/* Find name of host by calling nameserver
** ---------------------------------------
**
** Language: ANSI C
*/
#include <stdio.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <libc.h>
#include "../../Implementation/HTParse.h"
#define HOST_OFFSET 25 /* Offset to host number in status line */
#define END_OF_DATE 10 /* Number of chars in date */
#define SKIP 4 /* Boring part of request "GET " */
/* int WWW_TraceFlag = 0; */ /* Control diagnostic output */
int more_trace = 0; /* Higher level */
FILE * host_input = NULL;
FILE * host_output = NULL;
FILE * host_append = NULL;
char * host_append_filename = NULL;
/* IP address info
*/
typedef struct _host_details {
struct _host_details * next;
unsigned long addr;
char * name; /* If zero, name is unknown */
int count;
int status;
} host_details;
#define HASH_SIZE 1001
static host_details *hosts[HASH_SIZE];
/* Initialize host names
*/
void initialize_hosts(void)
{
int i;
for (i=0; i<HASH_SIZE; i++) hosts[i] = NULL;
}
/* print error message for hostname lookup
*/
void pherror(int e)
{
switch (e) {
case HOST_NOT_FOUND: fprintf(stderr,
" HOST NOT FOUND: no such host is known\n");
break;
case TRY_AGAIN: fprintf(stderr, " TRY AGAIN.\n");
if (more_trace) fprintf(stderr,
" This is usually a temporary error and means that\n"
" the local server did not receive a response from an\n"
" authoritative server. A retry at some later time may \n"
" succeed.\n");
break;
case NO_RECOVERY : fprintf(stderr,
" NO_RECOVERY.\n");
if (more_trace) fprintf(stderr,
" Some unexpected server failure was encountered.\n"
" This is a non-recoverable error.\n");
break;
case NO_DATA : fprintf(stderr, "NO DATA.\n");
if (more_trace) fprintf(stderr,
" The requested name is valid but does not have an IP address;\n"
" this is not a temporary error. This means that the name is known \n"
" to the name server but there is no address associated with\n"
" this name. Another type of request to\n"
" the name server using this domain name\n"
" will result in an answer; for example,\n"
" a mail-forwarder may be registered for\n"
" this domain.\n");
break;
default: fprintf(stderr, "Unknown error from gethostbyaddr: %d\n", h_errno);
}
}
/* Record a host's cannonical name
** -------------------------------
**
** Returns address of allocated copy of name
*/
char * record_host_name(unsigned long addr, char * name, int status, int trace)
{
host_details * p = (host_details *) (hosts + (addr % HASH_SIZE));
for (;p->next;p=p->next) {
if (p->next->addr == addr) return; /* got it */
}
/* Not found: p->next is NULL */
p->next = (host_details *) malloc(sizeof(*p));
if (!p->next) {
fprintf(stderr, "Out of memory!\n\n");
exit(2);
}
p->next->next = NULL;
p->next->addr = addr;
p->next->status = status;
if (name) {
p->next->name = malloc(strlen(name)+1);
if (!p->next->name) {
fprintf(stderr, "Out of memory!\n\n");
exit (3);
}
strcpy(p->next->name, name);
} else p->next->name = NULL;
p->next->count = 1;
if (trace) fprintf(stderr, "New host %u.%u.%u.%u is %s\n",
((unsigned char *)(&addr))[0],
((unsigned char *)(&addr))[1],
((unsigned char *)(&addr))[2],
((unsigned char *)(&addr))[3],
name ? name : "UNKNOWN");
if (host_append) {
fprintf(host_append, "%03d.%03d.%03d.%03d %2d %4d %s \n",
((unsigned char *)(&addr))[0],
((unsigned char *)(&addr))[1],
((unsigned char *)(&addr))[2],
((unsigned char *)(&addr))[3],
status,
0,
name ? name : "?"
);
}
return p->next->name;
}
/* Load a host file
** ================
*/
void load_hosts(const char * fn)
{
FILE * fp = fopen(fn, "r");
char line[512];
char addr_string[80];
char name[256];
char * result;
unsigned long addr, last_addr;
char date[END_OF_DATE+1];
char host[255];
int count, status;
int lines = 0;
if (!fp) {
fprintf(stderr, "Can't open hosts input file %s\n", fn);
exit(6);
}
for (;;) {
result = fgets(line, sizeof(line), fp);
if (!result) break;
if (line[0] == '#') continue; /* Ignore comment lines */
sscanf(line, "%s%u%u%s", addr_string, &status, &count, name);
record_host_name(inet_addr(addr_string), name, status, more_trace);
lines++;
}
fclose(fp);
if (TRACE) fprintf(stderr, "Total of %d hosts in %s\n", lines, fn);
}
/* Find a host name
** ----------------
*/
char * host_name(unsigned long addr)
{
struct hostent *phost;
host_details * p = (host_details *) (hosts + (addr % HASH_SIZE));
for (;p->next;p=p->next) {
if (p->next->addr == addr) {
p->next->count++;
return p->next->name; /* got it */
}
}
/* Not found: p->next is NULL */
phost = gethostbyaddr((char*)&addr, sizeof(addr), AF_INET);
if (phost) return record_host_name(addr, phost->h_name, 0, WWW_TraceFlag);
record_host_name(addr, NULL, h_errno, WWW_TraceFlag); /* Don't try again */
if (TRACE) {
fprintf(stderr, "*** Can't look up %u.%u.%u.%u: ",
((unsigned char *)(&addr))[0],
((unsigned char *)(&addr))[1],
((unsigned char *)(&addr))[2],
((unsigned char *)(&addr))[3]);
pherror(h_errno);
}
return NULL;
}
/* Analyse the file
** ================
*/
void analyse(void)
{
char line[512];
char * result;
unsigned long addr, last_addr;
char date[END_OF_DATE+1];
char host[255];
int requests = 0;
date[0]=0; /* invalidate */
last_addr = 0;
for (;;) {
char * end_of_host;
result = fgets(line, sizeof(line), stdin);
if (!result) return;
if (line[0] == '*') continue; /* Ignore error lines */
if (line[0] <= ' ') continue; /* Ignore starting with white space */
end_of_host = strchr(&line[HOST_OFFSET], ' ');
line[HOST_OFFSET-1] =0; /* Chop line up */
if (!end_of_host)
end_of_host = &line[HOST_OFFSET]+strlen(&line[HOST_OFFSET]);
else
*end_of_host = 0;
line[END_OF_DATE] = 0;
addr = inet_addr(&line[HOST_OFFSET]);
/* get new host name */
if (addr!=last_addr) {
/* phost = gethostbyaddr((char*)&addr, sizeof(addr), AF_INET);
if (phost) strcpy(host, phost->h_name);
else strcpy(host, &line[HOST_OFFSET]);
*/
char * name = host_name(addr);
strcpy(host, name? name : &line[HOST_OFFSET]);
last_addr = addr;
}
/* Print */
#ifdef SUMMARY
if (strcmp(date, line)!=0) {
if (*date) printf(" %d requests on %s\n\n", requests, date);
requests = 0;
strcpy(date, line);
printf("%s %s %-25s %s",
date, &line[END_OF_DATE+1], host, end_of_host+1+SKIP);
} else {
printf(" %s %-25s %s",
&line[END_OF_DATE+1], host, end_of_host+1+SKIP);
}
#else
if (strlen(end_of_host+1) > SKIP) {
HTSimplify(end_of_host+1+SKIP);
printf("%s %s %-25s %s",
line, &line[END_OF_DATE+1], host, end_of_host+1+SKIP);
} else {
printf("%s %s %-25s %s",
line, &line[END_OF_DATE+1], host, "** BAD_COMMAND\n");
}
#endif
requests++;
if (TRACE && (requests %1000)==0) fprintf(stderr,
"Processed %d requests ....\n", requests);
}
}
/* Main program
** ============
*/
main(int argc, char*argv[])
{
struct hostent *phost;
unsigned long addr;
/*
struct sockaddr_in sa;
*/
int a;
initialize_hosts();
for(a=1; a<argc; a++){
if (!strcmp(argv[a], "-v")) {
WWW_TraceFlag = 1; /* Verbose */
} else if (!strcmp(argv[a], "-vv")) {
WWW_TraceFlag = 1; /* Verbose */
more_trace = 1; /* very verbose */
} else if (!strcmp(argv[a], "-hi") && ++a<argc) {
load_hosts(argv[a]);
} else if (!strcmp(argv[a], "-ho") && ++a<argc) {
host_output = fopen(argv[a], "w");
if (!host_output) {
fprintf(stderr, "can't open %s for host output.\n", argv[a]);
exit (4);
}
} else if (!strcmp(argv[a], "-ha") && ++a<argc) {
host_append_filename = argv[a];
/* -a addr just looks up one address */
} else if (!strcmp(argv[a], "-a") && ++a<argc) {
unsigned long addr = inet_addr(argv[a]);
printf("%s\n", host_name(addr));
exit (0);
}
} /* end scan argument list */
if (host_append_filename) {
load_hosts(host_append_filename);
host_append = fopen(host_append_filename, "a");
if (!host_append) {
fprintf(stderr, "can't open %s for host append.\n", argv[a]);
exit (4);
}
}
analyse();
if (host_append) fclose(host_append);
/* Output host list
*/
if (host_output) {
int i;
host_details *p;
for(i=0; i<HASH_SIZE; i++) {
for(p=hosts[i]; p; p=p->next) {
fprintf(host_output, "%03d.%03d.%03d.%03d %d %d %s\n",
((unsigned char *)(&p->addr))[0],
((unsigned char *)(&p->addr))[1],
((unsigned char *)(&p->addr))[2],
((unsigned char *)(&p->addr))[3],
p->status,
p->count,
p->name ? p->name : "?"
);
}
}
fclose(host_output);
}
exit(0);
}
/*
HOST_NOT_FOUND No such host is known.
TRY_AGAIN This is usually a temporary error and
means that the local server did not
receive a response from an authorita-
tive server. A retry at some later
time may succeed.
NO_RECOVERY Some unexpected server failure was
encountered. This is a non-recoverable
error.
NO_DATA The requested name is valid but does
not have an IP address; this is not a
temporary error. This means that the
name is known to the name server but
there is no address associated with
this name. Another type of request to
the name server using this domain name
will result in an answer; for example,
a mail-forwarder may be registered for
this domain.
*/