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whois: make it actually work

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It was doing way too simplistic work of just querying the server,
no redirects, no query massaging. This required user to know a lot about whois,
and enter at least three queries for each host to get meaningful information.

function                                             old     new   delta
whois_main                                           209     646    +437

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2016-07-06 15:45:41 +02:00
parent f4f8fe841c
commit 1035c92e2d
1 changed files with 124 additions and 13 deletions
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137
networking/whois.c
View File

@ -28,36 +28,147 @@
#include "libbb.h"
static void pipe_out(int fd)
static char *query(const char *host, int port, const char *domain)
{
int fd;
FILE *fp;
char buf[1024];
bool success;
char *redir = NULL;
const char *pfx = "";
char linebuf[1024];
char *buf = NULL;
unsigned bufpos = 0;
again:
printf("[Querying %s:%d '%s%s']\n", host, port, pfx, domain);
fd = create_and_connect_stream_or_die(host, port);
success = 0;
fdprintf(fd, "%s%s\r\n", pfx, domain);
fp = xfdopen_for_read(fd);
while (fgets(buf, sizeof(buf), fp)) {
char *p = strpbrk(buf, "\r\n");
if (p)
*p = '\0';
puts(buf);
while (fgets(linebuf, sizeof(linebuf), fp)) {
unsigned len = strcspn(linebuf, "\r\n");
linebuf[len++] = '\n';
buf = xrealloc(buf, bufpos + len + 1);
memcpy(buf + bufpos, linebuf, len);
bufpos += len;
if (!redir || !success) {
trim(linebuf);
str_tolower(linebuf);
if (!success) {
success = is_prefixed_with(linebuf, "domain:")
|| is_prefixed_with(linebuf, "domain name:");
}
else if (!redir) {
char *p = is_prefixed_with(linebuf, "whois server:");
if (!p)
p = is_prefixed_with(linebuf, "whois:");
if (p)
redir = xstrdup(skip_whitespace(p));
}
}
}
fclose(fp); /* closes fd too */
if (!success && !pfx[0]) {
/*
* Looking at jwhois.conf, some whois servers use
* "domain = DOMAIN", "DOMAIN ID <DOMAIN>"
* and "domain=DOMAIN_WITHOUT_LAST_COMPONENT"
* formats, but those are rare.
* (There are a few even more contrived ones.)
* We are trying only "domain DOMAIN", the typical one.
*/
pfx = "domain ";
bufpos = 0;
goto again;
}
fclose(fp); /* closes fd too */
/* Success */
if (redir && strcmp(redir, host) == 0) {
/* Redirect to self does not count */
free(redir);
redir = NULL;
}
if (!redir) {
/* Output saved text */
printf("[%s]\n", host);
buf[bufpos] = '\0';
fputs(buf, stdout);
}
free(buf);
return redir;
}
static void recursive_query(const char *host, int port, const char *domain)
{
char *free_me = NULL;
char *redir;
again:
redir = query(host, port, domain);
free(free_me);
if (redir) {
printf("[Redirected to %s]\n", redir);
host = free_me = redir;
port = 43;
goto again;
}
}
/* One of "big" whois implementations has these options:
*
* $ whois --help
* jwhois version 4.0, Copyright (C) 1999-2007 Free Software Foundation, Inc.
* -v, --verbose verbose debug output
* -c FILE, --config=FILE use FILE as configuration file
* -h HOST, --host=HOST explicitly query HOST
* -n, --no-redirect disable content redirection
* -s, --no-whoisservers disable whois-servers.net service support
* -a, --raw disable reformatting of the query
* -i, --display-redirections display all redirects instead of hiding them
* -p PORT, --port=PORT use port number PORT (in conjunction with HOST)
* -r, --rwhois force an rwhois query to be made
* --rwhois-display=DISPLAY sets the display option in rwhois queries
* --rwhois-limit=LIMIT sets the maximum number of matches to return
*
* Example of its output:
* $ whois cnn.com
* [Querying whois.verisign-grs.com]
* [Redirected to whois.corporatedomains.com]
* [Querying whois.corporatedomains.com]
* [whois.corporatedomains.com]
* ...text of the reply...
*
* With -i, reply from each server is printed, after all redirects are done:
* [Querying whois.verisign-grs.com]
* [Redirected to whois.corporatedomains.com]
* [Querying whois.corporatedomains.com]
* [whois.verisign-grs.com]
* ...text of the reply...
* [whois.corporatedomains.com]
* ...text of the reply...
*
* With -a, no "DOMAIN" -> "domain DOMAIN" transformation is attempted.
* With -n, the first reply is shown, redirects are not followed:
* [Querying whois.verisign-grs.com]
* [whois.verisign-grs.com]
* ...text of the reply...
*/
int whois_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int whois_main(int argc UNUSED_PARAM, char **argv)
{
int port = 43;
const char *host = "whois-servers.net";
const char *host = "whois.iana.org";
opt_complementary = "-1:p+";
getopt32(argv, "h:p:", &host, &port);
argv += optind;
do {
int fd = create_and_connect_stream_or_die(host, port);
fdprintf(fd, "%s\r\n", *argv);
pipe_out(fd);
recursive_query(host, port, *argv);
}
while (*++argv);