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Diffstat (limited to 'src/smtpd/smtpd_resolve.c')
| -rw-r--r-- | src/smtpd/smtpd_resolve.c | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/src/smtpd/smtpd_resolve.c b/src/smtpd/smtpd_resolve.c new file mode 100644 index 0000000..1dd6914 --- /dev/null +++ b/src/smtpd/smtpd_resolve.c @@ -0,0 +1,190 @@ +/*++ +/* 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)); +} |