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Diffstat (limited to '')
| -rw-r--r-- | src/trivial-rewrite/rewrite.c | 303 |
1 files changed, 303 insertions, 0 deletions
diff --git a/src/trivial-rewrite/rewrite.c b/src/trivial-rewrite/rewrite.c new file mode 100644 index 0000000..483463c --- /dev/null +++ b/src/trivial-rewrite/rewrite.c @@ -0,0 +1,303 @@ +/*++ +/* NAME +/* rewrite 3 +/* SUMMARY +/* mail address rewriter +/* SYNOPSIS +/* #include "trivial-rewrite.h" +/* +/* void rewrite_init(void) +/* +/* void rewrite_proto(stream) +/* VSTREAM *stream; +/* +/* void rewrite_addr(context, addr, result) +/* RWR_CONTEXT *context; +/* char *addr; +/* VSTRING *result; +/* +/* void rewrite_tree(context, tree) +/* RWR_CONTEXT *context; +/* TOK822 *tree; +/* +/* RWR_CONTEXT local_context; +/* RWR_CONTEXT remote_context; +/* DESCRIPTION +/* This module implements the trivial address rewriting engine. +/* +/* rewrite_init() initializes data structures that are private +/* to this module. It should be called once before using the +/* actual rewriting routines. +/* +/* rewrite_proto() implements the client-server protocol: read +/* one rule set name and one address in external (quoted) form, +/* reply with the rewritten address in external form. +/* +/* rewrite_addr() rewrites an address string to another string. +/* Both input and output are in external (quoted) form. +/* +/* rewrite_tree() rewrites a parse tree with a single address to +/* another tree. A tree is a dummy node on top of a token list. +/* +/* local_context and remote_context provide domain names for +/* completing incomplete address forms. +/* STANDARDS +/* DIAGNOSTICS +/* Problems and transactions are logged to \fBsyslogd\fR(8) +/* or \fBpostlogd\fR(8). +/* BUGS +/* SEE ALSO +/* 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 <stdlib.h> +#include <string.h> + +#ifdef STRCASECMP_IN_STRINGS_H +#include <strings.h> +#endif + +/* Utility library. */ + +#include <msg.h> +#include <vstring.h> +#include <vstream.h> +#include <vstring_vstream.h> +#include <split_at.h> + +/* Global library. */ + +#include <mail_params.h> +#include <mail_proto.h> +#include <resolve_local.h> +#include <tok822.h> +#include <mail_conf.h> + +/* Application-specific. */ + +#include "trivial-rewrite.h" + +RWR_CONTEXT local_context = { + VAR_MYORIGIN, &var_myorigin, + VAR_MYDOMAIN, &var_mydomain, +}; + +RWR_CONTEXT remote_context = { + VAR_REM_RWR_DOMAIN, &var_remote_rwr_domain, + VAR_REM_RWR_DOMAIN, &var_remote_rwr_domain, +}; + +static VSTRING *ruleset; +static VSTRING *address; +static VSTRING *result; + +/* rewrite_tree - rewrite address according to rule set */ + +void rewrite_tree(RWR_CONTEXT *context, TOK822 *tree) +{ + TOK822 *colon; + TOK822 *domain; + TOK822 *bang; + TOK822 *local; + VSTRING *vstringval; + + /* + * XXX If you change this module, quote_822_local.c, or tok822_parse.c, + * be sure to re-run the tests under "make rewrite_clnt_test" and "make + * resolve_clnt_test" in the global directory. + */ + + /* + * Sanity check. + */ + if (tree->head == 0) + msg_panic("rewrite_tree: empty tree"); + + /* + * An empty address is a special case. + */ + if (tree->head == tree->tail + && tree->tail->type == TOK822_QSTRING + && VSTRING_LEN(tree->tail->vstr) == 0) + return; + + /* + * Treat a lone @ as if it were an empty address. + */ + if (tree->head == tree->tail + && tree->tail->type == '@') { + tok822_free_tree(tok822_sub_keep_before(tree, tree->tail)); + tok822_sub_append(tree, tok822_alloc(TOK822_QSTRING, "")); + return; + } + + /* + * Strip source route. + */ + if (tree->head->type == '@' + && (colon = tok822_find_type(tree->head, ':')) != 0 + && colon != tree->tail) + tok822_free_tree(tok822_sub_keep_after(tree, colon)); + + /* + * Optionally, transform address forms without @. + */ + if ((domain = tok822_rfind_type(tree->tail, '@')) == 0) { + + /* + * Swap domain!user to user@domain. + */ + if (var_swap_bangpath != 0 + && (bang = tok822_find_type(tree->head, '!')) != 0) { + tok822_sub_keep_before(tree, bang); + local = tok822_cut_after(bang); + tok822_free(bang); + tok822_sub_prepend(tree, tok822_alloc('@', (char *) 0)); + if (local) + tok822_sub_prepend(tree, local); + } + + /* + * Promote user%domain to user@domain. + */ + else if (var_percent_hack != 0 + && (domain = tok822_rfind_type(tree->tail, '%')) != 0) { + domain->type = '@'; + } + + /* + * Append missing @origin + */ + else if (var_append_at_myorigin != 0 + && REW_PARAM_VALUE(context->origin) != 0 + && REW_PARAM_VALUE(context->origin)[0] != 0) { + domain = tok822_sub_append(tree, tok822_alloc('@', (char *) 0)); + tok822_sub_append(tree, tok822_scan(REW_PARAM_VALUE(context->origin), + (TOK822 **) 0)); + } + } + + /* + * Append missing .domain, but leave broken forms ending in @ alone. This + * merely makes diagnostics more accurate by leaving bogus addresses + * alone. + * + * Backwards-compatibility warning: warn for "user@localhost" when there is + * no "localhost" in mydestination or in any other address class with an + * explicit domain list. + */ + if (var_append_dot_mydomain != 0 + && REW_PARAM_VALUE(context->domain) != 0 + && REW_PARAM_VALUE(context->domain)[0] != 0 + && (domain = tok822_rfind_type(tree->tail, '@')) != 0 + && domain != tree->tail + && tok822_find_type(domain, TOK822_DOMLIT) == 0 + && tok822_find_type(domain, '.') == 0) { + if (warn_compat_break_app_dot_mydomain + && (vstringval = domain->next->vstr) != 0) { + if (strcasecmp(vstring_str(vstringval), "localhost") != 0) { + msg_info("using backwards-compatible default setting " + VAR_APP_DOT_MYDOMAIN "=yes to rewrite \"%s\" to " + "\"%s.%s\"", vstring_str(vstringval), + vstring_str(vstringval), var_mydomain); + } else if (resolve_class("localhost") == RESOLVE_CLASS_DEFAULT) { + msg_info("using backwards-compatible default setting " + VAR_APP_DOT_MYDOMAIN "=yes to rewrite \"%s\" to " + "\"%s.%s\"; please add \"localhost\" to " + "mydestination or other address class", + vstring_str(vstringval), vstring_str(vstringval), + var_mydomain); + } + } + tok822_sub_append(tree, tok822_alloc('.', (char *) 0)); + tok822_sub_append(tree, tok822_scan(REW_PARAM_VALUE(context->domain), + (TOK822 **) 0)); + } + + /* + * Strip trailing dot at end of domain, but not dot-dot or @-dot. This + * merely makes diagnostics more accurate by leaving bogus addresses + * alone. + */ + if (tree->tail->type == '.' + && tree->tail->prev + && tree->tail->prev->type != '.' + && tree->tail->prev->type != '@') + tok822_free_tree(tok822_sub_keep_before(tree, tree->tail)); +} + +/* rewrite_proto - read request and send reply */ + +int rewrite_proto(VSTREAM *stream) +{ + RWR_CONTEXT *context; + TOK822 *tree; + + if (attr_scan(stream, ATTR_FLAG_STRICT, + RECV_ATTR_STR(MAIL_ATTR_RULE, ruleset), + RECV_ATTR_STR(MAIL_ATTR_ADDR, address), + ATTR_TYPE_END) != 2) + return (-1); + + if (strcmp(vstring_str(ruleset), MAIL_ATTR_RWR_LOCAL) == 0) + context = &local_context; + else if (strcmp(vstring_str(ruleset), MAIL_ATTR_RWR_REMOTE) == 0) + context = &remote_context; + else { + msg_warn("unknown context: %s", vstring_str(ruleset)); + return (-1); + } + + /* + * Sanity check. An address is supposed to be in externalized form. + */ + if (*vstring_str(address) == 0) { + msg_warn("rewrite_addr: null address"); + vstring_strcpy(result, vstring_str(address)); + } + + /* + * Convert the address from externalized (quoted) form to token list, + * rewrite it, and convert back. + */ + else { + tree = tok822_scan_addr(vstring_str(address)); + rewrite_tree(context, tree); + tok822_externalize(result, tree, TOK822_STR_DEFL); + tok822_free_tree(tree); + } + if (msg_verbose) + msg_info("`%s' `%s' -> `%s'", vstring_str(ruleset), + vstring_str(address), vstring_str(result)); + + attr_print(stream, ATTR_FLAG_NONE, + SEND_ATTR_INT(MAIL_ATTR_FLAGS, server_flags), + SEND_ATTR_STR(MAIL_ATTR_ADDR, vstring_str(result)), + ATTR_TYPE_END); + + if (vstream_fflush(stream) != 0) { + msg_warn("write rewrite reply: %m"); + return (-1); + } + return (0); +} + +/* rewrite_init - module initializations */ + +void rewrite_init(void) +{ + ruleset = vstring_alloc(100); + address = vstring_alloc(100); + result = vstring_alloc(100); +} |