putty/sessprep.c

85 строки
2.6 KiB
C

/*
* sessprep.c: centralise some preprocessing done on Conf objects
* before launching them.
*/
#include "putty.h"
void prepare_session(Conf *conf)
{
char *hostbuf = dupstr(conf_get_str(conf, CONF_host));
char *host = hostbuf;
char *p, *q;
/*
* Trim leading whitespace from the hostname.
*/
host += strspn(host, " \t");
/*
* See if host is of the form user@host, and separate out the
* username if so.
*/
if (host[0] != '\0') {
/*
* Use strrchr, in case the _username_ in turn is of the form
* user@host, which has been known.
*/
char *atsign = strrchr(host, '@');
if (atsign) {
*atsign = '\0';
conf_set_str(conf, CONF_username, host);
host = atsign + 1;
}
}
/*
* Trim a colon suffix off the hostname if it's there, and discard
* the text after it.
*
* The exact reason why we _ignore_ this text, rather than
* treating it as a port number, is unfortunately lost in the
* mists of history: the commit which originally introduced this
* change on 2001-05-06 was clear on _what_ it was doing but
* didn't bother to explain _why_. But I [SGT, 2017-12-03] suspect
* it has to do with priority order: what should a saved session
* do if its CONF_host contains 'server.example.com:123' and its
* CONF_port contains 456? If CONF_port contained the _default_
* port number then it might be a good guess that the colon suffix
* on the host name was intended to override that, but you don't
* really want to get into making heuristic judgments on that
* basis.
*
* (Then again, you could just as easily make the same argument
* about whether a 'user@' prefix on the host name should override
* CONF_username, which this code _does_ do. I don't have a good
* answer, sadly. Both these pieces of behaviour have been around
* for years and it would probably cause subtle breakage in all
* sorts of long-forgotten scripting to go changing things around
* now.)
*
* In order to protect unbracketed IPv6 address literals against
* this treatment, we do not make this change at all if there's
* _more_ than one (un-IPv6-bracketed) colon.
*/
p = host_strchr(host, ':');
if (p && p == host_strrchr(host, ':')) {
*p = '\0';
}
/*
* Remove any remaining whitespace.
*/
p = hostbuf;
q = host;
while (*q) {
if (*q != ' ' && *q != '\t')
*p++ = *q;
q++;
}
*p = '\0';
conf_set_str(conf, CONF_host, hostbuf);
sfree(hostbuf);
}