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Diffstat (limited to '')
| -rw-r--r-- | src/postscreen/postscreen_expand.c | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/src/postscreen/postscreen_expand.c b/src/postscreen/postscreen_expand.c new file mode 100644 index 0000000..ecda543 --- /dev/null +++ b/src/postscreen/postscreen_expand.c @@ -0,0 +1,141 @@ +/*++ +/* NAME +/* postscreen_expand 3 +/* SUMMARY +/* SMTP server macro expansion +/* SYNOPSIS +/* #include <postscreen.h> +/* +/* void psc_expand_init() +/* +/* VSTRING *psc_expand_filter; +/* +/* const char *psc_expand_lookup(name, unused_mode, context) +/* const char *name; +/* int unused_mode; +/* char *context; +/* DESCRIPTION +/* This module expands session-related macros. +/* +/* psc_expand_init() performs one-time initialization +/* of the psc_expand_filter buffer. +/* +/* The psc_expand_filter buffer contains the characters +/* that are allowed in macro expansion, as specified with the +/* psc_expand_filter configuration parameter. +/* +/* psc_expand_lookup() returns the value of the named +/* macro or a null pointer. +/* +/* Arguments: +/* .IP name +/* Macro name. +/* .IP context +/* Call-back context (a PSC_STATE pointer). +/* DIAGNOSTICS +/* Panic: interface violations. Fatal errors: out of memory. +/* internal protocol errors. postscreen_expand() returns the +/* binary OR of MAC_PARSE_ERROR (syntax error) and MAC_PARSE_UNDEF +/* (undefined macro name). +/* LICENSE +/* .ad +/* .fi +/* The Secure Mailer license must be distributed with this software. +/* AUTHOR(S) +/* Wietse Venema +/* IBM T.J. Watson Research +/* P.O. Box 704 +/* Yorktown Heights, NY 10598, USA +/*--*/ + +/* System library. */ + +#include <sys_defs.h> +#include <time.h> + +/* Utility library. */ + +#include <msg.h> +#include <vstring.h> +#include <stringops.h> + +/* Global library. */ + +#include <mail_params.h> +#include <mail_proto.h> + +/* Application-specific. */ + +#include <postscreen.h> + + /* + * Pre-parsed expansion filter. + */ +VSTRING *psc_expand_filter; + +/* psc_expand_init - initialize once during process lifetime */ + +void psc_expand_init(void) +{ + + /* + * Expand the expansion filter :-) + */ + psc_expand_filter = vstring_alloc(10); + unescape(psc_expand_filter, var_psc_exp_filter); +} + +/* psc_expand_lookup - generic SMTP attribute $name expansion */ + +const char *psc_expand_lookup(const char *name, int unused_mode, + void *context) +{ + PSC_STATE *state = (PSC_STATE *) context; + time_t now; + struct tm *lt; + + if (state->expand_buf == 0) + state->expand_buf = vstring_alloc(10); + + if (msg_verbose > 1) + msg_info("psc_expand_lookup: ${%s}", name); + +#define STREQ(x,y) (*(x) == *(y) && strcmp((x), (y)) == 0) +#define STREQN(x,y,n) (*(x) == *(y) && strncmp((x), (y), (n)) == 0) +#define CONST_LEN(x) (sizeof(x) - 1) + + /* + * Don't query main.cf parameters, as the result of expansion could + * reveal system-internal information in server replies. + * + * XXX: This said, multiple servers may be behind a single client-visible + * name or IP address, and each may generate its own logs. Therefore, it + * may be useful to expose the replying MTA id (myhostname) in the + * contact footer, to identify the right logs. So while we don't expose + * the raw configuration dictionary, we do expose "$myhostname" as + * expanded in var_myhostname. + * + * Return NULL only for non-existent names. + */ + if (STREQ(name, MAIL_ATTR_SERVER_NAME)) { + return (var_myhostname); + } else if (STREQ(name, MAIL_ATTR_ACT_CLIENT_ADDR)) { + return (state->smtp_client_addr); + } else if (STREQ(name, MAIL_ATTR_ACT_CLIENT_PORT)) { + return (state->smtp_client_port); + } if (STREQ(name, MAIL_ATTR_LOCALTIME)) { + if (time(&now) == (time_t) -1) + msg_fatal("time lookup failed: %m"); + lt = localtime(&now); + VSTRING_RESET(state->expand_buf); + do { + VSTRING_SPACE(state->expand_buf, 100); + } while (strftime(STR(state->expand_buf), + vstring_avail(state->expand_buf), + "%b %d %H:%M:%S", lt) == 0); + return (STR(state->expand_buf)); + } else { + msg_warn("unknown macro name \"%s\" in expansion request", name); + return (0); + } +} |