| Current File : //root/postfix-3.2.0/src/global/resolve_clnt.c |
/*++
/* 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_from(sender, address, reply)
/* const char *sender;
/* const char *address;
/* RESOLVE_REPLY *reply;
/*
/* void resolve_clnt_verify_from(sender, address, reply)
/* const char *sender;
/* 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_from() 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. The internal-form sender
/* information is used for sender-dependent relayhost lookup.
/* Specify RESOLVE_NULL_FROM when the sender is unavailable.
/*
/* resolve_clnt_verify_from() implements an alternative version that can
/* be used for address verification.
/*
/* 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.
/* .IP RESOLVE_FLAG_ERROR
/* The address resolved to something that has invalid syntax.
/* .IP RESOLVE_FLAG_FAIL
/* The request could not be completed.
/* .PP
/* In addition, the address domain class is returned by setting
/* one of the following flags (this is preliminary code awaiting
/* more permanent implementation of address domain class handling):
/* .IP RESOLVE_CLASS_LOCAL
/* The address domain matches $mydestination, $inet_interfaces
/* or $proxy_interfaces.
/* .IP RESOLVE_CLASS_ALIAS
/* The address domain matches $virtual_alias_domains (virtual
/* alias domains, where each address is redirected to a real
/* local or remote address).
/* .IP RESOLVE_CLASS_VIRTUAL
/* The address domain matches $virtual_mailbox_domains (true
/* virtual domains where each address can have its own mailbox).
/* .IP RESOLVE_CLASS_RELAY
/* The address domain matches $relay_domains, i.e. this is an
/* authorized mail relay destination.
/* .IP RESOLVE_CLASS_DEFAULT
/* The address matches none of the above. Access to this domain
/* should be limited to authorized senders only.
/* .PP
/* For convenience, the constant RESOLVE_CLASS_FINAL includes all
/* cases where the local machine is 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 time_t last_expire;
static VSTRING *last_class;
static VSTRING *last_sender;
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 - resolve address to (transport, next hop, recipient) */
void resolve_clnt(const char *class, const char *sender,
const char *addr, RESOLVE_REPLY *reply)
{
const char *myname = "resolve_clnt";
VSTREAM *stream;
int server_flags;
int count = 0;
/*
* One-entry cache.
*/
if (last_addr == 0) {
last_class = vstring_alloc(10);
last_sender = vstring_alloc(10);
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.
*/
#define IFSET(flag, text) ((reply->flags & (flag)) ? (text) : "")
if (time((time_t *) 0) < last_expire
&& *addr && strcmp(addr, STR(last_addr)) == 0
&& strcmp(class, STR(last_class)) == 0
&& strcmp(sender, STR(last_sender)) == 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' -> `%s' -> transp=`%s' host=`%s' rcpt=`%s' flags=%s%s%s%s class=%s%s%s%s%s",
myname, sender, addr, STR(reply->transport),
STR(reply->nexthop), STR(reply->recipient),
IFSET(RESOLVE_FLAG_FINAL, "final"),
IFSET(RESOLVE_FLAG_ROUTED, "routed"),
IFSET(RESOLVE_FLAG_ERROR, "error"),
IFSET(RESOLVE_FLAG_FAIL, "fail"),
IFSET(RESOLVE_CLASS_LOCAL, "local"),
IFSET(RESOLVE_CLASS_ALIAS, "alias"),
IFSET(RESOLVE_CLASS_VIRTUAL, "virtual"),
IFSET(RESOLVE_CLASS_RELAY, "relay"),
IFSET(RESOLVE_CLASS_DEFAULT, "default"));
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,
var_rewrite_service,
var_ipc_idle_limit,
var_ipc_ttl_limit);
for (;;) {
stream = clnt_stream_access(rewrite_clnt_stream);
errno = 0;
count += 1;
if (attr_print(stream, ATTR_FLAG_NONE,
SEND_ATTR_STR(MAIL_ATTR_REQ, class),
SEND_ATTR_STR(MAIL_ATTR_SENDER, sender),
SEND_ATTR_STR(MAIL_ATTR_ADDR, addr),
ATTR_TYPE_END) != 0
|| vstream_fflush(stream)
|| attr_scan(stream, ATTR_FLAG_STRICT,
RECV_ATTR_INT(MAIL_ATTR_FLAGS, &server_flags),
RECV_ATTR_STR(MAIL_ATTR_TRANSPORT, reply->transport),
RECV_ATTR_STR(MAIL_ATTR_NEXTHOP, reply->nexthop),
RECV_ATTR_STR(MAIL_ATTR_RECIP, reply->recipient),
RECV_ATTR_INT(MAIL_ATTR_FLAGS, &reply->flags),
ATTR_TYPE_END) != 5) {
if (msg_verbose || count > 1 || (errno && errno != EPIPE && errno != ENOENT))
msg_warn("problem talking to service %s: %m",
var_rewrite_service);
} else {
if (msg_verbose)
msg_info("%s: `%s' -> `%s' -> transp=`%s' host=`%s' rcpt=`%s' flags=%s%s%s%s class=%s%s%s%s%s",
myname, sender, addr, STR(reply->transport),
STR(reply->nexthop), STR(reply->recipient),
IFSET(RESOLVE_FLAG_FINAL, "final"),
IFSET(RESOLVE_FLAG_ROUTED, "routed"),
IFSET(RESOLVE_FLAG_ERROR, "error"),
IFSET(RESOLVE_FLAG_FAIL, "fail"),
IFSET(RESOLVE_CLASS_LOCAL, "local"),
IFSET(RESOLVE_CLASS_ALIAS, "alias"),
IFSET(RESOLVE_CLASS_VIRTUAL, "virtual"),
IFSET(RESOLVE_CLASS_RELAY, "relay"),
IFSET(RESOLVE_CLASS_DEFAULT, "default"));
/* Server-requested disconnect. */
if (server_flags != 0)
clnt_stream_recover(rewrite_clnt_stream);
if (STR(reply->transport)[0] == 0)
msg_warn("%s: null transport result for: <%s>", myname, addr);
else if (STR(reply->recipient)[0] == 0 && *addr != 0)
msg_warn("%s: null recipient result for: <%s>", myname, addr);
else
break;
}
sleep(1); /* XXX make configurable */
clnt_stream_recover(rewrite_clnt_stream);
}
/*
* Update the cache.
*/
vstring_strcpy(last_class, class);
vstring_strcpy(last_sender, sender);
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;
last_expire = time((time_t *) 0) + 30; /* XXX make configurable */
}
/* 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 <split_at.h>
#include <mail_conf.h>
static NORETURN usage(char *myname)
{
msg_fatal("usage: %s [-v] [address...]", myname);
}
static void resolve(char *class, char *addr, RESOLVE_REPLY *reply)
{
struct RESOLVE_FLAG_TABLE {
int flag;
const char *name;
};
struct RESOLVE_FLAG_TABLE resolve_flag_table[] = {
RESOLVE_FLAG_FINAL, "FLAG_FINAL",
RESOLVE_FLAG_ROUTED, "FLAG_ROUTED",
RESOLVE_FLAG_ERROR, "FLAG_ERROR",
RESOLVE_FLAG_FAIL, "FLAG_FAIL",
RESOLVE_CLASS_LOCAL, "CLASS_LOCAL",
RESOLVE_CLASS_ALIAS, "CLASS_ALIAS",
RESOLVE_CLASS_VIRTUAL, "CLASS_VIRTUAL",
RESOLVE_CLASS_RELAY, "CLASS_RELAY",
RESOLVE_CLASS_DEFAULT, "CLASS_DEFAULT",
0,
};
struct RESOLVE_FLAG_TABLE *fp;
resolve_clnt(class, RESOLVE_NULL_FROM, addr, reply);
if (reply->flags & RESOLVE_FLAG_FAIL) {
vstream_printf("request failed\n");
} else {
vstream_printf("%-10s %s\n", "class", class);
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_printf("%-10s ", "flags");
for (fp = resolve_flag_table; fp->name; fp++) {
if (reply->flags & fp->flag) {
vstream_printf("%s ", fp->name);
reply->flags &= ~fp->flag;
}
}
if (reply->flags != 0)
vstream_printf("Unknown flag 0x%x", reply->flags);
vstream_printf("\n\n");
vstream_fflush(VSTREAM_OUT);
}
}
int main(int argc, char **argv)
{
RESOLVE_REPLY reply;
char *addr;
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] && argv[optind + 1]) {
resolve(argv[optind], argv[optind + 1], &reply);
optind += 2;
}
} else {
VSTRING *buffer = vstring_alloc(1);
while (vstring_fgets_nonl(buffer, VSTREAM_IN)) {
addr = split_at(STR(buffer), ' ');
if (*STR(buffer) == 0)
msg_fatal("need as input: class [address]");
if (addr == 0)
addr = "";
resolve(STR(buffer), addr, &reply);
}
vstring_free(buffer);
}
resolve_clnt_free(&reply);
exit(0);
}
#endif