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-rw-r--r--src/global/resolve_clnt.c408
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diff --git a/src/global/resolve_clnt.c b/src/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_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
+/*
+/* Wietse Venema
+/* Google, Inc.
+/* 111 8th Avenue
+/* New York, NY 10011, 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_handshake - receive server protocol announcement */
+
+static int resolve_clnt_handshake(VSTREAM *stream)
+{
+ return (attr_scan(stream, ATTR_FLAG_STRICT,
+ RECV_ATTR_STREQ(MAIL_ATTR_PROTO, MAIL_ATTR_PROTO_TRIVIAL),
+ ATTR_TYPE_END));
+}
+
+/* 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,
+ resolve_clnt_handshake);
+
+ for (;;) {
+ stream = clnt_stream_access(rewrite_clnt_stream);
+ errno = 0;
+ count += 1;
+ if (stream == 0
+ || 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