| 1 | /************************************************* |
| 2 | * Exim - an Internet mail transport agent * |
| 3 | *************************************************/ |
| 4 | |
| 5 | /* Copyright (c) Heiko Schlittermann 2016 |
| 6 | * hs@schlittermann.de |
| 7 | * See the file NOTICE for conditions of use and distribution. |
| 8 | */ |
| 9 | |
| 10 | #include "exim.h" |
| 11 | |
| 12 | extern char **environ; |
| 13 | |
| 14 | /* The cleanup_environment() function is used during the startup phase |
| 15 | of the Exim process, right after reading the configurations main |
| 16 | part, before any expansions take place. It retains the environment |
| 17 | variables we trust (via the keep_environment option) and allows to |
| 18 | set additional variables (via add_environment). |
| 19 | |
| 20 | Returns: TRUE if successful |
| 21 | FALSE otherwise |
| 22 | */ |
| 23 | |
| 24 | BOOL |
| 25 | cleanup_environment() |
| 26 | { |
| 27 | if (!keep_environment || *keep_environment == '\0') |
| 28 | { |
| 29 | /* From: https://github.com/dovecot/core/blob/master/src/lib/env-util.c#L55 |
| 30 | Try to clear the environment. |
| 31 | a) environ = NULL crashes on OS X. |
| 32 | b) *environ = NULL doesn't work on FreeBSD 7.0. |
| 33 | c) environ = emptyenv doesn't work on Haiku OS |
| 34 | d) environ = calloc() should work everywhere */ |
| 35 | |
| 36 | if (environ) *environ = NULL; |
| 37 | |
| 38 | } |
| 39 | else if (Ustrcmp(keep_environment, "*") != 0) |
| 40 | if (environ) for (uschar ** p = USS environ; *p; /* see below */) |
| 41 | { |
| 42 | /* It's considered broken if we do not find the '=', according to |
| 43 | Florian Weimer. For now we ignore such strings. unsetenv() would complain, |
| 44 | getenv() would complain. */ |
| 45 | uschar * eqp = Ustrchr(*p, '='); |
| 46 | |
| 47 | if (eqp) |
| 48 | { |
| 49 | uschar * name = string_copyn(*p, eqp - *p); |
| 50 | |
| 51 | if (OK != match_isinlist(name, CUSS &keep_environment, |
| 52 | 0, NULL, NULL, MCL_NOEXPAND, FALSE, NULL)) |
| 53 | if (os_unsetenv(name) < 0) return FALSE; |
| 54 | else p = USS environ; /* RESTART from the beginning */ |
| 55 | else p++; |
| 56 | store_reset(name); |
| 57 | } |
| 58 | } |
| 59 | if (add_environment) |
| 60 | { |
| 61 | uschar * p; |
| 62 | int sep = 0; |
| 63 | const uschar * envlist = add_environment; |
| 64 | |
| 65 | while ((p = string_nextinlist(&envlist, &sep, NULL, 0))) putenv(CS p); |
| 66 | } |
| 67 | |
| 68 | return TRUE; |
| 69 | } |