:") == MATCH) return (address + 7);
else return address;
}
}
#endif
/* Nothing works... I'm out of ideas */
return DEFAULT_ADDR;
}
/* compare strings */
static int scompare(char *buff1, const char *buff2)
{
int i;
if (sstrlen(buff1) == sstrlen(buff2)) {
if (sstrcmp(buff1,buff2) == 0) {
if (fgets(buff1,4095,fp)==NULL) return -1;
return 0;
}
return -1;
}
for (i=0;i<sstrlen(buff1)-sstrlen(buff2);i++) {
if (buff1[i]==' ' || buff1[i]=='\t') {
continue;
}
else if ((sstrncmp(&buff1[i],buff2,sstrlen(buff2))==0)
&&((buff1[i+strlen(buff2)]==' ')||(buff1[i+strlen(buff2)]=='\t')||(buff1[i+strlen(buff2)]=='\n'))) {
return i+strlen(buff2);
}
else return -1;
}
return -1;
}
/*
* Main
*/
int main(int argc, char *argv[])
{
struct stat file;
state st;
char self[64];
char selector[BUFSIZE];
char buf[BUFSIZE];
char *dest;
char *c;
#ifdef HAVE_SHMEM
struct shmid_ds shm_ds;
shm_state *shm;
int shmid;
#endif
/* Get the name of this binary */
if ((c = strrchr(argv[0], '/'))) sstrlcpy(self, c + 1);
else sstrlcpy(self, argv[0]);
/* Initialize state */
#ifdef HAVE_LOCALES
setlocale(LC_TIME, DATE_LOCALE);
#endif
init_state(&st);
srand(time(NULL) / (getpid() + getppid()));
/* Handle command line arguments */
parse_args(&st, argc, argv);
/* Open syslog() */
if (st.opt_syslog) openlog(self, LOG_PID, LOG_DAEMON);
/* Make sure the computer is turned on */
#ifdef __HAIKU__
if (is_computer_on() != TRUE)
die(&st, ERR_ACCESS, "Please turn on the computer first");
#endif
/* Refuse to run as root */
#ifdef HAVE_PASSWD
if (st.opt_root && getuid() == 0)
die(&st, ERR_ACCESS, "Refusing to run as root");
#endif
/* Try to get shared memory */
#ifdef HAVE_SHMEM
if ((shmid = shmget(SHM_KEY, sizeof(shm_state), IPC_CREAT | SHM_MODE)) == ERROR) {
/* Getting memory failed -> delete the old allocation */
shmctl(shmid, IPC_RMID, &shm_ds);
shm = NULL;
}
else {
/* Map shared memory */
if ((shm = (shm_state *) shmat(shmid, (void *) 0, 0)) == (void *) ERROR)
shm = NULL;
/* Initialize mapped shared memory */
if (shm && shm->start_time == 0) {
shm->start_time = time(NULL);
/* Keep server platform & description in shm */
platform(&st);
sstrlcpy(shm->server_platform, st.server_platform);
sstrlcpy(shm->server_description, st.server_description);
}
}
/* For debugging shared memory issues */
if (!st.opt_shm) shm = NULL;
/* Get server platform and description */
if (shm) {
sstrlcpy(st.server_platform, shm->server_platform);
if (!*st.server_description)
sstrlcpy(st.server_description, shm->server_description);
}
else
#endif
platform(&st);
/* Read selector */
if (fgets(selector, sizeof(selector) - 1, stdin) == NULL)
selector[0] = '\0';
/* Remove trailing CRLF */
chomp(selector);
if (st.debug) syslog(LOG_INFO, "client sent us \"%s\"", selector);
/* Handle hURL: redirect page */
if (sstrncmp(selector, "URL:") == MATCH) {
st.req_filetype = TYPE_HTML;
sstrlcpy(st.req_selector, selector);
url_redirect(&st);
return OK;
}
/* Handle gopher+ root requests (UMN gopher client is seriously borken) */
if (sstrncmp(selector, "\t$") == MATCH) {
printf("+-1" CRLF);
printf("+INFO: 1Main menu\t\t%s\t%i" CRLF,
st.server_host,
st.server_port);
printf("+VIEWS:" CRLF " application/gopher+-menu: <512b>" CRLF);
printf("." CRLF);
if (st.debug) syslog(LOG_INFO, "got a request for gopher+ root menu");
return OK;
}
/* Convert HTTP request to gopher (respond using headerless HTTP/0.9) */
if (sstrncmp(selector, "GET ") == MATCH ||
sstrncmp(selector, "POST ") == MATCH ) {
if ((c = strchr(selector, ' '))) sstrlcpy(selector, c + 1);
if ((c = strchr(selector, ' '))) *c = '\0';
st.req_protocol = PROTO_HTTP;
if (st.debug) syslog(LOG_INFO, "got HTTP request for \"%s\"", selector);
}
/* Save default server_host & fetch session data (including new server_host) */
sstrlcpy(st.server_host_default, st.server_host);
#ifdef HAVE_SHMEM
if (shm) get_shm_session(&st, shm);
#endif
/* Loop through the selector, fix it & separate query_string */
dest = st.req_selector;
if (selector[0] != '/') *dest++ = '/';
for (c = selector; *c;) {
/* Skip duplicate slashes and /./ */
while (*c == '/' && *(c + 1) == '/') c++;
if (*c == '/' && *(c + 1) == '.' && *(c + 2) == '/') c += 2;
/* Start of a query string (either type 7 or HTTP-style)? */
if (*c == '\t' || (st.opt_query && *c == '?')) {
sstrlcpy(st.req_query_string, c + 1);
if ((c = strchr(st.req_query_string, '\t'))) *c = '\0';
break;
}
/* Start of virtual host hint? */
if (*c == ';') {
if (st.opt_vhost) sstrlcpy(st.server_host, c + 1);
/* Skip vhost on selector */
while (*c && *c != '\t') c++;
continue;
}
/* Copy valid char */
*dest++ = *c++;
}
*dest = '\0';
/* Remove encodings from selector */
strndecode(st.req_selector, st.req_selector, sizeof(st.req_selector));
/* Deny requests for Slashdot and /../ hackers */
if (strstr(st.req_selector, "/."))
die(&st, ERR_ACCESS, "Refusing to serve out dotfiles");
/* Handle /server-status requests */
#ifdef HAVE_SHMEM
if (sstrncmp(st.req_selector, SERVER_STATUS) == MATCH) {
if (shm) server_status(&st, shm, shmid);
return OK;
}
#endif
/* Remove possible extra cruft from server_host */
if ((c = strchr(st.server_host, '\t'))) *c = '\0';
/* Guess request filetype so we can die() with style... */
st.req_filetype = gopher_filetype(&st, st.req_selector, FALSE);
/* Convert seletor to path & stat() */
selector_to_path(&st);
if (st.debug) syslog(LOG_INFO, "path to resource is \"%s\"", st.req_realpath);
if (stat(st.req_realpath, &file) == ERROR) {
/* Handle virtual /caps.txt requests */
if (st.opt_caps && sstrncmp(st.req_selector, CAPS_TXT) == MATCH) {
#ifdef HAVE_SHMEM
caps_txt(&st, shm);
#else
caps_txt(&st, NULL);
#endif
return OK;
}
/* Requested file not found - die() */
die(&st, ERR_NOTFOUND, NULL);
}
/* Fetch request filesize from stat() */
st.req_filesize = file.st_size;
/* Everyone must have read access but no write access */
if ((file.st_mode & S_IROTH) == 0)
die(&st, ERR_ACCESS, "File or directory not world-readable");
if ((file.st_mode & S_IWOTH) != 0)
die(&st, ERR_ACCESS, "File or directory world-writeable");
/* If stat said it was a dir then it's a menu */
if ((file.st_mode & S_IFMT) == S_IFDIR) st.req_filetype = TYPE_MENU;
/* Not a dir - let's guess the filetype again... */
else if ((file.st_mode & S_IFMT) == S_IFREG)
st.req_filetype = gopher_filetype(&st, st.req_realpath, st.opt_magic);
/* Menu selectors must end with a slash */
if (st.req_filetype == TYPE_MENU && strlast(st.req_selector) != '/')
sstrlcat(st.req_selector, "/");
/* Change directory to wherever the resource was */
sstrlcpy(buf, st.req_realpath);
if ((file.st_mode & S_IFMT) != S_IFDIR) c = dirname(buf);
else c = buf;
if (chdir(c) == ERROR) die(&st, ERR_ACCESS, NULL);
/* Keep count of hits and data transfer */
#ifdef HAVE_SHMEM
if (shm) {
shm->hits++;
shm->kbytes += st.req_filesize / 1024;
/* Update user session */
update_shm_session(&st, shm);
}
#endif
/* Log the request */
if (st.opt_syslog) {
syslog(LOG_INFO, "request for \"gopher://%s:%i/%c%s\" from %s",
st.server_host,
st.server_port,
st.req_filetype,
st.req_selector,
st.req_remote_addr);
}
/* Check file type & act accordingly */
switch (file.st_mode & S_IFMT) {
case S_IFDIR:
log_combined(&st, HTTP_OK);
gopher_menu(&st);
break;
case S_IFREG:
log_combined(&st, HTTP_OK);
gopher_file(&st);
break;
default:
die(&st, ERR_ACCESS, "Refusing to serve out special files");
}
/* Clean exit */
return OK;
}
/*
* Convert gopher selector to an absolute path
*/
void selector_to_path(state *st)
{
DIR *dp;
struct dirent *dir;
struct stat file;
#ifdef HAVE_PASSWD
struct passwd *pwd;
char *path = EMPTY;
char *c;
#endif
char buf[BUFSIZE];
int i;
/* Handle selector rewriting */
for (i = 0; i < st->rewrite_count; i++) {
/* Match found? */
if (strstr(st->req_selector, st->rewrite[i].match) == st->req_selector) {
/* Replace match with a new string */
snprintf(buf, sizeof(buf), "%s%s",
st->rewrite[i].replace,
st->req_selector + strlen(st->rewrite[i].match));
if (st->debug) {
syslog(LOG_INFO, "rewriting selector \"%s\" -> \"%s\"",
st->req_selector, buf);
}
sstrlcpy(st->req_selector, buf);
}
}
#ifdef HAVE_PASSWD
/* Virtual userdir (~user -> /home/user/public_gopher)? */
if (*(st->user_dir) && sstrncmp(st->req_selector, "/~") == MATCH) {
/* Parse userdir login name & path */;
sstrlcpy(buf, st->req_selector + 2);
if ((c = strchr(buf, '/'))) {
*c = '\0';
path = c + 1;
}
/* Check user validity */
if ((pwd = getpwnam(buf)) == NULL)
die(st, ERR_NOTFOUND, "User not found");
if (pwd->pw_uid < PASSWD_MIN_UID)
die(st, ERR_NOTFOUND, "User found but UID too low");
/* Generate absolute path to users own gopher root */
snprintf(st->req_realpath, sizeof(st->req_realpath),
"%s/%s/%s", pwd->pw_dir, st->user_dir, path);
/* Check ~public_gopher access rights */
if (stat(st->req_realpath, &file) == ERROR)
die(st, ERR_NOTFOUND, NULL);
if ((file.st_mode & S_IROTH) == 0)
die(st, ERR_ACCESS, "~/public_gopher not world-readable");
if (file.st_uid != pwd->pw_uid)
die(st, ERR_ACCESS, "~/ and ~/public_gopher owned by different users");
/* Userdirs always come from the default vhost */
if (st->opt_vhost)
sstrlcpy(st->server_host, st->server_host_default);
return;
}
#endif
/* Virtual hosting */
if (st->opt_vhost) {
/* Try looking for the selector from the current vhost */
snprintf(st->req_realpath, sizeof(st->req_realpath), "%s/%s%s",
st->server_root, st->server_host, st->req_selector);
if (stat(st->req_realpath, &file) == OK) return;
/* Loop through all vhosts looking for the selector */
if ((dp = opendir(st->server_root)) == NULL) die(st, ERR_NOTFOUND, NULL);
while ((dir = readdir(dp))) {
/* Skip .hidden dirs and . & .. */
if (dir->d_name[0] == '.') continue;
/* Special case - skip lost+found (don't ask) */
if (sstrncmp(dir->d_name, "lost+found") == MATCH) continue;
/* Generate path to the found vhost */
snprintf(st->req_realpath, sizeof(st->req_realpath), "%s/%s%s",
st->server_root, dir->d_name, st->req_selector);
/* Did we find the selector under this vhost? */
if (stat(st->req_realpath, &file) == OK) {
/* Virtual host found - update state & return */
sstrlcpy(st->server_host, dir->d_name);
return;
}
}
closedir(dp);
}
/* Handle normal selectors */
snprintf(st->req_realpath, sizeof(st->req_realpath),
"%s%s", st->server_root, st->req_selector);
}
/*
* Handle gophermaps
*/
int gophermap(state *st, char *mapfile, int depth)
{
FILE *fp;
struct stat file;
char line[BUFSIZE];
#ifdef HAVE_POPEN
char command[BUFSIZE];
#endif
char *selector;
char *name;
char *host;
char *c;
char type;
int port;
int exe;
/* Prevent include loops */
if (depth > 4) return OK;
/* Try to figure out whether the map is executable */
if (stat(mapfile, &file) == OK) {
if ((file.st_mode & S_IXOTH)) {
#ifdef HAVE_POPEN
/* Quote the command in case path has spaces */
snprintf(command, sizeof(command), "'%s'", mapfile);
#endif
exe = TRUE;
}
else exe = FALSE;
}
/* This must be a shell include */
else {
#ifdef HAVE_POPEN
/* Let's assume the shell command runs as is without quoting */
sstrlcpy(command, mapfile);
#endif
exe = TRUE;
}
/* Debug output */
if (st->debug) {
if (exe) syslog(LOG_INFO, "parsing executable gophermap \"%s\"", mapfile);
else syslog(LOG_INFO, "parsing static gophermap \"%s\"", mapfile);
}
/* Try to execute or open the mapfile */
#ifdef HAVE_POPEN
if (exe) {
setenv_cgi(st, mapfile);
if ((fp = popen(command, "r")) == NULL) return OK;
}
else
#endif
if ((fp = fopen(mapfile, "r")) == NULL) return OK;
/* Read lines one by one */
while (fgets(line, sizeof(line) - 1, fp)) {
/* Parse type & name */
chomp(line);
type = line[0];
name = line + 1;
/* Ignore #comments */
if (type == '#') continue;
/* Stop handling gophermap? */
if (type == '*') return OK;
if (type == '.') return QUIT;
/* Print a list of users with public_gopher */
if (type == '~') {
#ifdef HAVE_PASSWD
userlist(st);
#endif
continue;
}
/* Print a list of available virtual hosts */
if (type == '%') {
if (st->opt_vhost) vhostlist(st);
continue;
}
/* Hide files in menus */
if (type == '-') {
if (st->hidden_count < MAX_HIDDEN)
sstrlcpy(st->hidden[st->hidden_count++], name);
continue;
}
/* Override filetype mappings */
if (type == ':') {
add_ftype_mapping(st, name);
continue;
}
/* Include gophermap or shell exec */
if (type == '=') {
gophermap(st, name, depth + 1);
continue;
}
/* Title resource */
if (type == TYPE_TITLE) {
info(st, name, TYPE_TITLE);
continue;
}
/* Print out non-resources as info text */
if (!strchr(line, '\t')) {
info(st, line, TYPE_INFO);
continue;
}
/* Parse selector */
selector = EMPTY;
if ((c = strchr(name, '\t'))) {
*c = '\0';
selector = c + 1;
}
if (!*selector) selector = name;
/* Parse host */
host = st->server_host;
if ((c = strchr(selector, '\t'))) {
*c = '\0';
host = c + 1;
}
/* Parse port */
port = st->server_port;
if ((c = strchr(host, '\t'))) {
*c = '\0';
port = atoi(c + 1);
}
/* Handle remote, absolute and hURL gopher resources */
if (sstrncmp(selector, "URL:") == MATCH ||
selector[0] == '/' ||
host != st->server_host) {
printf("%c%s\t%s\t%s\t%i" CRLF, type, name,
selector, host, port);
}
/* Handle relative resources */
else {
printf("%c%s\t%s%s\t%s\t%i" CRLF, type, name,
st->req_selector, selector, host, port);
/* Automatically hide manually defined selectors */
#ifdef ENABLE_AUTOHIDING
if (st->hidden_count < MAX_HIDDEN)
sstrlcpy(st->hidden[st->hidden_count++], selector);
#endif
}
}
/* Clean up & return */
#ifdef HAVE_POPEN
if (exe) pclose(fp);
else
#endif
fclose(fp);
return QUIT;
}
/*
* Return gopher filetype for a file
*/
char gopher_filetype(state *st, char *file, char magic)
{
FILE *fp;
char buf[BUFSIZE];
char *c;
int i;
/* If it ends with an slash it's a menu */
if (!*file) return st->default_filetype;
if (strlast(file) == '/') return TYPE_MENU;
/* Get file suffix */
if ((c = strrchr(file, '.'))) {
c++;
/* Loop through the filetype array looking for a match*/
for (i = 0; i < st->filetype_count; i++)
if (strcasecmp(st->filetype[i].suffix, c) == MATCH)
return st->filetype[i].type;
}
/* Are we allowed to look inside files? */
if (!magic) return st->default_filetype;
/* Read data from the file */
if ((fp = fopen(file , "r")) == NULL) return st->default_filetype;
i = fread(buf, 1, sizeof(buf) - 1, fp);
buf[i] = '\0';
fclose(fp);
/* GIF images */
if (sstrncmp(buf, "GIF89a") == MATCH ||
sstrncmp(buf, "GIF87a") == MATCH) return TYPE_GIF;
/* JPEG images */
if (sstrncmp(buf, "\377\330\377\340") == MATCH) return TYPE_IMAGE;
/* PNG images */
if (sstrncmp(buf, "\211PNG") == MATCH) return TYPE_IMAGE;
/* mbox */
if (strstr(buf, "\nFrom: ") &&
strstr(buf, "\nSubject: ")) return TYPE_MIME;
/* MIME */
if (strstr(buf, "\nContent-Type: ")) return TYPE_MIME;
/* HTML files */
if (buf[0] == '<' &&
(strstr(buf, "<html") ||
strstr(buf, "<HTML"))) return TYPE_HTML;
/* PDF and PostScript */
if (sstrncmp(buf, "%PDF-") == MATCH ||
sstrncmp(buf, "%!") == MATCH) return TYPE_DOC;
/* compress and gzip */
if (sstrncmp(buf, "\037\235\220") == MATCH ||
sstrncmp(buf, "\037\213\010") == MATCH) return TYPE_GZIP;
/* Unknown content - binary or text? */
if (memchr(buf, '\0', i)) return TYPE_BINARY;
return st->default_filetype;
}
