NetBSD/gnu/dist/postfix/global/resolve_clnt.c

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/*++
/* NAME
/* resolve_clnt 3
/* SUMMARY
/* address resolve service client (internal forms)
/* SYNOPSIS
/* #include <resolve_clnt.h>
/*
/* typedef struct {
/* .in +4
/* VSTRING *transport;
/* VSTRING *nexthop
/* VSTRING *recipient;
/* int flags;
/* .in -4
/* } RESOLVE_REPLY;
/*
/* void resolve_clnt_init(reply)
/* RESOLVE_REPLY *reply;
/*
/* void resolve_clnt_query(address, reply)
/* const char *address
/* RESOLVE_REPLY *reply;
/*
/* void resolve_clnt_free(reply)
/* RESOLVE_REPLY *reply;
/* DESCRIPTION
/* This module implements a mail address resolver client.
/*
/* resolve_clnt_init() initializes a reply data structure for use
/* by resolve_clnt_query(). The structure is destroyed by passing
/* it to resolve_clnt_free().
/*
/* resolve_clnt_query() sends an internal-form recipient address
/* (user@domain) to the resolver daemon and returns the resulting
/* transport name, next_hop host name, and internal-form recipient
/* address. In case of communication failure the program keeps trying
/* until the mail system goes down.
/*
/* In the resolver reply, the flags member is the bit-wise OR of
/* zero or more of the following:
/* .IP RESOLVE_FLAG_FINAL
/* The recipient address resolves to a mail transport that performs
/* final delivery. The destination is local or corresponds to a hosted
/* domain that is handled by the local machine. This flag is currently
/* not used.
/* .IP RESOLVE_FLAG_ROUTED
/* After address resolution the recipient localpart contains further
/* routing information, so the resolved next-hop destination is not
/* the final destination.
/* DIAGNOSTICS
/* Warnings: communication failure. Fatal error: mail system is down.
/* SEE ALSO
/* mail_proto(3h) low-level mail component glue.
/* LICENSE
/* .ad
/* .fi
/* The Secure Mailer license must be distributed with this software.
/* AUTHOR(S)
/* Wietse Venema
/* IBM T.J. Watson Research
/* P.O. Box 704
/* Yorktown Heights, NY 10598, USA
/*--*/
/* System library. */
#include <sys_defs.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
/* Utility library. */
#include <msg.h>
#include <vstream.h>
#include <vstring.h>
#include <vstring_vstream.h>
#include <events.h>
#include <iostuff.h>
/* Global library. */
#include "mail_proto.h"
#include "mail_params.h"
#include "clnt_stream.h"
#include "resolve_clnt.h"
/* Application-specific. */
/*
* XXX this is shared with the rewrite client to save a file descriptor.
*/
extern CLNT_STREAM *rewrite_clnt_stream;
static VSTRING *last_addr;
static RESOLVE_REPLY last_reply;
/* resolve_clnt_init - initialize reply */
void resolve_clnt_init(RESOLVE_REPLY *reply)
{
reply->transport = vstring_alloc(100);
reply->nexthop = vstring_alloc(100);
reply->recipient = vstring_alloc(100);
reply->flags = 0;
}
/* resolve_clnt_query - resolve address to (transport, next hop, recipient) */
void resolve_clnt_query(const char *addr, RESOLVE_REPLY *reply)
{
char *myname = "resolve_clnt_query";
VSTREAM *stream;
/*
* One-entry cache.
*/
if (last_addr == 0) {
last_addr = vstring_alloc(100);
resolve_clnt_init(&last_reply);
}
/*
* Sanity check. The result must not clobber the input because we may
* have to retransmit the request.
*/
#define STR vstring_str
if (addr == STR(reply->recipient))
msg_panic("%s: result clobbers input", myname);
/*
* Peek at the cache.
*/
if (strcmp(addr, STR(last_addr)) == 0) {
vstring_strcpy(reply->transport, STR(last_reply.transport));
vstring_strcpy(reply->nexthop, STR(last_reply.nexthop));
vstring_strcpy(reply->recipient, STR(last_reply.recipient));
reply->flags = last_reply.flags;
if (msg_verbose)
msg_info("%s: cached: `%s' -> t=`%s' h=`%s' r=`%s'",
myname, addr, STR(reply->transport),
STR(reply->nexthop), STR(reply->recipient));
return;
}
/*
* Keep trying until we get a complete response. The resolve service is
* CPU bound; making the client asynchronous would just complicate the
* code.
*/
if (rewrite_clnt_stream == 0)
rewrite_clnt_stream = clnt_stream_create(MAIL_CLASS_PRIVATE,
MAIL_SERVICE_REWRITE, var_ipc_idle_limit);
for (;;) {
stream = clnt_stream_access(rewrite_clnt_stream);
if (mail_print(stream, "%s %s", RESOLVE_ADDR, addr)
|| vstream_fflush(stream)) {
if (msg_verbose || (errno != EPIPE && errno != ENOENT))
msg_warn("%s: bad write: %m", myname);
} else if (mail_scan(stream, "%s %s %s %d",
reply->transport, reply->nexthop,
reply->recipient, &reply->flags) != 4) {
if (msg_verbose || (errno != EPIPE && errno != ENOENT))
msg_warn("%s: bad read: %m", myname);
} else {
if (msg_verbose)
msg_info("%s: `%s' -> t=`%s' h=`%s' r=`%s'",
myname, addr, STR(reply->transport),
STR(reply->nexthop), STR(reply->recipient));
if (STR(reply->transport)[0] == 0)
msg_warn("%s: null transport result for: <%s>", myname, addr);
else if (STR(reply->recipient)[0] == 0)
msg_warn("%s: null recipient result for: <%s>", myname, addr);
else
break;
}
sleep(10); /* XXX make configurable */
clnt_stream_recover(rewrite_clnt_stream);
}
/*
* Update the cache.
*/
vstring_strcpy(last_addr, addr);
vstring_strcpy(last_reply.transport, STR(reply->transport));
vstring_strcpy(last_reply.nexthop, STR(reply->nexthop));
vstring_strcpy(last_reply.recipient, STR(reply->recipient));
last_reply.flags = reply->flags;
}
/* resolve_clnt_free - destroy reply */
void resolve_clnt_free(RESOLVE_REPLY *reply)
{
reply->transport = vstring_free(reply->transport);
reply->nexthop = vstring_free(reply->nexthop);
reply->recipient = vstring_free(reply->recipient);
}
#ifdef TEST
#include <stdlib.h>
#include <msg_vstream.h>
#include <vstring_vstream.h>
#include <mail_conf.h>
static NORETURN usage(char *myname)
{
msg_fatal("usage: %s [-v] [address...]", myname);
}
static void resolve(char *addr, RESOLVE_REPLY *reply)
{
resolve_clnt_query(addr, reply);
vstream_printf("%-10s %s\n", "address", addr);
vstream_printf("%-10s %s\n", "transport", STR(reply->transport));
vstream_printf("%-10s %s\n", "nexthop", *STR(reply->nexthop) ?
STR(reply->nexthop) : "[none]");
vstream_printf("%-10s %s\n", "recipient", STR(reply->recipient));
vstream_fflush(VSTREAM_OUT);
}
main(int argc, char **argv)
{
RESOLVE_REPLY reply;
int ch;
msg_vstream_init(argv[0], VSTREAM_ERR);
mail_conf_read();
msg_info("using config files in %s", var_config_dir);
if (chdir(var_queue_dir) < 0)
msg_fatal("chdir %s: %m", var_queue_dir);
while ((ch = GETOPT(argc, argv, "v")) > 0) {
switch (ch) {
case 'v':
msg_verbose++;
break;
default:
usage(argv[0]);
}
}
resolve_clnt_init(&reply);
if (argc > optind) {
while (argv[optind]) {
resolve(argv[optind], &reply);
optind++;
}
} else {
VSTRING *buffer = vstring_alloc(1);
while (vstring_fgets_nonl(buffer, VSTREAM_IN)) {
resolve(STR(buffer), &reply);
}
}
}
#endif