/*++ /* 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, char *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); } }