X-Git-Url: https://git.exim.org/users/jgh/exim.git/blobdiff_plain/273f34d076393a3df1b85a93f10d16f1a68f66a1..b7487bcec431809cb7fc3c2b42fcd607e43d37e7:/src/src/exim.c diff --git a/src/src/exim.c b/src/src/exim.c index 6f80dd131..e23697506 100644 --- a/src/src/exim.c +++ b/src/src/exim.c @@ -1,10 +1,10 @@ -/* $Cambridge: exim/src/src/exim.c,v 1.54 2007/01/25 15:51:28 ph10 Exp $ */ +/* $Cambridge: exim/src/src/exim.c,v 1.71 2010/06/07 00:12:42 pdp Exp $ */ /************************************************* * Exim - an Internet mail transport agent * *************************************************/ -/* Copyright (c) University of Cambridge 1995 - 2007 */ +/* Copyright (c) University of Cambridge 1995 - 2009 */ /* See the file NOTICE for conditions of use and distribution. */ @@ -14,6 +14,8 @@ Also a few functions that don't naturally fit elsewhere. */ #include "exim.h" +extern void init_lookup_list(void); + /************************************************* @@ -681,161 +683,12 @@ else -/************************************************* -* Decode bit settings for log/debug * -*************************************************/ - -/* This function decodes a string containing bit settings in the form of +name -and/or -name sequences, and sets/unsets bits in a bit string accordingly. It -also recognizes a numeric setting of the form =, but this is not -intended for user use. It's an easy way for Exim to pass the debug settings -when it is re-exec'ed. - -The log options are held in two unsigned ints (because there became too many -for one). The top bit in the table means "put in 2nd selector". This does not -yet apply to debug options, so the "=" facility sets only the first selector. - -The "all" selector, which must be equal to 0xffffffff, is recognized specially. -It sets all the bits in both selectors. However, there is a facility for then -unsetting certain bits, because we want to turn off "memory" in the debug case. - -A bad value for a debug setting is treated as an unknown option - error message -to stderr and die. For log settings, which come from the configuration file, -we write to the log on the way out... - -Arguments: - selector1 address of the first bit string - selector2 address of the second bit string, or NULL - notall1 bits to exclude from "all" for selector1 - notall2 bits to exclude from "all" for selector2 - string the configured string - options the table of option names - count size of table - which "log" or "debug" - -Returns: nothing on success - bomb out on failure -*/ - -static void -decode_bits(unsigned int *selector1, unsigned int *selector2, int notall1, - int notall2, uschar *string, bit_table *options, int count, uschar *which) -{ -uschar *errmsg; -if (string == NULL) return; - -if (*string == '=') - { - char *end; /* Not uschar */ - *selector1 = strtoul(CS string+1, &end, 0); - if (*end == 0) return; - errmsg = string_sprintf("malformed numeric %s_selector setting: %s", which, - string); - goto ERROR_RETURN; - } - -/* Handle symbolic setting */ - -else for(;;) - { - BOOL adding; - uschar *s; - int len; - bit_table *start, *end; - - while (isspace(*string)) string++; - if (*string == 0) return; - - if (*string != '+' && *string != '-') - { - errmsg = string_sprintf("malformed %s_selector setting: " - "+ or - expected but found \"%s\"", which, string); - goto ERROR_RETURN; - } - - adding = *string++ == '+'; - s = string; - while (isalnum(*string) || *string == '_') string++; - len = string - s; - - start = options; - end = options + count; - - while (start < end) - { - bit_table *middle = start + (end - start)/2; - int c = Ustrncmp(s, middle->name, len); - if (c == 0) - { - if (middle->name[len] != 0) c = -1; else - { - unsigned int bit = middle->bit; - unsigned int *selector; - - /* The value with all bits set means "force all bits in both selectors" - in the case where two are being handled. However, the top bit in the - second selector is never set. When setting, some bits can be excluded. - */ - - if (bit == 0xffffffff) - { - if (adding) - { - *selector1 = 0xffffffff ^ notall1; - if (selector2 != NULL) *selector2 = 0x7fffffff ^ notall2; - } - else - { - *selector1 = 0; - if (selector2 != NULL) *selector2 = 0; - } - } - - /* Otherwise, the 0x80000000 bit means "this value, without the top - bit, belongs in the second selector". */ - - else - { - if ((bit & 0x80000000) != 0) - { - selector = selector2; - bit &= 0x7fffffff; - } - else selector = selector1; - if (adding) *selector |= bit; else *selector &= ~bit; - } - break; /* Out of loop to match selector name */ - } - } - if (c < 0) end = middle; else start = middle + 1; - } /* Loop to match selector name */ - - if (start >= end) - { - errmsg = string_sprintf("unknown %s_selector setting: %c%.*s", which, - adding? '+' : '-', len, s); - goto ERROR_RETURN; - } - } /* Loop for selector names */ - -/* Handle disasters */ - -ERROR_RETURN: -if (Ustrcmp(which, "debug") == 0) - { - fprintf(stderr, "exim: %s\n", errmsg); - exit(EXIT_FAILURE); - } -else log_write(0, LOG_CONFIG|LOG_PANIC_DIE, "%s", errmsg); -} - - - /************************************************* * Show supported features * *************************************************/ -/* This function is called for -bV and for -d to output the optional features -of the current Exim binary. +/* This function is called for -bV/--version and for -d to output the optional +features of the current Exim binary. Arguments: a FILE for printing Returns: nothing @@ -905,6 +758,9 @@ fprintf(f, "Support for:"); #ifdef WITH_CONTENT_SCAN fprintf(f, " Content_Scanning"); #endif +#ifndef DISABLE_DKIM + fprintf(f, " DKIM"); +#endif #ifdef WITH_OLD_DEMIME fprintf(f, " Old_Demime"); #endif @@ -917,58 +773,58 @@ fprintf(f, "Support for:"); #ifdef EXPERIMENTAL_BRIGHTMAIL fprintf(f, " Experimental_Brightmail"); #endif -#ifdef EXPERIMENTAL_DOMAINKEYS - fprintf(f, " Experimental_DomainKeys"); +#ifdef EXPERIMENTAL_DCC + fprintf(f, " Experimental_DCC"); #endif fprintf(f, "\n"); -fprintf(f, "Lookups:"); -#ifdef LOOKUP_LSEARCH +fprintf(f, "Lookups (built-in):"); +#if defined(LOOKUP_LSEARCH) && LOOKUP_LSEARCH!=2 fprintf(f, " lsearch wildlsearch nwildlsearch iplsearch"); #endif -#ifdef LOOKUP_CDB +#if defined(LOOKUP_CDB) && LOOKUP_CDB!=2 fprintf(f, " cdb"); #endif -#ifdef LOOKUP_DBM +#if defined(LOOKUP_DBM) && LOOKUP_DBM!=2 fprintf(f, " dbm dbmnz"); #endif -#ifdef LOOKUP_DNSDB +#if defined(LOOKUP_DNSDB) && LOOKUP_DNSDB!=2 fprintf(f, " dnsdb"); #endif -#ifdef LOOKUP_DSEARCH +#if defined(LOOKUP_DSEARCH) && LOOKUP_DSEARCH!=2 fprintf(f, " dsearch"); #endif -#ifdef LOOKUP_IBASE +#if defined(LOOKUP_IBASE) && LOOKUP_IBASE!=2 fprintf(f, " ibase"); #endif -#ifdef LOOKUP_LDAP +#if defined(LOOKUP_LDAP) && LOOKUP_LDAP!=2 fprintf(f, " ldap ldapdn ldapm"); #endif -#ifdef LOOKUP_MYSQL +#if defined(LOOKUP_MYSQL) && LOOKUP_MYSQL!=2 fprintf(f, " mysql"); #endif -#ifdef LOOKUP_NIS +#if defined(LOOKUP_NIS) && LOOKUP_NIS!=2 fprintf(f, " nis nis0"); #endif -#ifdef LOOKUP_NISPLUS +#if defined(LOOKUP_NISPLUS) && LOOKUP_NISPLUS!=2 fprintf(f, " nisplus"); #endif -#ifdef LOOKUP_ORACLE +#if defined(LOOKUP_ORACLE) && LOOKUP_ORACLE!=2 fprintf(f, " oracle"); #endif -#ifdef LOOKUP_PASSWD +#if defined(LOOKUP_PASSWD) && LOOKUP_PASSWD!=2 fprintf(f, " passwd"); #endif -#ifdef LOOKUP_PGSQL +#if defined(LOOKUP_PGSQL) && LOOKUP_PGSQL!=2 fprintf(f, " pgsql"); #endif -#ifdef LOOKUP_SQLITE +#if defined(LOOKUP_SQLITE) && LOOKUP_SQLITE!=2 fprintf(f, " sqlite"); #endif -#ifdef LOOKUP_TESTDB +#if defined(LOOKUP_TESTDB) && LOOKUP_TESTDB!=2 fprintf(f, " testdb"); #endif -#ifdef LOOKUP_WHOSON +#if defined(LOOKUP_WHOSON) && LOOKUP_WHOSON!=2 fprintf(f, " whoson"); #endif fprintf(f, "\n"); @@ -1051,7 +907,53 @@ if (fixed_never_users[0] > 0) fprintf(f, "%d\n", (unsigned int)fixed_never_users[i]); } -fprintf(f, "Size of off_t: %d\n", sizeof(off_t)); +fprintf(f, "Size of off_t: " SIZE_T_FMT "\n", sizeof(off_t)); + +/* This runtime check is to help diagnose library linkage mismatches which +result in segfaults and the like; as such, it's left until the end, +just in case. There will still be a "Configuration file is" line still to +come. */ +#ifdef SUPPORT_TLS +tls_version_report(f); +#endif + +/* Everything else is details which are only worth reporting when debugging. +Perhaps the tls_version_report should move into this too. */ +DEBUG(D_any) do { + + int i; + +#ifdef AUTH_CYRUS_SASL + auth_cyrus_sasl_version_report(f); +#endif + + fprintf(f, "Library version: PCRE: Compile: %d.%d%s\n" + " Runtime: %s\n", + PCRE_MAJOR, PCRE_MINOR, + /* PRE_PRERELEASE is either defined and empty or a string. + * This should work: */ + PCRE_PRERELEASE "", + pcre_version()); + + init_lookup_list(); + for (i = 0; i < lookup_list_count; i++) + { + if (lookup_list[i]->version_report) + lookup_list[i]->version_report(f); + } + +#ifdef WHITELIST_D_MACROS + fprintf(f, "WHITELIST_D_MACROS: \"%s\"\n", WHITELIST_D_MACROS); +#else + fprintf(f, "WHITELIST_D_MACROS unset\n"); +#endif +#ifdef TRUSTED_CONFIG_LIST + fprintf(f, "TRUSTED_CONFIG_LIST: \"%s\"\n", TRUSTED_CONFIG_LIST); +#else + fprintf(f, "TRUSTED_CONFIG_LIST unset\n"); +#endif + +} while (0); } @@ -1232,6 +1134,154 @@ return yield; +/************************************************* +* Output usage information for the program * +*************************************************/ + +/* This function is called when there are no recipients + or a specific --help argument was added. + +Arguments: + progname information on what name we were called by + +Returns: DOES NOT RETURN +*/ + +static void +exim_usage(uschar *progname) +{ + +/* Handle specific program invocation varients */ +if (Ustrcmp(progname, US"-mailq") == 0) + { + fprintf(stderr, + "mailq - list the contents of the mail queue\n\n" + "For a list of options, see the Exim documentation.\n"); + exit(EXIT_FAILURE); + } + +/* Generic usage - we output this whatever happens */ +fprintf(stderr, + "Exim is a Mail Transfer Agent. It is normally called by Mail User Agents,\n" + "not directly from a shell command line. Options and/or arguments control\n" + "what it does when called. For a list of options, see the Exim documentation.\n"); + +exit(EXIT_FAILURE); +} + + + +/************************************************* +* Validate that the macros given are okay * +*************************************************/ + +/* Typically, Exim will drop privileges if macros are supplied. In some +cases, we want to not do so. + +Arguments: none (macros is a global) +Returns: true if trusted, false otherwise +*/ + +static BOOL +macros_trusted(void) +{ +#ifdef WHITELIST_D_MACROS +macro_item *m; +uschar *whitelisted, *end, *p, **whites, **w; +int white_count, i, n; +size_t len; +BOOL prev_char_item, found; +#endif + +if (macros == NULL) + return TRUE; +#ifndef WHITELIST_D_MACROS +return FALSE; +#else + +/* We only trust -D overrides for some invoking users: +root, the exim run-time user, the optional config owner user. +I don't know why config-owner would be needed, but since they can own the +config files anyway, there's no security risk to letting them override -D. */ +if ( ! ((real_uid == root_uid) + || (real_uid == exim_uid) +#ifdef CONFIGURE_OWNER + || (real_uid == config_uid) +#endif + )) + { + debug_printf("macros_trusted rejecting macros for uid %d\n", (int) real_uid); + return FALSE; + } + +/* Get a list of macros which are whitelisted */ +whitelisted = string_copy_malloc(US WHITELIST_D_MACROS); +prev_char_item = FALSE; +white_count = 0; +for (p = whitelisted; *p != '\0'; ++p) + { + if (*p == ':' || isspace(*p)) + { + *p = '\0'; + if (prev_char_item) + ++white_count; + prev_char_item = FALSE; + continue; + } + if (!prev_char_item) + prev_char_item = TRUE; + } +end = p; +if (prev_char_item) + ++white_count; +if (!white_count) + return FALSE; +whites = store_malloc(sizeof(uschar *) * (white_count+1)); +for (p = whitelisted, i = 0; (p != end) && (i < white_count); ++p) + { + if (*p != '\0') + { + whites[i++] = p; + if (i == white_count) + break; + while (*p != '\0' && p < end) + ++p; + } + } +whites[i] = NULL; + +/* The list of macros should be very short. Accept the N*M complexity. */ +for (m = macros; m != NULL; m = m->next) + { + found = FALSE; + for (w = whites; *w; ++w) + if (Ustrcmp(*w, m->name) == 0) + { + found = TRUE; + break; + } + if (!found) + return FALSE; + if (m->replacement == NULL) + continue; + len = Ustrlen(m->replacement); + if (len == 0) + continue; + n = pcre_exec(regex_whitelisted_macro, NULL, CS m->replacement, len, + 0, PCRE_EOPT, NULL, 0); + if (n < 0) + { + if (n != PCRE_ERROR_NOMATCH) + debug_printf("macros_trusted checking %s returned %d\n", m->name, n); + return FALSE; + } + } +debug_printf("macros_trusted overriden to true by whitelisting\n"); +return TRUE; +#endif +} + + /************************************************* * Entry point and high-level code * *************************************************/ @@ -1261,7 +1311,7 @@ int arg_error_handling = error_handling; int filter_sfd = -1; int filter_ufd = -1; int group_count; -int i; +int i, rv; int list_queue_option = 0; int msg_action = 0; int msg_action_arg = -1; @@ -1291,8 +1341,10 @@ BOOL one_msg_action = FALSE; BOOL queue_only_set = FALSE; BOOL receiving_message = TRUE; BOOL sender_ident_set = FALSE; +BOOL session_local_queue_only; BOOL unprivileged; BOOL removed_privilege = FALSE; +BOOL usage_wanted = FALSE; BOOL verify_address_mode = FALSE; BOOL verify_as_sender = FALSE; BOOL version_printed = FALSE; @@ -1305,6 +1357,7 @@ uschar *ftest_domain = NULL; uschar *ftest_localpart = NULL; uschar *ftest_prefix = NULL; uschar *ftest_suffix = NULL; +uschar *malware_test_file = NULL; uschar *real_sender_address; uschar *originator_home = US"/"; void *reset_point; @@ -1332,6 +1385,12 @@ This is a feature to make the lives of binary distributors easier. */ #ifdef EXIM_USERNAME if (route_finduser(US EXIM_USERNAME, &pw, &exim_uid)) { + if (exim_uid == 0) + { + fprintf(stderr, "exim: refusing to run with uid 0 for \"%s\"\n", + EXIM_USERNAME); + exit(EXIT_FAILURE); + } exim_gid = pw->pw_gid; } else @@ -1360,6 +1419,10 @@ if (!route_finduser(US CONFIGURE_OWNERNAME, NULL, &config_uid)) } #endif +/* We default the system_filter_user to be the Exim run-time user, as a +sane non-root value. */ +system_filter_uid = exim_uid; + #ifdef CONFIGURE_GROUPNAME if (!route_findgroup(US CONFIGURE_GROUPNAME, &config_gid)) { @@ -1505,6 +1568,15 @@ regex_smtp_code = regex_must_compile(US"^\\d\\d\\d\\s(?:\\d\\.\\d\\d?\\d?\\.\\d\\d?\\d?\\s)?", FALSE, TRUE); +#ifdef WHITELIST_D_MACROS +/* Precompile the regular expression used to filter the content of macros +given to -D for permissibility. */ + +regex_whitelisted_macro = + regex_must_compile(US"^[A-Za-z0-9_/.-]*$", FALSE, TRUE); +#endif + + /* If the program is called as "mailq" treat it as equivalent to "exim -bp"; this seems to be a generally accepted convention, since one finds symbolic links called "mailq" in standard OS configurations. */ @@ -1578,8 +1650,20 @@ real_gid = getgid(); if (real_uid == root_uid) { - setgid(real_gid); - setuid(real_uid); + rv = setgid(real_gid); + if (rv) + { + fprintf(stderr, "exim: setgid(%ld) failed: %s\n", + (long int)real_gid, strerror(errno)); + exit(EXIT_FAILURE); + } + rv = setuid(real_uid); + if (rv) + { + fprintf(stderr, "exim: setuid(%ld) failed: %s\n", + (long int)real_uid, strerror(errno)); + exit(EXIT_FAILURE); + } } /* If neither the original real uid nor the original euid was root, Exim is @@ -1587,11 +1671,6 @@ running in an unprivileged state. */ unprivileged = (real_uid != root_uid && original_euid != root_uid); -/* If the first argument is --help, pretend there are no arguments. This will -cause a brief message to be given. */ - -if (argc > 1 && Ustrcmp(argv[1], "--help") == 0) argc = 1; - /* Scan the program's arguments. Some can be dealt with right away; others are simply recorded for checking and handling afterwards. Do a high-level switch on the second character (the one after '-'), to save some effort. */ @@ -1656,6 +1735,21 @@ for (i = 1; i < argc; i++) argrest++; } + /* deal with --option_aliases */ + else if (switchchar == '-') + { + if (Ustrcmp(argrest, "help") == 0) + { + usage_wanted = TRUE; + break; + } + else if (Ustrcmp(argrest, "version") == 0) + { + switchchar = 'b'; + argrest = US"V"; + } + } + /* High-level switch on active initial letter */ switch(switchchar) @@ -1766,6 +1860,14 @@ for (i = 1; i < argc; i++) else if (Ustrcmp(argrest, "m") == 0) receiving_message = TRUE; + /* -bmalware: test the filename given for malware */ + + else if (Ustrcmp(argrest, "malware") == 0) + { + if (++i >= argc) { badarg = TRUE; break; } + malware_test_file = argv[i]; + } + /* -bnq: For locally originating messages, do not qualify unqualified addresses. In the envelope, this causes errors; in header lines they just get left. */ @@ -1919,6 +2021,103 @@ for (i = 1; i < argc; i++) } } #endif + if (real_uid != root_uid) + { + #ifdef TRUSTED_CONFIG_LIST + + if (real_uid != exim_uid + #ifdef CONFIGURE_OWNER + && real_uid != config_uid + #endif + ) + trusted_config = FALSE; + else + { + FILE *trust_list = Ufopen(TRUSTED_CONFIG_LIST, "rb"); + if (trust_list) + { + struct stat statbuf; + + if (fstat(fileno(trust_list), &statbuf) != 0 || + (statbuf.st_uid != root_uid /* owner not root */ + #ifdef CONFIGURE_OWNER + && statbuf.st_uid != config_uid /* owner not the special one */ + #endif + ) || /* or */ + (statbuf.st_gid != root_gid /* group not root */ + #ifdef CONFIGURE_GROUP + && statbuf.st_gid != config_gid /* group not the special one */ + #endif + && (statbuf.st_mode & 020) != 0 /* group writeable */ + ) || /* or */ + (statbuf.st_mode & 2) != 0) /* world writeable */ + { + trusted_config = FALSE; + fclose(trust_list); + } + else + { + /* Well, the trust list at least is up to scratch... */ + void *reset_point = store_get(0); + uschar *trusted_configs[32]; + int nr_configs = 0; + int i = 0; + + while (Ufgets(big_buffer, big_buffer_size, trust_list)) + { + uschar *start = big_buffer, *nl; + while (*start && isspace(*start)) + start++; + if (*start != '/') + continue; + nl = Ustrchr(start, '\n'); + if (nl) + *nl = 0; + trusted_configs[nr_configs++] = string_copy(start); + if (nr_configs == 32) + break; + } + fclose(trust_list); + + if (nr_configs) + { + int sep = 0; + uschar *list = argrest; + uschar *filename; + while (trusted_config && (filename = string_nextinlist(&list, + &sep, big_buffer, big_buffer_size)) != NULL) + { + for (i=0; i < nr_configs; i++) + { + if (Ustrcmp(filename, trusted_configs[i]) == 0) + break; + } + if (i == nr_configs) + { + trusted_config = FALSE; + break; + } + } + store_reset(reset_point); + } + else + { + /* No valid prefixes found in trust_list file. */ + trusted_config = FALSE; + } + } + } + else + { + /* Could not open trust_list file. */ + trusted_config = FALSE; + } + } + #else + /* Not root; don't trust config */ + trusted_config = FALSE; + #endif + } config_main_filelist = argrest; config_changed = TRUE; @@ -2016,7 +2215,7 @@ for (i = 1; i < argc; i++) } if (*argrest != 0) decode_bits(&selector, NULL, D_memory, 0, argrest, debug_options, - debug_options_count, US"debug"); + debug_options_count, US"debug", 0); debug_selector = selector; } break; @@ -2165,6 +2364,9 @@ for (i = 1; i < argc; i++) if (Ustrcmp(argrest, "C") == 0) { + union sockaddr_46 interface_sock; + EXIM_SOCKLEN_T size = sizeof(interface_sock); + if (argc != i + 6) { fprintf(stderr, "exim: too many or too few arguments after -MC\n"); @@ -2194,6 +2396,19 @@ for (i = 1; i < argc; i++) return EXIT_FAILURE; } + /* Set up $sending_ip_address and $sending_port */ + + if (getsockname(fileno(stdin), (struct sockaddr *)(&interface_sock), + &size) == 0) + sending_ip_address = host_ntoa(-1, &interface_sock, NULL, + &sending_port); + else + { + fprintf(stderr, "exim: getsockname() failed after -MC option: %s\n", + strerror(errno)); + return EXIT_FAILURE; + } + if (running_in_test_harness) millisleep(500); break; } @@ -2267,6 +2482,7 @@ for (i = 1; i < argc; i++) -Mes edit sender -Mset load a message for use with -be -Mvb show body + -Mvc show copy (of whole message, in RFC 2822 format) -Mvh show header -Mvl show log */ @@ -2314,6 +2530,11 @@ for (i = 1; i < argc; i++) msg_action = MSG_SHOW_BODY; one_msg_action = TRUE; } + else if (Ustrcmp(argrest, "vc") == 0) + { + msg_action = MSG_SHOW_COPY; + one_msg_action = TRUE; + } else if (Ustrcmp(argrest, "vh") == 0) { msg_action = MSG_SHOW_HEADER; @@ -2903,9 +3124,11 @@ if ((deliver_selectstring != NULL || deliver_selectstring_sender != NULL) && queue_interval < 0) queue_interval = 0; -/* Arguments have been processed. Check for incompatibilities. */ - END_ARG: +/* If usage_wanted is set we call the usage function - which never returns */ +if (usage_wanted) exim_usage(called_as); + +/* Arguments have been processed. Check for incompatibilities. */ if (( (smtp_input || extract_recipients || recipients_arg < argc) && (daemon_listen || queue_interval >= 0 || bi_option || @@ -2972,7 +3195,8 @@ if (debug_selector != 0) debug_printf("Exim version %s uid=%ld gid=%ld pid=%d D=%x\n", version_string, (long int)real_uid, (long int)real_gid, (int)getpid(), debug_selector); - show_whats_supported(stderr); + if (!version_printed) + show_whats_supported(stderr); } } @@ -3080,11 +3304,11 @@ if (setgroups(0, NULL) != 0) /* If the configuration file name has been altered by an argument on the command line (either a new file name or a macro definition) and the caller is -not root or the exim user, or if this is a filter testing run, remove any -setuid privilege the program has, and run as the underlying user. +not root, or if this is a filter testing run, remove any setuid privilege the +program has and run as the underlying user. -If ALT_CONFIG_ROOT_ONLY is defined, the exim user is locked out of this, which -severely restricts the use of -C for some purposes. +The exim user is locked out of this, which severely restricts the use of -C +for some purposes. Otherwise, set the real ids to the effective values (should be root unless run from inetd, which it can either be root or the exim uid, if one is configured). @@ -3096,11 +3320,9 @@ values (such as the path name). If running in the test harness, pretend that configuration file changes and macro definitions haven't happened. */ if (( /* EITHER */ - (config_changed || macros != NULL) && /* Config changed, and */ + (!trusted_config || /* Config changed, or */ + !macros_trusted()) && /* impermissible macros and */ real_uid != root_uid && /* Not root, and */ - #ifndef ALT_CONFIG_ROOT_ONLY /* (when not locked out) */ - real_uid != exim_uid && /* Not exim, and */ - #endif !running_in_test_harness /* Not fudged */ ) || /* OR */ expansion_test /* expansion testing */ @@ -3116,9 +3338,13 @@ if (( /* EITHER */ and should be used for any logging information because attempts to write to the log will usually fail. To arrange this, we unset really_exim. However, if no stderr is available there is no point - we might as well have a go - at the log (if it fails, syslog will be written). */ + at the log (if it fails, syslog will be written). + + Note that if the invoker is Exim, the logs remain available. Messing with + this causes unlogged successful deliveries. */ - if (log_stderr != NULL) really_exim = FALSE; + if ((log_stderr != NULL) && (real_uid != exim_uid)) + really_exim = FALSE; } /* Privilege is to be retained for the moment. It may be dropped later, @@ -3161,8 +3387,8 @@ readconf_main(); /* Handle the decoding of logging options. */ -decode_bits(&log_write_selector, &log_extra_selector, 0, 0, log_selector_string, - log_options, log_options_count, US"log"); +decode_bits(&log_write_selector, &log_extra_selector, 0, 0, + log_selector_string, log_options, log_options_count, US"log", 0); DEBUG(D_any) { @@ -3288,15 +3514,12 @@ else } /* Handle the case when we have removed the setuid privilege because of -C or --D. This means that the caller of Exim was not root, and, provided that -ALT_CONFIG_ROOT_ONLY is not defined, was not the Exim user that is built into -the binary. +-D. This means that the caller of Exim was not root. -If ALT_CONFIG_ROOT_ONLY is not defined, there is a problem if it turns out we -were running as the exim user defined in the configuration file (different to -the one in the binary). The sysadmin may expect this case to retain privilege -because "the binary was called by the Exim user", but it hasn't, because of the -order in which it handles this stuff. There are two possibilities: +There is a problem if we were running as the Exim user. The sysadmin may +expect this case to retain privilege because "the binary was called by the +Exim user", but it hasn't, because either the -D option set macros, or the +-C option set a non-trusted configuration file. There are two possibilities: (1) If deliver_drop_privilege is set, Exim is not going to re-exec in order to do message deliveries. Thus, the fact that it is running as a @@ -3308,27 +3531,18 @@ order in which it handles this stuff. There are two possibilities: (2) If deliver_drop_privilege is not set, the configuration won't work as apparently intended, and so we log a panic message. In order to retain - root for -C or -D, the caller must either be root or the Exim user - defined in the binary (when deliver_drop_ privilege is false). + root for -C or -D, the caller must either be root or be invoking a + trusted configuration file (when deliver_drop_privilege is false). */ -If ALT_CONFIG_ROOT_ONLY is defined, we don't know whether we were called by the -built-in exim user or one defined in the configuration. In either event, -re-enable log processing, assuming the sysadmin knows what they are doing. */ - -if (removed_privilege && (config_changed || macros != NULL) && +if (removed_privilege && (!trusted_config || macros != NULL) && real_uid == exim_uid) { - #ifdef ALT_CONFIG_ROOT_ONLY - really_exim = TRUE; /* let logging work normally */ - #else - if (deliver_drop_privilege) really_exim = TRUE; /* let logging work normally */ else log_write(0, LOG_MAIN|LOG_PANIC, - "exim user (uid=%d) is defined only at runtime; privilege lost for %s", - (int)exim_uid, config_changed? "-C" : "-D"); - #endif + "exim user lost privilege for using %s option", + trusted_config? "-D" : "-C"); } /* Start up Perl interpreter if Perl support is configured and there is a @@ -3353,6 +3567,13 @@ if (opt_perl_at_start && opt_perl_startup != NULL) } #endif /* EXIM_PERL */ +/* Initialise lookup_list +If debugging, already called above via version reporting. +This does mean that debugging causes the list to be initialised while root. +This *should* be harmless -- all modules are loaded from a fixed dir and +it's code that would, if not a module, be part of Exim already. */ +init_lookup_list(); + /* Log the arguments of the call if the configuration file said so. This is a debugging feature for finding out what arguments certain MUAs actually use. Don't attempt it if logging is disabled, or if listing variables or if @@ -3458,7 +3679,6 @@ if (real_uid == root_uid || real_uid == exim_uid || real_gid == exim_gid) else { int i, j; - for (i = 0; i < group_count; i++) { if (group_list[i] == exim_gid) admin_user = TRUE; @@ -3514,12 +3734,13 @@ configuration, but the queue run restriction can be relaxed. Only an admin user may request that a message be returned to its sender forthwith. Only an admin user may specify a debug level greater than D_v (because it might show passwords, etc. in lookup queries). Only an admin user may request a queue -count. */ +count. Only an admin user can use the test interface to scan for email +(because Exim will be in the spool dir and able to look at mails). */ if (!admin_user) { BOOL debugset = (debug_selector & ~D_v) != 0; - if (deliver_give_up || daemon_listen || + if (deliver_give_up || daemon_listen || malware_test_file || (count_queue && queue_list_requires_admin) || (list_queue && queue_list_requires_admin) || (queue_interval >= 0 && prod_requires_admin) || @@ -3622,7 +3843,7 @@ if (receiving_message && (is_inetd && smtp_load_reserve >= 0) )) { - load_average = os_getloadavg(); + load_average = OS_GETLOADAVG(); } #endif @@ -3668,7 +3889,55 @@ if (!unprivileged && /* originally had root AND */ /* When we are retaining a privileged uid, we still change to the exim gid. */ -else setgid(exim_gid); +else + { + int rv; + rv = setgid(exim_gid); + /* Impact of failure is that some stuff might end up with an incorrect group. + We track this for failures from root, since any attempt to change privilege + by root should succeed and failures should be examined. For non-root, + there's no security risk. For me, it's { exim -bV } on a just-built binary, + no need to complain then. */ + if (rv == -1) + { + if (!(unprivileged || removed_privilege)) + { + fprintf(stderr, + "exim: changing group failed: %s\n", strerror(errno)); + exit(EXIT_FAILURE); + } + else + DEBUG(D_any) debug_printf("changing group to %ld failed: %s\n", + (long int)exim_gid, strerror(errno)); + } + } + +/* Handle a request to scan a file for malware */ +if (malware_test_file) + { +#ifdef WITH_CONTENT_SCAN + int result; + set_process_info("scanning file for malware"); + result = malware_in_file(malware_test_file); + if (result == FAIL) + { + printf("No malware found.\n"); + exit(EXIT_SUCCESS); + } + if (result != OK) + { + printf("Malware lookup returned non-okay/fail: %d\n", result); + exit(EXIT_FAILURE); + } + if (malware_name) + printf("Malware found: %s\n", malware_name); + else + printf("Malware scan detected malware of unknown name.\n"); +#else + printf("Malware scanning not enabled at compile time.\n"); +#endif + exit(EXIT_FAILURE); + } /* Handle a request to list the delivery queue */ @@ -3861,7 +4130,8 @@ if (list_options) if (i < argc - 1 && (Ustrcmp(argv[i], "router") == 0 || Ustrcmp(argv[i], "transport") == 0 || - Ustrcmp(argv[i], "authenticator") == 0)) + Ustrcmp(argv[i], "authenticator") == 0 || + Ustrcmp(argv[i], "macro") == 0)) { readconf_print(argv[i+1], argv[i]); i++; @@ -4402,14 +4672,9 @@ if (recipients_arg >= argc && !extract_recipients && !smtp_input) printf("Configuration file is %s\n", config_main_filename); return EXIT_SUCCESS; } + if (filter_test == FTEST_NONE) - { - fprintf(stderr, -"Exim is a Mail Transfer Agent. It is normally called by Mail User Agents,\n" -"not directly from a shell command line. Options and/or arguments control\n" -"what it does when called. For a list of options, see the Exim documentation.\n"); - return EXIT_FAILURE; - } + exim_usage(called_as); } @@ -4507,11 +4772,11 @@ else sender_address); } -/* Initialize the local_queue-only flag (this will be ignored if mua_wrapper is -set) */ +/* Initialize the session_local_queue-only flag (this will be ignored if +mua_wrapper is set) */ queue_check_only(); -local_queue_only = queue_only; +session_local_queue_only = queue_only; /* For non-SMTP and for batched SMTP input, check that there is enough space on the spool if so configured. On failure, we must not attempt to send an error @@ -4870,27 +5135,36 @@ while (more) } /* Else act on the result of message reception. We should not get here unless - message_id[0] is non-zero. If queue_only is set, local_queue_only will be - TRUE. If it is not, check on the number of messages received in this - connection. If that's OK and queue_only_load is set, check that the load - average is below it. If it is not, set local_queue_only TRUE. Note that it - then remains this way for any subsequent messages on the same SMTP connection. - This is a deliberate choice; even though the load average may fall, it - doesn't seem right to deliver later messages on the same call when not - delivering earlier ones. */ - - if (!local_queue_only) + message_id[0] is non-zero. If queue_only is set, session_local_queue_only + will be TRUE. If it is not, check on the number of messages received in this + connection. */ + + if (!session_local_queue_only && + smtp_accept_queue_per_connection > 0 && + receive_messagecount > smtp_accept_queue_per_connection) { - if (smtp_accept_queue_per_connection > 0 && - receive_messagecount > smtp_accept_queue_per_connection) - { - local_queue_only = TRUE; - queue_only_reason = 2; - } - else if (queue_only_load >= 0) + session_local_queue_only = TRUE; + queue_only_reason = 2; + } + + /* Initialize local_queue_only from session_local_queue_only. If it is false, + and queue_only_load is set, check that the load average is below it. If it is + not, set local_queue_only TRUE. If queue_only_load_latch is true (the + default), we put the whole session into queue_only mode. It then remains this + way for any subsequent messages on the same SMTP connection. This is a + deliberate choice; even though the load average may fall, it doesn't seem + right to deliver later messages on the same call when not delivering earlier + ones. However, there are odd cases where this is not wanted, so this can be + changed by setting queue_only_load_latch false. */ + + local_queue_only = session_local_queue_only; + if (!local_queue_only && queue_only_load >= 0) + { + local_queue_only = (load_average = OS_GETLOADAVG()) > queue_only_load; + if (local_queue_only) { - local_queue_only = (load_average = os_getloadavg()) > queue_only_load; - if (local_queue_only) queue_only_reason = 3; + queue_only_reason = 3; + if (queue_only_load_latch) session_local_queue_only = TRUE; } }