diff -r -U3 exim-4.30/doc/spec.txt exim-4.30.helo.cache/doc/spec.txt --- exim-4.30/doc/spec.txt Mon Dec 1 10:15:41 2003 +++ exim-4.30.helo.cache/doc/spec.txt Wed Mar 3 10:26:18 2004 @@ -8282,6 +8282,12 @@ general expansion strings, and provokes an 'unknown variable' error if encountered. +$previous_sender_helo_name: When a message is received from a remote host that + has issued a HELO or EHLO command, the previously cached value of the + argument is placed in this variable. If there was no previously cached value, + or "helo_cache" is not set in the configuration then the variable is not + defined. The behaviour of this variable applies only to remote SMTP input. + $primary_hostname: The value set in the configuration file, or read by the "uname()" function. If "uname()" returns a single-component name, Exim calls "gethostbyname()" (or "getipnodebyname()" where available) in an attempt to @@ -9851,6 +9857,19 @@ helo_allow_chars = _ Note that the value is one string, not a list. + +helo_cache Type: boolean Default: false + + If this option is set, the arguments received from remote hosts to HELO + and EHLO commands are cached. Previously cached values of the arguments + are available in the "$previous_sender_helo_name". The IP address of the + sending host is used as the key. + +helo_cache_expire Type: time Default: 1h + + When "helo_cache" is used to cache arguments to HELO/EHLO commands, this + value defines for how long Exim should remember the values after the most + recent HELO/EHLO command from a particular host. helo_lookup_domains Type: domain list* Default: @:@[] Only in exim-4.30.helo.cache/src: clarauser-exim-4.30.diff diff -r -U3 exim-4.30/src/dbstuff.h exim-4.30.helo.cache/src/dbstuff.h --- exim-4.30/src/dbstuff.h Mon Dec 1 10:15:41 2003 +++ exim-4.30.helo.cache/src/dbstuff.h Tue Mar 2 20:30:31 2004 @@ -628,5 +628,16 @@ int count; /* Reserved for possible connection count */ } dbdata_serialize; +/* This structure records how hosts identify themselves by HELO/EHLO. The key +is the IP address of the connecting host. */ + +typedef struct { + time_t time_stamp; + /*************/ + BOOL expired; /* Item has expired */ + uschar helo[1]; /* Host identifier */ +} dbdata_helo_cache; + + /* End of dbstuff.h */ diff -r -U3 exim-4.30/src/exim_dbutil.c exim-4.30.helo.cache/src/exim_dbutil.c --- exim-4.30/src/exim_dbutil.c Mon Dec 1 10:15:41 2003 +++ exim-4.30.helo.cache/src/exim_dbutil.c Wed Mar 3 10:15:42 2004 @@ -65,6 +65,7 @@ #define type_wait 2 #define type_misc 3 #define type_callout 4 +#define type_helo 5 @@ -111,7 +112,7 @@ usage(uschar *name, uschar *options) { printf("Usage: exim_%s%s \n", name, options); -printf(" = retry | misc | wait- | callout\n"); +printf(" = retry | misc | wait- | callout | helo\n"); exit(1); } @@ -133,6 +134,7 @@ if (Ustrcmp(argv[2], "misc") == 0) return type_misc; if (Ustrncmp(argv[2], "wait-", 5) == 0) return type_wait; if (Ustrcmp(argv[2], "callout") == 0) return type_callout; + if (Ustrcmp(argv[2], "helo") == 0) return type_helo; } usage(name, options); return -1; /* Never obeyed */ @@ -534,6 +536,7 @@ dbdata_retry *retry; dbdata_wait *wait; dbdata_callout_cache *callout; + dbdata_helo_cache *helo; int count_bad = 0; int i, length; uschar *t; @@ -659,6 +662,11 @@ print_cache(callout->random_result)); } + break; + + case type_helo: + helo = (dbdata_helo_cache *)value; + printf(" %s %s\n", keybuffer, helo->helo); break; } store_reset(value); diff -r -U3 exim-4.30/src/expand.c exim-4.30.helo.cache/src/expand.c --- exim-4.30/src/expand.c Mon Dec 1 10:15:41 2003 +++ exim-4.30.helo.cache/src/expand.c Wed Mar 3 10:28:39 2004 @@ -276,6 +276,7 @@ { "parent_domain", vtype_stringptr, &deliver_domain_parent }, { "parent_local_part", vtype_stringptr, &deliver_localpart_parent }, { "pid", vtype_pid, NULL }, + { "previous_sender_helo_name",vtype_stringptr, &previous_sender_helo_name }, { "primary_hostname", vtype_stringptr, &primary_hostname }, { "qualify_domain", vtype_stringptr, &qualify_domain_sender }, { "qualify_recipient", vtype_stringptr, &qualify_domain_recipient }, diff -r -U3 exim-4.30/src/globals.c exim-4.30.helo.cache/src/globals.c --- exim-4.30/src/globals.c Mon Dec 1 10:15:41 2003 +++ exim-4.30.helo.cache/src/globals.c Wed Mar 3 10:19:20 2004 @@ -490,6 +490,8 @@ BOOL header_rewritten = FALSE; uschar *helo_accept_junk_hosts = NULL; uschar *helo_allow_chars = US""; +BOOL helo_cache = FALSE; +int helo_cache_expire = 60*60; /* 1 hour */ uschar *helo_lookup_domains = US"@ : @[]"; uschar *helo_try_verify_hosts = NULL; BOOL helo_verified = FALSE; @@ -629,6 +631,7 @@ "\0<--------------Space to patch pid_file_path->"; uschar *pipelining_advertise_hosts = US"*"; BOOL preserve_message_logs = FALSE; +uschar *previous_sender_helo_name = NULL; uschar *primary_hostname = NULL; uschar *primary_hostname_lc = NULL; BOOL print_topbitchars = FALSE; diff -r -U3 exim-4.30/src/globals.h exim-4.30.helo.cache/src/globals.h --- exim-4.30/src/globals.h Mon Dec 1 10:15:41 2003 +++ exim-4.30.helo.cache/src/globals.h Wed Mar 3 10:07:57 2004 @@ -277,6 +277,8 @@ extern BOOL header_rewritten; /* TRUE if header changed by router */ extern uschar *helo_accept_junk_hosts; /* Allowed to use junk arg */ extern uschar *helo_allow_chars; /* Rogue chars to allow in HELO/EHLO */ +extern BOOL helo_cache; /* Whether to cache arguments */ +extern int helo_cache_expire; /* When to expire cached helo data */ extern uschar *helo_lookup_domains; /* If these given, lookup host name */ extern uschar *helo_try_verify_hosts; /* Soft check HELO argument for these */ extern BOOL helo_verified; /* True if HELO verified */ @@ -381,6 +383,7 @@ extern uschar *percent_hack_domains; /* Local domains for which '% operates */ extern uschar *pid_file_path; /* For writing daemon pids */ extern uschar *pipelining_advertise_hosts; /* As it says */ +extern uschar *previous_sender_helo_name; /* Value of previous EHLO/HELO arg */ extern BOOL preserve_message_logs; /* Save msglog files */ extern uschar *primary_hostname; /* Primary name of this computer */ extern uschar *primary_hostname_lc; /* ... lower cased */ diff -r -U3 exim-4.30/src/readconf.c exim-4.30.helo.cache/src/readconf.c --- exim-4.30/src/readconf.c Mon Dec 1 10:15:41 2003 +++ exim-4.30.helo.cache/src/readconf.c Wed Mar 3 10:08:12 2004 @@ -200,6 +200,8 @@ { "headers_charset", opt_stringptr, &headers_charset }, { "helo_accept_junk_hosts", opt_stringptr, &helo_accept_junk_hosts }, { "helo_allow_chars", opt_stringptr, &helo_allow_chars }, + { "helo_cache", opt_bool, &helo_cache }, + { "helo_cache_expire", opt_time, &helo_cache_expire }, { "helo_lookup_domains", opt_stringptr, &helo_lookup_domains }, { "helo_try_verify_hosts", opt_stringptr, &helo_try_verify_hosts }, { "helo_verify_hosts", opt_stringptr, &helo_verify_hosts }, Only in exim-4.30/src: sieve.c.orig diff -r -U3 exim-4.30/src/smtp_in.c exim-4.30.helo.cache/src/smtp_in.c --- exim-4.30/src/smtp_in.c Mon Dec 1 10:15:41 2003 +++ exim-4.30.helo.cache/src/smtp_in.c Wed Mar 3 10:17:38 2004 @@ -644,7 +644,7 @@ /* Check the format of a HELO line. The data for HELO/EHLO is supposed to be the domain name of the sending host, or an ip literal in square brackets. The -arrgument is placed in sender_helo_name, which is in malloc store, because it +argument is placed in sender_helo_name, which is in malloc store, because it must persist over multiple incoming messages. If helo_accept_junk is set, this host is permitted to send any old junk (needed for some broken hosts). Otherwise, helo_allow_chars can be used for rogue characters in general @@ -723,6 +723,111 @@ +/****************************** +* Store a helo cache record * +******************************/ + +/* This function stores a helo cache record using the IP address as a string +as the key and the argument to HELO/EHLO as the value. + +Arguments: + dbmfile pointer to open database handler + address IP address of sender + arg argument to HELO/EHLO + +Returns: nothing +*/ + +static void +write_helo_cache(open_db *dbm_file, uschar *address, uschar *arg) +{ +int message_length; +dbdata_helo_cache *helo_record; + +/* Set up the helo cache record */ +message_length = strlen(arg); +helo_record = store_get(sizeof(dbdata_helo_cache) + message_length); + +Ustrncpy(helo_record->helo, arg, message_length); +helo_record->helo[message_length] = 0; + +DEBUG(D_receive) + { + debug_printf("Writing helo data cache item for %s\n", arg); + debug_printf(" helo argument: %s\n", helo_record->helo); + } + +(void)dbfn_write(dbm_file, address, helo_record, + sizeof(dbdata_helo_cache) + message_length); +} + + + + + +/*************************************************** +* Compare HELO line with previously cached value * +****************************************************/ + +/* Check the value of the HELO line against previously cached value. + +sender_helo_name is not modified by this function. +previous_sender_helo_name contains the last cached HELO argument, if any. + +Mismatches between the two may be checked in ACLs. + +The cache file is updated with every call to this function. + +Argument: + s the data portion of the line (already past any white space) + +Returns: TRUE or FALSE +*/ + +static BOOL same_helo(uschar *address, char *smtp_data) +{ +time_t now = time(NULL); +open_db dbblock; +open_db *dbm_file; +dbdata_helo_cache *helo_record; +BOOL yield; + +if ((dbm_file = dbfn_open(US"helo", O_RDWR, &dbblock, FALSE)) == NULL) + { + DEBUG(D_receive) + debug_printf("no HELO/EHLO cache data available\n"); + return TRUE; + } +helo_record = dbfn_read(dbm_file, address); + +/* If no matching record was found, or the record returned was too old +then we yield as if the current argument and the previous argument do match. */ +if (helo_record == NULL || now - helo_record->time_stamp > helo_cache_expire) + { + previous_sender_helo_name = NULL; + yield = TRUE; + } + +/* The cached data is valid, so compare it to what was passed as the +argument to HELO/EHLO. If the value does not match update the cache with +the new value. */ +else + { + previous_sender_helo_name = string_copy_malloc(helo_record->helo); + if (Ustrlen(smtp_data) != Ustrlen(helo_record->helo) || + Ustrcmp(smtp_data, helo_record->helo) != 0) + yield = FALSE; + else + yield = TRUE; + } + +/* Update the cache file with the (possibly new) HELO argument, but more +importantly, the new timestamp. */ +write_helo_cache(dbm_file, address, smtp_data); +dbfn_close(dbm_file); +return yield; +} + /************************************************* * Extract SMTP command option * *************************************************/ @@ -2135,6 +2240,14 @@ break; } + + /* Compare the current HELO/EHLO value from this host to what the host + * identified itself as last time. */ + if (sender_host_address && helo_cache && + !same_helo(sender_host_address, smtp_data)) + log_write(0, LOG_MAIN, "detected change in %s argument from %s " + "(%s -> %s)", hello, host_and_ident(FALSE), previous_sender_helo_name, + sender_helo_name); /* If sender_host_unknown is true, we have got here via the -bs interface, not called from inetd. Otherwise, we are running an IP connection and the