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#include "qpage.h"
/*
** global variables
*/
#ifndef lint
static char sccsid[] = "@(#)ident.c 1.11 03/12/98 tomiii@qpage.org";
#endif
/*
** trim()
**
** This function trims leading and trailing whitespace from a string.
** The string is modified in place. Since the result will be less than
** or equal to the size of the original string, this should not be a
** problem.
**
** Input:
** str - the string to trim
**
** Returns:
** nothing
*/
void
trim(char *str)
{
char *start;
char *end;
for (start=str; *start && isspace(*start); start++)
continue;
end = start + strlen(start) - 1;
while (end >= start && isspace(*end))
*end-- = '\0';
if (str != start)
(void)strcpy(str, start);
}
/*
** ident()
**
** This function queries the remote host's ident server to find the
** userid at the other end of the connection.
**
** Input:
** peer - the open socket for this connection
**
** Returns:
** the userid returned from the ident query, or NULL on error
**
** Note:
** The string returned by this function is obtained via
** malloc(). It is therefore the caller's responsibility
** to free this memory when it is no longer needed.
*/
char *
ident(int peer)
{
struct sockaddr_in addr;
struct servent *svc;
char buff[1024];
char type[1024];
char os[1024];
char user[1024];
char *ptr;
int sock;
int theirport;
int ourport;
int left;
int len;
int i;
/*
** get our port number
*/
len = sizeof(addr);
if (getsockname(peer, (struct sockaddr *)&addr, &len) < 0) {
if (Debug)
qpage_log(LOG_DEBUG, "ident.getsockname() failed: %s",
strerror(errno));
return(NULL);
}
ourport = ntohs(addr.sin_port);
/*
** get their port number
*/
len = sizeof(addr);
if (getpeername(peer, (struct sockaddr *)&addr, &len) < 0) {
if (Debug)
qpage_log(LOG_DEBUG, "ident.getpeername() failed: %s",
strerror(errno));
return(NULL);
}
theirport = ntohs(addr.sin_port);
if ((svc = getservbyname("ident", "tcp")) != NULL)
addr.sin_port = svc->s_port;
else
addr.sin_port = htons(113);
if ((sock = socket(PF_INET, SOCK_STREAM, 0)) < 0) {
if (Debug)
qpage_log(LOG_DEBUG, "ident.socket() failed: %s",
strerror(errno));
return(NULL);
}
/*
** set the alarm so we don't hang
*/
(void)alarm(IdentTimeout);
/*
** set the alarm so we don't hang
*/
if (setjmp(TimeoutEnv) > 0) {
(void)close(sock);
return(NULL);
}
if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
if (Debug) {
if (errno == ECONNREFUSED) {
qpage_log(LOG_DEBUG,
"RFC-1413 query refused by remote");
}
else
qpage_log(LOG_DEBUG,
"ident.connect() failed: %s",
strerror(errno));
}
(void)close(sock);
(void)alarm(0);
return(NULL);
}
(void)sprintf(buff, "%u, %u\r\n", theirport, ourport);
if (write(sock, buff, strlen(buff)) < 0) {
if (Debug)
qpage_log(LOG_DEBUG, "ident.write() failed: %s",
strerror(errno));
(void)close(sock);
(void)alarm(0);
return(NULL);
}
ptr = buff;
left = sizeof(buff) - 1;
while ((i = read(sock, ptr, left)) > 0) {
ptr += i;
left -= i;
}
(void)close(sock);
/*
** we're safe, cancel the alarm and restore the signal handler
*/
(void)alarm(0);
if ((i < 0) || (ptr == buff)) {
if (Debug)
qpage_log(LOG_DEBUG, "no valid ident response");
return(NULL);
}
*ptr-- = '\0';
if (*ptr == '\n')
*ptr-- = '\0';
if (*ptr == '\r')
*ptr-- = '\0';
i = sscanf(buff, "%*[^:]:%[^:]:%[^:]:%[^\r\n]", type, os, user);
if (i != 3) {
if (Debug)
qpage_log(LOG_DEBUG, "no valid ident response");
return(NULL);
}
trim(type);
trim(os);
trim(user);
if (Debug)
qpage_log(LOG_DEBUG, "ident: type=<%s>, os=<%s>, user=<%s>",
type, os, user);
if (!strcasecmp(type, "userid") && strcasecmp(os, "other")) {
ptr = strdup(user);
return(ptr);
}
return(NULL);
}
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