From: Jeremy Harris Date: Mon, 9 Jan 2017 11:46:30 +0000 (+0000) Subject: Split out callout-cache handling from do_callout() X-Git-Tag: exim-4_89_RC1~30^2~5 X-Git-Url: https://git.exim.org/exim.git/commitdiff_plain/707ee5b1b5a4dc605242e95e988022b87514ce6b Split out callout-cache handling from do_callout() --- diff --git a/src/src/verify.c b/src/src/verify.c index 4af863c0b..def9b31a8 100644 --- a/src/src/verify.c +++ b/src/src/verify.c @@ -119,97 +119,21 @@ return cache_record; -/************************************************* -* Do callout verification for an address * -*************************************************/ - -/* This function is called from verify_address() when the address has routed to -a host list, and a callout has been requested. Callouts are expensive; that is -why a cache is used to improve the efficiency. - -Arguments: - addr the address that's been routed - host_list the list of hosts to try - tf the transport feedback block - - ifstring "interface" option from transport, or NULL - portstring "port" option from transport, or NULL - protocolstring "protocol" option from transport, or NULL - callout the per-command callout timeout - callout_overall the overall callout timeout (if < 0 use 4*callout) - callout_connect the callout connection timeout (if < 0 use callout) - options the verification options - these bits are used: - vopt_is_recipient => this is a recipient address - vopt_callout_no_cache => don't use callout cache - vopt_callout_fullpm => if postmaster check, do full one - vopt_callout_random => do the "random" thing - vopt_callout_recipsender => use real sender for recipient - vopt_callout_recippmaster => use postmaster for recipient - se_mailfrom MAIL FROM address for sender verify; NULL => "" - pm_mailfrom if non-NULL, do the postmaster check with this sender +/* Check the callout cache. +Options * pm_mailfrom may be modified by cache partial results. -Returns: OK/FAIL/DEFER +Return: TRUE if result found */ -static int -do_callout(address_item *addr, host_item *host_list, transport_feedback *tf, - int callout, int callout_overall, int callout_connect, int options, - uschar *se_mailfrom, uschar *pm_mailfrom) +static BOOL +cached_callout_lookup(address_item * addr, uschar * address_key, + uschar * from_address, int * opt_ptr, uschar ** pm_ptr, + int * yield, uschar ** failure_ptr, + dbdata_callout_cache * new_domain_record, int * old_domain_res) { -int yield = OK; -int old_domain_cache_result = ccache_accept; -BOOL done = FALSE; -uschar *address_key; -uschar *from_address; -uschar *random_local_part = NULL; -const uschar *save_deliver_domain = deliver_domain; -uschar **failure_ptr = options & vopt_is_recipient - ? &recipient_verify_failure : &sender_verify_failure; +int options = *opt_ptr; open_db dbblock; open_db *dbm_file = NULL; -dbdata_callout_cache new_domain_record; -dbdata_callout_cache_address new_address_record; -host_item *host; -time_t callout_start_time; - -new_domain_record.result = ccache_unknown; -new_domain_record.postmaster_result = ccache_unknown; -new_domain_record.random_result = ccache_unknown; - -memset(&new_address_record, 0, sizeof(new_address_record)); - -/* For a recipient callout, the key used for the address cache record must -include the sender address if we are using the real sender in the callout, -because that may influence the result of the callout. */ - -address_key = addr->address; -from_address = US""; - -if (options & vopt_is_recipient) - { - if (options & vopt_callout_recipsender) - { - address_key = string_sprintf("%s/<%s>", addr->address, sender_address); - from_address = sender_address; - if (cutthrough.delivery) options |= vopt_callout_no_cache; - } - else if (options & vopt_callout_recippmaster) - { - address_key = string_sprintf("%s/", addr->address, - qualify_domain_sender); - from_address = string_sprintf("postmaster@%s", qualify_domain_sender); - } - } - -/* For a sender callout, we must adjust the key if the mailfrom address is not -empty. */ - -else - { - from_address = (se_mailfrom == NULL)? US"" : se_mailfrom; - if (from_address[0] != 0) - address_key = string_sprintf("%s/<%s>", addr->address, from_address); - } /* Open the callout cache database, it it exists, for reading only at this stage, unless caching has been disabled. */ @@ -218,21 +142,19 @@ if (options & vopt_callout_no_cache) { HDEBUG(D_verify) debug_printf("callout cache: disabled by no_cache\n"); } -else if ((dbm_file = dbfn_open(US"callout", O_RDWR, &dbblock, FALSE)) == NULL) +else if (!(dbm_file = dbfn_open(US"callout", O_RDWR, &dbblock, FALSE))) { HDEBUG(D_verify) debug_printf("callout cache: not available\n"); } - -/* If a cache database is available see if we can avoid the need to do an -actual callout by making use of previously-obtained data. */ - -if (dbm_file) +else { - dbdata_callout_cache_address *cache_address_record; - dbdata_callout_cache *cache_record = get_callout_cache_record(dbm_file, - addr->domain, US"domain", - callout_cache_domain_positive_expire, - callout_cache_domain_negative_expire); + /* If a cache database is available see if we can avoid the need to do an + actual callout by making use of previously-obtained data. */ + + dbdata_callout_cache_address * cache_address_record; + dbdata_callout_cache * cache_record = get_callout_cache_record(dbm_file, + addr->domain, US"domain", + callout_cache_domain_positive_expire, callout_cache_domain_negative_expire); /* If an unexpired cache record was found for this domain, see if the callout process can be short-circuited. */ @@ -247,20 +169,21 @@ if (dbm_file) not to disturb the cached domain value if this whole verification succeeds (we don't want it turning into "accept"). */ - old_domain_cache_result = cache_record->result; + *old_domain_res = cache_record->result; - if (cache_record->result == ccache_reject || - (*from_address == 0 && cache_record->result == ccache_reject_mfnull)) + if ( cache_record->result == ccache_reject + || *from_address == 0 && cache_record->result == ccache_reject_mfnull) { setflag(addr, af_verify_nsfail); HDEBUG(D_verify) - debug_printf("callout cache: domain gave initial rejection, or " - "does not accept HELO or MAIL FROM:<>\n"); + debug_printf("callout cache: domain gave initial rejection, or " + "does not accept HELO or MAIL FROM:<>\n"); setflag(addr, af_verify_nsfail); addr->user_message = US"(result of an earlier callout reused)."; - yield = FAIL; + *yield = FAIL; *failure_ptr = US"mail"; - goto END_CALLOUT; + dbfn_close(dbm_file); + return TRUE; } /* If a previous check on a "random" local part was accepted, we assume @@ -275,21 +198,23 @@ if (dbm_file) case ccache_accept: HDEBUG(D_verify) debug_printf("callout cache: domain accepts random addresses\n"); - goto END_CALLOUT; /* Default yield is OK */ + dbfn_close(dbm_file); + return TRUE; /* Default yield is OK */ case ccache_reject: HDEBUG(D_verify) debug_printf("callout cache: domain rejects random addresses\n"); - options &= ~vopt_callout_random; - new_domain_record.random_result = ccache_reject; - new_domain_record.random_stamp = cache_record->random_stamp; + *opt_ptr = options & ~vopt_callout_random; + new_domain_record->random_result = ccache_reject; + new_domain_record->random_stamp = cache_record->random_stamp; break; default: HDEBUG(D_verify) debug_printf("callout cache: need to check random address handling " "(not cached or cache expired)\n"); - goto END_CACHE; + dbfn_close(dbm_file); + return FALSE; } /* If a postmaster check is requested, but there was a previous failure, @@ -297,27 +222,29 @@ if (dbm_file) but has not been done before, we are going to have to do a callout, so skip remaining cache processing. */ - if (pm_mailfrom) + if (*pm_ptr) { if (cache_record->postmaster_result == ccache_reject) - { - setflag(addr, af_verify_pmfail); - HDEBUG(D_verify) - debug_printf("callout cache: domain does not accept " - "RCPT TO:\n"); - yield = FAIL; - *failure_ptr = US"postmaster"; - setflag(addr, af_verify_pmfail); - addr->user_message = US"(result of earlier verification reused)."; - goto END_CALLOUT; - } + { + setflag(addr, af_verify_pmfail); + HDEBUG(D_verify) + debug_printf("callout cache: domain does not accept " + "RCPT TO:\n"); + *yield = FAIL; + *failure_ptr = US"postmaster"; + setflag(addr, af_verify_pmfail); + addr->user_message = US"(result of earlier verification reused)."; + dbfn_close(dbm_file); + return TRUE; + } if (cache_record->postmaster_result == ccache_unknown) - { - HDEBUG(D_verify) - debug_printf("callout cache: need to check RCPT " - "TO: (not cached or cache expired)\n"); - goto END_CACHE; - } + { + HDEBUG(D_verify) + debug_printf("callout cache: need to check RCPT " + "TO: (not cached or cache expired)\n"); + dbfn_close(dbm_file); + return FALSE; + } /* If cache says OK, set pm_mailfrom NULL to prevent a redundant postmaster check if the address itself has to be checked. Also ensure @@ -325,10 +252,10 @@ if (dbm_file) */ HDEBUG(D_verify) debug_printf("callout cache: domain accepts RCPT " - "TO:\n"); - pm_mailfrom = NULL; - new_domain_record.postmaster_result = ccache_accept; - new_domain_record.postmaster_stamp = cache_record->postmaster_stamp; + "TO:\n"); + *pm_ptr = NULL; + new_domain_record->postmaster_result = ccache_accept; + new_domain_record->postmaster_stamp = cache_record->postmaster_stamp; } } @@ -337,36 +264,192 @@ if (dbm_file) sender address if we are doing a recipient callout with a non-empty sender). */ - cache_address_record = (dbdata_callout_cache_address *) - get_callout_cache_record(dbm_file, - address_key, US"address", - callout_cache_positive_expire, - callout_cache_negative_expire); + if (!(cache_address_record = (dbdata_callout_cache_address *) + get_callout_cache_record(dbm_file, address_key, US"address", + callout_cache_positive_expire, callout_cache_negative_expire))) + { + dbfn_close(dbm_file); + return FALSE; + } - if (cache_address_record) + if (cache_address_record->result == ccache_accept) { - if (cache_address_record->result == ccache_accept) - { - HDEBUG(D_verify) - debug_printf("callout cache: address record is positive\n"); - } - else - { - HDEBUG(D_verify) - debug_printf("callout cache: address record is negative\n"); - addr->user_message = US"Previous (cached) callout verification failure"; - *failure_ptr = US"recipient"; - yield = FAIL; - } - goto END_CALLOUT; + HDEBUG(D_verify) + debug_printf("callout cache: address record is positive\n"); + } + else + { + HDEBUG(D_verify) + debug_printf("callout cache: address record is negative\n"); + addr->user_message = US"Previous (cached) callout verification failure"; + *failure_ptr = US"recipient"; + *yield = FAIL; } /* Close the cache database while we actually do the callout for real. */ - END_CACHE: dbfn_close(dbm_file); - dbm_file = NULL; + return TRUE; } +return FALSE; +} + + +/* Write results to callout cache +*/ +static void +cache_callout_write(dbdata_callout_cache * dom_rec, const uschar * domain, + int done, dbdata_callout_cache_address * addr_rec, uschar * address_key) +{ +open_db dbblock; +open_db *dbm_file = NULL; + +/* If we get here with done == TRUE, a successful callout happened, and yield +will be set OK or FAIL according to the response to the RCPT command. +Otherwise, we looped through the hosts but couldn't complete the business. +However, there may be domain-specific information to cache in both cases. + +The value of the result field in the new_domain record is ccache_unknown if +there was an error before or with MAIL FROM:, and errno was not zero, +implying some kind of I/O error. We don't want to write the cache in that case. +Otherwise the value is ccache_accept, ccache_reject, or ccache_reject_mfnull. */ + +if (dom_rec->result != ccache_unknown) + if (!(dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE))) + { + HDEBUG(D_verify) debug_printf("callout cache: not available\n"); + } + else + { + (void)dbfn_write(dbm_file, domain, dom_rec, + (int)sizeof(dbdata_callout_cache)); + HDEBUG(D_verify) debug_printf("wrote callout cache domain record for %s:\n" + " result=%d postmaster=%d random=%d\n", + domain, + dom_rec->result, + dom_rec->postmaster_result, + dom_rec->random_result); + } + +/* If a definite result was obtained for the callout, cache it unless caching +is disabled. */ + +if (done && addr_rec->result != ccache_unknown) + { + if (!dbm_file) + dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE); + if (!dbm_file) + { + HDEBUG(D_verify) debug_printf("no callout cache available\n"); + } + else + { + (void)dbfn_write(dbm_file, address_key, addr_rec, + (int)sizeof(dbdata_callout_cache_address)); + HDEBUG(D_verify) debug_printf("wrote %s callout cache address record for %s\n", + addr_rec->result == ccache_accept ? "positive" : "negative", + address_key); + } + } + +if (dbm_file) dbfn_close(dbm_file); +} + + +/************************************************* +* Do callout verification for an address * +*************************************************/ + +/* This function is called from verify_address() when the address has routed to +a host list, and a callout has been requested. Callouts are expensive; that is +why a cache is used to improve the efficiency. + +Arguments: + addr the address that's been routed + host_list the list of hosts to try + tf the transport feedback block + + ifstring "interface" option from transport, or NULL + portstring "port" option from transport, or NULL + protocolstring "protocol" option from transport, or NULL + callout the per-command callout timeout + callout_overall the overall callout timeout (if < 0 use 4*callout) + callout_connect the callout connection timeout (if < 0 use callout) + options the verification options - these bits are used: + vopt_is_recipient => this is a recipient address + vopt_callout_no_cache => don't use callout cache + vopt_callout_fullpm => if postmaster check, do full one + vopt_callout_random => do the "random" thing + vopt_callout_recipsender => use real sender for recipient + vopt_callout_recippmaster => use postmaster for recipient + se_mailfrom MAIL FROM address for sender verify; NULL => "" + pm_mailfrom if non-NULL, do the postmaster check with this sender + +Returns: OK/FAIL/DEFER +*/ + +static int +do_callout(address_item *addr, host_item *host_list, transport_feedback *tf, + int callout, int callout_overall, int callout_connect, int options, + uschar *se_mailfrom, uschar *pm_mailfrom) +{ +int yield = OK; +int old_domain_cache_result = ccache_accept; +BOOL done = FALSE; +uschar *address_key; +uschar *from_address; +uschar *random_local_part = NULL; +const uschar *save_deliver_domain = deliver_domain; +uschar **failure_ptr = options & vopt_is_recipient + ? &recipient_verify_failure : &sender_verify_failure; +dbdata_callout_cache new_domain_record; +dbdata_callout_cache_address new_address_record; +host_item *host; +time_t callout_start_time; + +new_domain_record.result = ccache_unknown; +new_domain_record.postmaster_result = ccache_unknown; +new_domain_record.random_result = ccache_unknown; + +memset(&new_address_record, 0, sizeof(new_address_record)); + +/* For a recipient callout, the key used for the address cache record must +include the sender address if we are using the real sender in the callout, +because that may influence the result of the callout. */ + +if (options & vopt_is_recipient) + if (options & vopt_callout_recipsender) + { + from_address = sender_address; + address_key = string_sprintf("%s/<%s>", addr->address, sender_address); + if (cutthrough.delivery) options |= vopt_callout_no_cache; + } + else if (options & vopt_callout_recippmaster) + { + from_address = string_sprintf("postmaster@%s", qualify_domain_sender); + address_key = string_sprintf("%s/", addr->address, + qualify_domain_sender); + } + else + { + from_address = US""; + address_key = addr->address; + } + +/* For a sender callout, we must adjust the key if the mailfrom address is not +empty. */ + +else + { + from_address = se_mailfrom ? se_mailfrom : US""; + address_key = *from_address + ? string_sprintf("%s/<%s>", addr->address, from_address) : addr->address; + } + +if (cached_callout_lookup(addr, address_key, from_address, + &options, &pm_mailfrom, &yield, failure_ptr, + &new_domain_record, &old_domain_cache_result)) + goto END_CALLOUT; if (!addr->transport) { @@ -386,7 +469,7 @@ else with a random local part, ensure that such a local part is available. If not, log the fact, but carry on without randomising. */ - if (options & vopt_callout_random && callout_random_local_part != NULL) + if (options & vopt_callout_random && callout_random_local_part) if (!(random_local_part = expand_string(callout_random_local_part))) log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand " "callout_random_local_part: %s", expand_string_message); @@ -703,9 +786,8 @@ tls_retry_connection: } #endif - new_domain_record.result = - (old_domain_cache_result == ccache_reject_mfnull)? - ccache_reject_mfnull: ccache_accept; + new_domain_record.result = old_domain_cache_result == ccache_reject_mfnull + ? ccache_reject_mfnull : ccache_accept; /* Do the random local part check first */ @@ -1007,64 +1089,17 @@ no_conn: /* If we get here with done == TRUE, a successful callout happened, and yield will be set OK or FAIL according to the response to the RCPT command. Otherwise, we looped through the hosts but couldn't complete the business. -However, there may be domain-specific information to cache in both cases. +However, there may be domain-specific information to cache in both cases. */ -The value of the result field in the new_domain record is ccache_unknown if -there was an error before or with MAIL FROM:, and errno was not zero, -implying some kind of I/O error. We don't want to write the cache in that case. -Otherwise the value is ccache_accept, ccache_reject, or ccache_reject_mfnull. */ - -if ( !(options & vopt_callout_no_cache) - && new_domain_record.result != ccache_unknown) - { - if ((dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE)) - == NULL) - { - HDEBUG(D_verify) debug_printf("callout cache: not available\n"); - } - else - { - (void)dbfn_write(dbm_file, addr->domain, &new_domain_record, - (int)sizeof(dbdata_callout_cache)); - HDEBUG(D_verify) debug_printf("wrote callout cache domain record for %s:\n" - " result=%d postmaster=%d random=%d\n", - addr->domain, - new_domain_record.result, - new_domain_record.postmaster_result, - new_domain_record.random_result); - } - } - -/* If a definite result was obtained for the callout, cache it unless caching -is disabled. */ - -if (done) - { - if ( !(options & vopt_callout_no_cache) - && new_address_record.result != ccache_unknown) - { - if (!dbm_file) - dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE); - if (!dbm_file) - { - HDEBUG(D_verify) debug_printf("no callout cache available\n"); - } - else - { - (void)dbfn_write(dbm_file, address_key, &new_address_record, - (int)sizeof(dbdata_callout_cache_address)); - HDEBUG(D_verify) debug_printf("wrote %s callout cache address record for %s\n", - new_address_record.result == ccache_accept ? "positive" : "negative", - address_key); - } - } - } /* done */ +if (!(options & vopt_callout_no_cache)) + cache_callout_write(&new_domain_record, addr->domain, + done, &new_address_record, address_key); /* Failure to connect to any host, or any response other than 2xx or 5xx is a temporary error. If there was only one host, and a response was received, leave it alone if supplying details. Otherwise, give a generic response. */ -else /* !done */ +if (!done) { uschar * dullmsg = string_sprintf("Could not complete %s verify callout", options & vopt_is_recipient ? "recipient" : "sender"); @@ -1093,7 +1128,6 @@ else /* !done */ /* Come here from within the cache-reading code on fast-track exit. */ END_CALLOUT: -if (dbm_file) dbfn_close(dbm_file); tls_modify_variables(&tls_in); return yield; }