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-rw-r--r--src/smtpd/smtpd_resolve.c190
1 files changed, 190 insertions, 0 deletions
diff --git a/src/smtpd/smtpd_resolve.c b/src/smtpd/smtpd_resolve.c
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+++ b/src/smtpd/smtpd_resolve.c
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+/*++
+/* NAME
+/* smtpd_resolve 3
+/* SUMMARY
+/* caching resolve client
+/* SYNOPSIS
+/* #include <smtpd_resolve.h>
+/*
+/* void smtpd_resolve_init(cache_size)
+/* int cache_size;
+/*
+/* const RESOLVE_REPLY *smtpd_resolve_addr(sender, addr)
+/* const char *sender;
+/* const char *addr;
+/* DESCRIPTION
+/* This module maintains a resolve client cache that persists
+/* across SMTP sessions (not process life times). Addresses
+/* are always resolved in local rewriting context.
+/*
+/* smtpd_resolve_init() initializes the cache and must be
+/* called before the cache can be used. This function may also
+/* be called to flush the cache after an address class update.
+/*
+/* smtpd_resolve_addr() resolves one address or returns
+/* a known result from cache.
+/*
+/* Arguments:
+/* .IP cache_size
+/* The requested cache size.
+/* .IP sender
+/* The message sender, or null pointer.
+/* .IP addr
+/* The address to resolve.
+/* DIAGNOSTICS
+/* All errors are fatal.
+/* BUGS
+/* The recipient address is always case folded to lowercase.
+/* Changing this requires great care, since the address is used
+/* for policy lookups.
+/* 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>
+
+/* Utility library. */
+
+#include <msg.h>
+#include <mymalloc.h>
+#include <vstring.h>
+#include <ctable.h>
+#include <stringops.h>
+#include <split_at.h>
+
+/* Global library. */
+
+#include <rewrite_clnt.h>
+#include <resolve_clnt.h>
+#include <mail_proto.h>
+
+/* Application-specific. */
+
+#include <smtpd_resolve.h>
+
+static CTABLE *smtpd_resolve_cache;
+
+#define STR(x) vstring_str(x)
+#define SENDER_ADDR_JOIN_CHAR '\n'
+
+/* resolve_pagein - page in an address resolver result */
+
+static void *resolve_pagein(const char *sender_plus_addr, void *unused_context)
+{
+ const char myname[] = "resolve_pagein";
+ static VSTRING *query;
+ static VSTRING *junk;
+ static VSTRING *sender_buf;
+ RESOLVE_REPLY *reply;
+ const char *sender;
+ const char *addr;
+
+ /*
+ * Initialize on the fly.
+ */
+ if (query == 0) {
+ query = vstring_alloc(10);
+ junk = vstring_alloc(10);
+ sender_buf = vstring_alloc(10);
+ }
+
+ /*
+ * Initialize.
+ */
+ reply = (RESOLVE_REPLY *) mymalloc(sizeof(*reply));
+ resolve_clnt_init(reply);
+
+ /*
+ * Split the sender and address.
+ */
+ vstring_strcpy(junk, sender_plus_addr);
+ sender = STR(junk);
+ if ((addr = split_at(STR(junk), SENDER_ADDR_JOIN_CHAR)) == 0)
+ msg_panic("%s: bad search key: \"%s\"", myname, sender_plus_addr);
+
+ /*
+ * Resolve the address.
+ */
+ rewrite_clnt_internal(MAIL_ATTR_RWR_LOCAL, sender, sender_buf);
+ rewrite_clnt_internal(MAIL_ATTR_RWR_LOCAL, addr, query);
+ resolve_clnt_query_from(STR(sender_buf), STR(query), reply);
+ vstring_strcpy(junk, STR(reply->recipient));
+ casefold(reply->recipient, STR(junk)); /* XXX */
+
+ /*
+ * Save the result.
+ */
+ return ((void *) reply);
+}
+
+/* resolve_pageout - page out an address resolver result */
+
+static void resolve_pageout(void *data, void *unused_context)
+{
+ RESOLVE_REPLY *reply = (RESOLVE_REPLY *) data;
+
+ resolve_clnt_free(reply);
+ myfree((void *) reply);
+}
+
+/* smtpd_resolve_init - set up global cache */
+
+void smtpd_resolve_init(int cache_size)
+{
+
+ /*
+ * Flush a pre-existing cache. The smtpd_check test program requires this
+ * after an address class change.
+ */
+ if (smtpd_resolve_cache)
+ ctable_free(smtpd_resolve_cache);
+
+ /*
+ * Initialize the resolved address cache. Note: the cache persists across
+ * SMTP sessions so we cannot make it dependent on session state.
+ */
+ smtpd_resolve_cache = ctable_create(cache_size, resolve_pagein,
+ resolve_pageout, (void *) 0);
+}
+
+/* smtpd_resolve_addr - resolve cached address */
+
+const RESOLVE_REPLY *smtpd_resolve_addr(const char *sender, const char *addr)
+{
+ static VSTRING *sender_plus_addr_buf;
+
+ /*
+ * Initialize on the fly.
+ */
+ if (sender_plus_addr_buf == 0)
+ sender_plus_addr_buf = vstring_alloc(10);
+
+ /*
+ * Sanity check.
+ */
+ if (smtpd_resolve_cache == 0)
+ msg_panic("smtpd_resolve_addr: missing initialization");
+
+ /*
+ * Reply from the read-through cache.
+ */
+ vstring_sprintf(sender_plus_addr_buf, "%s%c%s",
+ sender ? sender : RESOLVE_NULL_FROM,
+ SENDER_ADDR_JOIN_CHAR, addr);
+ return (const RESOLVE_REPLY *)
+ ctable_locate(smtpd_resolve_cache, STR(sender_plus_addr_buf));
+}