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Diffstat (limited to '')
| -rw-r--r-- | src/verify/verify.c | 776 |
1 files changed, 776 insertions, 0 deletions
diff --git a/src/verify/verify.c b/src/verify/verify.c new file mode 100644 index 0000000..fea131c --- /dev/null +++ b/src/verify/verify.c @@ -0,0 +1,776 @@ +/*++ +/* NAME +/* verify 8 +/* SUMMARY +/* Postfix address verification server +/* SYNOPSIS +/* \fBverify\fR [generic Postfix daemon options] +/* DESCRIPTION +/* The \fBverify\fR(8) address verification server maintains a record +/* of what recipient addresses are known to be deliverable or +/* undeliverable. +/* +/* Addresses are verified by injecting probe messages into the +/* Postfix queue. Probe messages are run through all the routing +/* and rewriting machinery except for final delivery, and are +/* discarded rather than being deferred or bounced. +/* +/* Address verification relies on the answer from the nearest +/* MTA for the specified address, and will therefore not detect +/* all undeliverable addresses. +/* +/* The \fBverify\fR(8) server is designed to run under control +/* by the Postfix +/* master server. It maintains an optional persistent database. +/* To avoid being interrupted by "postfix stop" in the middle +/* of a database update, the process runs in a separate process +/* group. +/* +/* The \fBverify\fR(8) server implements the following requests: +/* .IP "\fBupdate\fI address status text\fR" +/* Update the status and text of the specified address. +/* .IP "\fBquery\fI address\fR" +/* Look up the \fIstatus\fR and \fItext\fR for the specified +/* \fIaddress\fR. +/* If the status is unknown, a probe is sent and an "in progress" +/* status is returned. +/* SECURITY +/* .ad +/* .fi +/* The address verification server is not security-sensitive. It does +/* not talk to the network, and it does not talk to local users. +/* The verify server can run chrooted at fixed low privilege. +/* +/* The address verification server can be coerced to store +/* unlimited amounts of garbage. Limiting the cache expiry +/* time +/* trades one problem (disk space exhaustion) for another +/* one (poor response time to client requests). +/* +/* With Postfix version 2.5 and later, the \fBverify\fR(8) +/* server no longer uses root privileges when opening the +/* \fBaddress_verify_map\fR cache file. The file should now +/* be stored under the Postfix-owned \fBdata_directory\fR. As +/* a migration aid, an attempt to open a cache file under a +/* non-Postfix directory is redirected to the Postfix-owned +/* \fBdata_directory\fR, and a warning is logged. +/* DIAGNOSTICS +/* Problems and transactions are logged to \fBsyslogd\fR(8) +/* or \fBpostlogd\fR(8). +/* BUGS +/* Address verification probe messages add additional traffic +/* to the mail queue. +/* Recipient verification may cause an increased load on +/* down-stream servers in the case of a dictionary attack or +/* a flood of backscatter bounces. +/* Sender address verification may cause your site to be +/* denylisted by some providers. +/* +/* If the persistent database ever gets corrupted then the world +/* comes to an end and human intervention is needed. This violates +/* a basic Postfix principle. +/* CONFIGURATION PARAMETERS +/* .ad +/* .fi +/* Changes to \fBmain.cf\fR are not picked up automatically, +/* as \fBverify\fR(8) +/* processes are long-lived. Use the command "\fBpostfix reload\fR" after +/* a configuration change. +/* +/* The text below provides only a parameter summary. See +/* \fBpostconf\fR(5) for more details including examples. +/* PROBE MESSAGE CONTROLS +/* .ad +/* .fi +/* .IP "\fBaddress_verify_sender ($double_bounce_sender)\fR" +/* The sender address to use in address verification probes; prior +/* to Postfix 2.5 the default was "postmaster". +/* .PP +/* Available with Postfix 2.9 and later: +/* .IP "\fBaddress_verify_sender_ttl (0s)\fR" +/* The time between changes in the time-dependent portion of address +/* verification probe sender addresses. +/* CACHE CONTROLS +/* .ad +/* .fi +/* .IP "\fBaddress_verify_map (see 'postconf -d' output)\fR" +/* Lookup table for persistent address verification status +/* storage. +/* .IP "\fBaddress_verify_positive_expire_time (31d)\fR" +/* The time after which a successful probe expires from the address +/* verification cache. +/* .IP "\fBaddress_verify_positive_refresh_time (7d)\fR" +/* The time after which a successful address verification probe needs +/* to be refreshed. +/* .IP "\fBaddress_verify_negative_cache (yes)\fR" +/* Enable caching of failed address verification probe results. +/* .IP "\fBaddress_verify_negative_expire_time (3d)\fR" +/* The time after which a failed probe expires from the address +/* verification cache. +/* .IP "\fBaddress_verify_negative_refresh_time (3h)\fR" +/* The time after which a failed address verification probe needs to +/* be refreshed. +/* .PP +/* Available with Postfix 2.7 and later: +/* .IP "\fBaddress_verify_cache_cleanup_interval (12h)\fR" +/* The amount of time between \fBverify\fR(8) address verification +/* database cleanup runs. +/* PROBE MESSAGE ROUTING CONTROLS +/* .ad +/* .fi +/* By default, probe messages are delivered via the same route +/* as regular messages. The following parameters can be used to +/* override specific message routing mechanisms. +/* .IP "\fBaddress_verify_relayhost ($relayhost)\fR" +/* Overrides the relayhost parameter setting for address verification +/* probes. +/* .IP "\fBaddress_verify_transport_maps ($transport_maps)\fR" +/* Overrides the transport_maps parameter setting for address verification +/* probes. +/* .IP "\fBaddress_verify_local_transport ($local_transport)\fR" +/* Overrides the local_transport parameter setting for address +/* verification probes. +/* .IP "\fBaddress_verify_virtual_transport ($virtual_transport)\fR" +/* Overrides the virtual_transport parameter setting for address +/* verification probes. +/* .IP "\fBaddress_verify_relay_transport ($relay_transport)\fR" +/* Overrides the relay_transport parameter setting for address +/* verification probes. +/* .IP "\fBaddress_verify_default_transport ($default_transport)\fR" +/* Overrides the default_transport parameter setting for address +/* verification probes. +/* .PP +/* Available in Postfix 2.3 and later: +/* .IP "\fBaddress_verify_sender_dependent_relayhost_maps ($sender_dependent_relayhost_maps)\fR" +/* Overrides the sender_dependent_relayhost_maps parameter setting for address +/* verification probes. +/* .PP +/* Available in Postfix 2.7 and later: +/* .IP "\fBaddress_verify_sender_dependent_default_transport_maps ($sender_dependent_default_transport_maps)\fR" +/* Overrides the sender_dependent_default_transport_maps parameter +/* setting for address verification probes. +/* SMTPUTF8 CONTROLS +/* .ad +/* .fi +/* Preliminary SMTPUTF8 support is introduced with Postfix 3.0. +/* .IP "\fBsmtputf8_autodetect_classes (sendmail, verify)\fR" +/* Detect that a message requires SMTPUTF8 support for the specified +/* mail origin classes. +/* .PP +/* Available in Postfix version 3.2 and later: +/* .IP "\fBenable_idna2003_compatibility (no)\fR" +/* Enable 'transitional' compatibility between IDNA2003 and IDNA2008, +/* when converting UTF-8 domain names to/from the ASCII form that is +/* used for DNS lookups. +/* MISCELLANEOUS CONTROLS +/* .ad +/* .fi +/* .IP "\fBconfig_directory (see 'postconf -d' output)\fR" +/* The default location of the Postfix main.cf and master.cf +/* configuration files. +/* .IP "\fBdaemon_timeout (18000s)\fR" +/* How much time a Postfix daemon process may take to handle a +/* request before it is terminated by a built-in watchdog timer. +/* .IP "\fBipc_timeout (3600s)\fR" +/* The time limit for sending or receiving information over an internal +/* communication channel. +/* .IP "\fBprocess_id (read-only)\fR" +/* The process ID of a Postfix command or daemon process. +/* .IP "\fBprocess_name (read-only)\fR" +/* The process name of a Postfix command or daemon process. +/* .IP "\fBqueue_directory (see 'postconf -d' output)\fR" +/* The location of the Postfix top-level queue directory. +/* .IP "\fBsyslog_facility (mail)\fR" +/* The syslog facility of Postfix logging. +/* .IP "\fBsyslog_name (see 'postconf -d' output)\fR" +/* A prefix that is prepended to the process name in syslog +/* records, so that, for example, "smtpd" becomes "prefix/smtpd". +/* .PP +/* Available in Postfix 3.3 and later: +/* .IP "\fBservice_name (read-only)\fR" +/* The master.cf service name of a Postfix daemon process. +/* SEE ALSO +/* smtpd(8), Postfix SMTP server +/* cleanup(8), enqueue Postfix message +/* postconf(5), configuration parameters +/* postlogd(8), Postfix logging +/* syslogd(8), system logging +/* README FILES +/* .ad +/* .fi +/* Use "\fBpostconf readme_directory\fR" or +/* "\fBpostconf html_directory\fR" to locate this information. +/* .na +/* .nf +/* ADDRESS_VERIFICATION_README, address verification howto +/* LICENSE +/* .ad +/* .fi +/* The Secure Mailer license must be distributed with this software. +/* HISTORY +/* .ad +/* .fi +/* This service was introduced with Postfix version 2.1. +/* 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 <sys/stat.h> +#include <time.h> +#include <string.h> +#include <stdlib.h> +#include <unistd.h> + +/* Utility library. */ + +#include <msg.h> +#include <mymalloc.h> +#include <htable.h> +#include <dict_ht.h> +#include <dict_cache.h> +#include <split_at.h> +#include <stringops.h> +#include <set_eugid.h> +#include <events.h> + +/* Global library. */ + +#include <mail_conf.h> +#include <mail_params.h> +#include <mail_version.h> +#include <mail_proto.h> +#include <post_mail.h> +#include <data_redirect.h> +#include <verify_clnt.h> +#include <verify_sender_addr.h> + +/* Server skeleton. */ + +#include <mail_server.h> + +/* Application-specific. */ + + /* + * Tunable parameters. + */ +char *var_verify_map; +int var_verify_pos_exp; +int var_verify_pos_try; +int var_verify_neg_exp; +int var_verify_neg_try; +int var_verify_scan_cache; + + /* + * State. + */ +static DICT_CACHE *verify_map; + + /* + * Silly little macros. + */ +#define STR(x) vstring_str(x) +#define STREQ(x,y) (strcmp(x,y) == 0) + + /* + * The address verification database consists of (address, data) tuples. The + * format of the data field is "status:probed:updated:text". The meaning of + * each field is: + * + * status: one of the four recipient status codes (OK, DEFER, BOUNCE or TODO). + * In the case of TODO, we have no information about the address, and the + * address is being probed. + * + * probed: if non-zero, the time the currently outstanding address probe was + * sent. If zero, there is no outstanding address probe. + * + * updated: if non-zero, the time the address probe result was received. If + * zero, we have no information about the address, and the address is being + * probed. + * + * text: descriptive text from delivery agents etc. + */ + + /* + * Quick test to see status without parsing the whole entry. + */ +#define STATUS_FROM_RAW_ENTRY(e) atoi(e) + +/* verify_make_entry - construct table entry */ + +static void verify_make_entry(VSTRING *buf, int status, long probed, + long updated, const char *text) +{ + vstring_sprintf(buf, "%d:%ld:%ld:%s", status, probed, updated, text); +} + +/* verify_parse_entry - parse table entry */ + +static int verify_parse_entry(char *buf, int *status, long *probed, + long *updated, char **text) +{ + char *probed_text; + char *updated_text; + + if ((probed_text = split_at(buf, ':')) != 0 + && (updated_text = split_at(probed_text, ':')) != 0 + && (*text = split_at(updated_text, ':')) != 0 + && alldig(buf) + && alldig(probed_text) + && alldig(updated_text)) { + *probed = atol(probed_text); + *updated = atol(updated_text); + *status = atoi(buf); + + /* + * Coverity 200604: the code incorrectly tested (probed || updated), + * so that the sanity check never detected all-zero time stamps. Such + * records are never written. If we read a record with all-zero time + * stamps, then something is badly broken. + */ + if ((*status == DEL_RCPT_STAT_OK + || *status == DEL_RCPT_STAT_DEFER + || *status == DEL_RCPT_STAT_BOUNCE + || *status == DEL_RCPT_STAT_TODO) + && (*probed || *updated)) + return (0); + } + msg_warn("bad address verify table entry: %.100s", buf); + return (-1); +} + +/* verify_stat2name - status to name */ + +static const char *verify_stat2name(int addr_status) +{ + if (addr_status == DEL_RCPT_STAT_OK) + return ("deliverable"); + if (addr_status == DEL_RCPT_STAT_DEFER) + return ("undeliverable"); + if (addr_status == DEL_RCPT_STAT_BOUNCE) + return ("undeliverable"); + return (0); +} + +/* verify_update_service - update address service */ + +static void verify_update_service(VSTREAM *client_stream) +{ + VSTRING *buf = vstring_alloc(10); + VSTRING *addr = vstring_alloc(10); + int addr_status; + VSTRING *text = vstring_alloc(10); + const char *status_name; + const char *raw_data; + long probed; + long updated; + + if (attr_scan(client_stream, ATTR_FLAG_STRICT, + RECV_ATTR_STR(MAIL_ATTR_ADDR, addr), + RECV_ATTR_INT(MAIL_ATTR_ADDR_STATUS, &addr_status), + RECV_ATTR_STR(MAIL_ATTR_WHY, text), + ATTR_TYPE_END) == 3) { + /* FIX 200501 IPv6 patch did not neuter ":" in address literals. */ + translit(STR(addr), ":", "_"); + if ((status_name = verify_stat2name(addr_status)) == 0) { + msg_warn("bad recipient status %d for recipient %s", + addr_status, STR(addr)); + attr_print(client_stream, ATTR_FLAG_NONE, + SEND_ATTR_INT(MAIL_ATTR_STATUS, VRFY_STAT_BAD), + ATTR_TYPE_END); + } else { + + /* + * Robustness: don't allow a failed probe to clobber an OK + * address before it expires. The failed probe is ignored so that + * the address will be re-probed upon the next query. As long as + * some probes succeed the address will remain cached as OK. + */ + if (addr_status == DEL_RCPT_STAT_OK + || (raw_data = dict_cache_lookup(verify_map, STR(addr))) == 0 + || STATUS_FROM_RAW_ENTRY(raw_data) != DEL_RCPT_STAT_OK) { + probed = 0; + updated = (long) time((time_t *) 0); + printable(STR(text), '?'); + verify_make_entry(buf, addr_status, probed, updated, STR(text)); + if (msg_verbose) + msg_info("PUT %s status=%d probed=%ld updated=%ld text=%s", + STR(addr), addr_status, probed, updated, STR(text)); + dict_cache_update(verify_map, STR(addr), STR(buf)); + } + attr_print(client_stream, ATTR_FLAG_NONE, + SEND_ATTR_INT(MAIL_ATTR_STATUS, VRFY_STAT_OK), + ATTR_TYPE_END); + } + } + vstring_free(buf); + vstring_free(addr); + vstring_free(text); +} + +/* verify_post_mail_fclose_action - callback */ + +static void verify_post_mail_fclose_action(int unused_status, + void *unused_context) +{ + /* no code here, we just need to avoid blocking in post_mail_fclose() */ +} + +/* verify_post_mail_action - callback */ + +static void verify_post_mail_action(VSTREAM *stream, void *context) +{ + + /* + * Probe messages need no body content, because they are never delivered, + * deferred, or bounced. + */ + if (stream != 0) + post_mail_fclose_async(stream, verify_post_mail_fclose_action, context); +} + +/* verify_query_service - query address status */ + +static void verify_query_service(VSTREAM *client_stream) +{ + VSTRING *addr = vstring_alloc(10); + VSTRING *get_buf = 0; + VSTRING *put_buf = 0; + const char *raw_data; + int addr_status; + long probed; + long updated; + char *text; + + if (attr_scan(client_stream, ATTR_FLAG_STRICT, + RECV_ATTR_STR(MAIL_ATTR_ADDR, addr), + ATTR_TYPE_END) == 1) { + long now = (long) time((time_t *) 0); + + /* + * Produce a default record when no usable record exists. + * + * If negative caching is disabled, purge an expired record from the + * database. + * + * XXX Assume that a probe is lost if no response is received in 1000 + * seconds. If this number is too small the queue will slowly fill up + * with delayed probes. + * + * XXX Maintain a moving average for the probe turnaround time, and + * allow probe "retransmission" when a probe is outstanding for, say + * some minimal amount of time (1000 sec) plus several times the + * observed probe turnaround time. This causes probing to back off + * when the mail system becomes congested. + */ +#define POSITIVE_ENTRY_EXPIRED(addr_status, updated) \ + (addr_status == DEL_RCPT_STAT_OK && updated + var_verify_pos_exp < now) +#define NEGATIVE_ENTRY_EXPIRED(addr_status, updated) \ + (addr_status != DEL_RCPT_STAT_OK && updated + var_verify_neg_exp < now) +#define PROBE_TTL 1000 + + /* FIX 200501 IPv6 patch did not neuter ":" in address literals. */ + translit(STR(addr), ":", "_"); + if ((raw_data = dict_cache_lookup(verify_map, STR(addr))) == 0 /* not found */ + || ((get_buf = vstring_alloc(10)), + vstring_strcpy(get_buf, raw_data), /* malformed */ + verify_parse_entry(STR(get_buf), &addr_status, &probed, + &updated, &text) < 0) + || (now - probed > PROBE_TTL /* safe to probe */ + && (POSITIVE_ENTRY_EXPIRED(addr_status, updated) + || NEGATIVE_ENTRY_EXPIRED(addr_status, updated)))) { + addr_status = DEL_RCPT_STAT_TODO; + probed = 0; + updated = 0; + text = "Address verification in progress"; + if (raw_data != 0 && var_verify_neg_cache == 0) + dict_cache_delete(verify_map, STR(addr)); + } + if (msg_verbose) + msg_info("GOT %s status=%d probed=%ld updated=%ld text=%s", + STR(addr), addr_status, probed, updated, text); + + /* + * Respond to the client. + */ + attr_print(client_stream, ATTR_FLAG_NONE, + SEND_ATTR_INT(MAIL_ATTR_STATUS, VRFY_STAT_OK), + SEND_ATTR_INT(MAIL_ATTR_ADDR_STATUS, addr_status), + SEND_ATTR_STR(MAIL_ATTR_WHY, text), + ATTR_TYPE_END); + + /* + * Send a new probe when the information needs to be refreshed. + * + * XXX For an initial proof of concept implementation, use synchronous + * mail submission. This needs to be made async for high-volume + * sites, which makes it even more interesting to eliminate duplicate + * queries while a probe is being built. + * + * If negative caching is turned off, update the database only when + * refreshing an existing entry. + */ +#define POSITIVE_REFRESH_NEEDED(addr_status, updated) \ + (addr_status == DEL_RCPT_STAT_OK && updated + var_verify_pos_try < now) +#define NEGATIVE_REFRESH_NEEDED(addr_status, updated) \ + (addr_status != DEL_RCPT_STAT_OK && updated + var_verify_neg_try < now) + + if (now - probed > PROBE_TTL + && (POSITIVE_REFRESH_NEEDED(addr_status, updated) + || NEGATIVE_REFRESH_NEEDED(addr_status, updated))) { + if (msg_verbose) + msg_info("PROBE %s status=%d probed=%ld updated=%ld", + STR(addr), addr_status, now, updated); + post_mail_fopen_async(make_verify_sender_addr(), STR(addr), + MAIL_SRC_MASK_VERIFY, + DEL_REQ_FLAG_MTA_VRFY, + SMTPUTF8_FLAG_NONE, + (VSTRING *) 0, + verify_post_mail_action, + (void *) 0); + if (updated != 0 || var_verify_neg_cache != 0) { + put_buf = vstring_alloc(10); + verify_make_entry(put_buf, addr_status, now, updated, text); + if (msg_verbose) + msg_info("PUT %s status=%d probed=%ld updated=%ld text=%s", + STR(addr), addr_status, now, updated, text); + dict_cache_update(verify_map, STR(addr), STR(put_buf)); + } + } + } + vstring_free(addr); + if (get_buf) + vstring_free(get_buf); + if (put_buf) + vstring_free(put_buf); +} + +/* verify_cache_validator - cache cleanup validator */ + +static int verify_cache_validator(const char *addr, const char *raw_data, + void *context) +{ + VSTRING *get_buf = (VSTRING *) context; + int addr_status; + long probed; + long updated; + char *text; + long now = (long) event_time(); + +#define POS_OR_NEG_ENTRY_EXPIRED(stat, stamp) \ + (POSITIVE_ENTRY_EXPIRED((stat), (stamp)) \ + || NEGATIVE_ENTRY_EXPIRED((stat), (stamp))) + + vstring_strcpy(get_buf, raw_data); + return (verify_parse_entry(STR(get_buf), &addr_status, /* syntax OK */ + &probed, &updated, &text) == 0 + && (now - probed < PROBE_TTL /* probe in progress */ + || !POS_OR_NEG_ENTRY_EXPIRED(addr_status, updated))); +} + +/* verify_service - perform service for client */ + +static void verify_service(VSTREAM *client_stream, char *unused_service, + char **argv) +{ + VSTRING *request = vstring_alloc(10); + + /* + * Sanity check. This service takes no command-line arguments. + */ + if (argv[0]) + msg_fatal("unexpected command-line argument: %s", argv[0]); + + /* + * This routine runs whenever a client connects to the socket dedicated + * to the address verification service. All connection-management stuff + * is handled by the common code in multi_server.c. + */ + if (attr_scan(client_stream, + ATTR_FLAG_MORE | ATTR_FLAG_STRICT, + RECV_ATTR_STR(MAIL_ATTR_REQ, request), + ATTR_TYPE_END) == 1) { + if (STREQ(STR(request), VRFY_REQ_UPDATE)) { + verify_update_service(client_stream); + } else if (STREQ(STR(request), VRFY_REQ_QUERY)) { + verify_query_service(client_stream); + } else { + msg_warn("unrecognized request: \"%s\", ignored", STR(request)); + attr_print(client_stream, ATTR_FLAG_NONE, + SEND_ATTR_INT(MAIL_ATTR_STATUS, VRFY_STAT_BAD), + ATTR_TYPE_END); + } + } + vstream_fflush(client_stream); + vstring_free(request); +} + +/* verify_dump - dump some statistics */ + +static void verify_dump(char *unused_name, char **unused_argv) +{ + + /* + * Dump preliminary cache cleanup statistics when the process commits + * suicide while a cache cleanup run is in progress. We can't currently + * distinguish between "postfix reload" (we should restart) or "maximal + * idle time reached" (we could finish the cache cleanup first). + */ + dict_cache_close(verify_map); + verify_map = 0; +} + +/* post_jail_init - post-jail initialization */ + +static void post_jail_init(char *unused_name, char **unused_argv) +{ + + /* + * If the database is in volatile memory only, prevent automatic process + * suicide after a limited number of client requests or after a limited + * amount of idle time. + */ + if (*var_verify_map == 0) { + var_use_limit = 0; + var_idle_limit = 0; + } + + /* + * Start the cache cleanup thread. + */ + if (var_verify_scan_cache > 0) { + int cache_flags; + + cache_flags = DICT_CACHE_FLAG_STATISTICS; + if (msg_verbose) + cache_flags |= DICT_CACHE_FLAG_VERBOSE; + dict_cache_control(verify_map, + CA_DICT_CACHE_CTL_FLAGS(cache_flags), + CA_DICT_CACHE_CTL_INTERVAL(var_verify_scan_cache), + CA_DICT_CACHE_CTL_VALIDATOR(verify_cache_validator), + CA_DICT_CACHE_CTL_CONTEXT((void *) vstring_alloc(100)), + CA_DICT_CACHE_CTL_END); + } +} + +/* pre_jail_init - pre-jail initialization */ + +static void pre_jail_init(char *unused_name, char **unused_argv) +{ + mode_t saved_mask; + VSTRING *redirect; + + /* + * Never, ever, get killed by a master signal, as that would corrupt the + * database when we're in the middle of an update. + */ + setsid(); + + /* + * Security: don't create root-owned files that contain untrusted data. + * And don't create Postfix-owned files in root-owned directories, + * either. We want a correct relationship between (file/directory) + * ownership and (file/directory) content. + * + * XXX Non-root open can violate the principle of least surprise: Postfix + * can't open an *SQL config file for database read-write access, even + * though it can open that same control file for database read-only + * access. + * + * The solution is to query a map type and obtain its properties before + * opening it. A clean solution is to add a dict_info() API that is + * similar to dict_open() except it returns properties (dict flags) only. + * A pragmatic solution is to overload the existing API and have + * dict_open() return a dummy map when given a null map name. + * + * However, the proxymap daemon has been opening *SQL maps as non-root for + * years now without anyone complaining, let's not solve a problem that + * doesn't exist. + */ + SAVE_AND_SET_EUGID(var_owner_uid, var_owner_gid); + redirect = vstring_alloc(100); + + /* + * Keep state in persistent (external) or volatile (internal) map. + * + * Start the cache cleanup thread after permanently dropping privileges. + */ +#define VERIFY_DICT_OPEN_FLAGS (DICT_FLAG_DUP_REPLACE | DICT_FLAG_SYNC_UPDATE \ + | DICT_FLAG_OPEN_LOCK | DICT_FLAG_UTF8_REQUEST) + + saved_mask = umask(022); + verify_map = + dict_cache_open(*var_verify_map ? + data_redirect_map(redirect, var_verify_map) : + "internal:verify", + O_CREAT | O_RDWR, VERIFY_DICT_OPEN_FLAGS); + (void) umask(saved_mask); + + /* + * Clean up and restore privilege. + */ + vstring_free(redirect); + RESTORE_SAVED_EUGID(); +} + +/* post_accept_init - announce our protocol */ + +static void post_accept_init(VSTREAM *stream, char *unused_name, + char **unused_argv, HTABLE *unused_table) +{ + + /* + * Announce the protocol. + */ + attr_print(stream, ATTR_FLAG_NONE, + SEND_ATTR_STR(MAIL_ATTR_PROTO, MAIL_ATTR_PROTO_VERIFY), + ATTR_TYPE_END); + (void) vstream_fflush(stream); +} + +MAIL_VERSION_STAMP_DECLARE; + +/* main - pass control to the multi-threaded skeleton */ + +int main(int argc, char **argv) +{ + static const CONFIG_STR_TABLE str_table[] = { + VAR_VERIFY_MAP, DEF_VERIFY_MAP, &var_verify_map, 0, 0, + VAR_VERIFY_SENDER, DEF_VERIFY_SENDER, &var_verify_sender, 0, 0, + 0, + }; + static const CONFIG_TIME_TABLE time_table[] = { + VAR_VERIFY_POS_EXP, DEF_VERIFY_POS_EXP, &var_verify_pos_exp, 1, 0, + VAR_VERIFY_POS_TRY, DEF_VERIFY_POS_TRY, &var_verify_pos_try, 1, 0, + VAR_VERIFY_NEG_EXP, DEF_VERIFY_NEG_EXP, &var_verify_neg_exp, 1, 0, + VAR_VERIFY_NEG_TRY, DEF_VERIFY_NEG_TRY, &var_verify_neg_try, 1, 0, + VAR_VERIFY_SCAN_CACHE, DEF_VERIFY_SCAN_CACHE, &var_verify_scan_cache, 0, 0, + VAR_VERIFY_SENDER_TTL, DEF_VERIFY_SENDER_TTL, &var_verify_sender_ttl, 0, 0, + 0, + }; + + /* + * Fingerprint executables and core dumps. + */ + MAIL_VERSION_STAMP_ALLOCATE; + + multi_server_main(argc, argv, verify_service, + CA_MAIL_SERVER_STR_TABLE(str_table), + CA_MAIL_SERVER_TIME_TABLE(time_table), + CA_MAIL_SERVER_PRE_INIT(pre_jail_init), + CA_MAIL_SERVER_POST_INIT(post_jail_init), + CA_MAIL_SERVER_POST_ACCEPT(post_accept_init), + CA_MAIL_SERVER_SOLITARY, + CA_MAIL_SERVER_EXIT(verify_dump), + 0); +} |