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-rw-r--r--src/rewrite.c841
1 files changed, 841 insertions, 0 deletions
diff --git a/src/rewrite.c b/src/rewrite.c
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index 0000000..f720f99
--- /dev/null
+++ b/src/rewrite.c
@@ -0,0 +1,841 @@
+/*************************************************
+* Exim - an Internet mail transport agent *
+*************************************************/
+
+/* Copyright (c) University of Cambridge 1995 - 2018 */
+/* See the file NOTICE for conditions of use and distribution. */
+
+/* Functions concerned with rewriting headers */
+
+
+#include "exim.h"
+
+/* Names for testing rewriting */
+
+static const char *rrname[] = {
+ " sender",
+ " from",
+ " to",
+ " cc",
+ " bcc",
+ "reply-to",
+ "env-from",
+ " env-to"
+};
+
+/* Structure and table for finding source of address for debug printing */
+
+typedef struct where_list_block {
+ int bit;
+ const uschar *string;
+} where_list_block;
+
+static where_list_block where_list[] = {
+ { rewrite_sender, CUS"sender:" },
+ { rewrite_from, CUS"from:" },
+ { rewrite_to, CUS"to:" },
+ { rewrite_cc, CUS"cc:" },
+ { rewrite_bcc, CUS"bcc:" },
+ { rewrite_replyto, CUS"reply-to:" },
+ { rewrite_envfrom, CUS"env-from" },
+ { rewrite_envto, CUS"env-to" },
+ { rewrite_smtp, CUS"smtp recipient" },
+ { rewrite_smtp|rewrite_smtp_sender, CUS"smtp sender" }
+};
+
+static int where_list_size = sizeof(where_list)/sizeof(where_list_block);
+
+
+
+/*************************************************
+* Ensure an address is qualified *
+*************************************************/
+
+/*
+Arguments:
+ s address to check
+ is_recipient TRUE if a recipient address; FALSE if a sender address
+
+Returns: fully-qualified address
+*/
+
+const uschar *
+rewrite_address_qualify(const uschar *s, BOOL is_recipient)
+{
+return parse_find_at(s)
+ ? s : string_sprintf("%s@%s", s,
+ is_recipient ? qualify_domain_recipient : qualify_domain_sender);
+}
+
+
+
+/*************************************************
+* Rewrite a single address *
+*************************************************/
+
+/* The yield is the input address if there is no rewriting to be done. Assume
+the input is a valid address, except in the case of SMTP-time rewriting, which
+is handled specially. When this function is called while processing filter and
+forward files, the uid may be that of the user. Ensure it is reset while
+expanding a replacement, in case that involves file lookups.
+
+Arguments:
+ s address to rewrite
+ flag indicates where this address comes from; it must match the
+ flags in the rewriting rule
+ whole if not NULL, set TRUE if any rewriting rule contained the
+ "whole" bit and it is a header that is being rewritten
+ add_header if TRUE and rewriting occurs, add an "X-rewrote-xxx" header
+ if headers are in existence; this should be TRUE only when
+ a message is being received, not during delivery
+ name name of header, for use when adding X-rewrote-xxxx
+ rewrite_rules chain of rewriting rules
+
+Returns: new address if rewritten; the input address if no change;
+ for a header rewrite, if the "whole" bit is set, the entire
+ rewritten address is returned, not just the active bit.
+*/
+
+const uschar *
+rewrite_one(const uschar *s, int flag, BOOL *whole, BOOL add_header, uschar *name,
+ rewrite_rule *rewrite_rules)
+{
+const uschar *yield = s;
+const uschar *subject = s;
+uschar *domain = NULL;
+BOOL done = FALSE;
+int rule_number = 1;
+int yield_start = 0, yield_end = 0;
+
+if (whole) *whole = FALSE;
+
+/* Scan the rewriting rules */
+
+for (rewrite_rule * rule = rewrite_rules;
+ rule && !done;
+ rule_number++, rule = rule->next)
+ {
+ int start, end, pdomain;
+ int count = 0;
+ uschar *save_localpart;
+ const uschar *save_domain;
+ uschar *error, *new;
+ const uschar * newparsed;
+
+ /* Ensure that the flag matches the flags in the rule. */
+
+ if (!(rule->flags & flag)) continue;
+
+ /* Come back here for a repeat after a successful rewrite. We do this
+ only so many times. */
+
+ REPEAT_RULE:
+
+ /* If this is an SMTP-time rewrite, the pattern must be a regex and
+ the subject may have any structure. No local part or domain variables
+ can be set for the expansion. We expand the pattern in order to be consistent
+ with the other kinds of rewrite, where expansion happens inside
+ match_address_list(). */
+
+ if (flag & rewrite_smtp)
+ {
+ uschar *key = expand_string(rule->key);
+ if (!key)
+ {
+ if (!f.expand_string_forcedfail)
+ log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand \"%s\" while "
+ "checking for SMTP rewriting: %s", rule->key, expand_string_message);
+ continue;
+ }
+ if (match_check_string(subject, key, 0, TRUE, FALSE, FALSE, NULL) != OK)
+ continue;
+ new = expand_string(rule->replacement);
+ }
+
+ /* All other rewrites expect the input to be a valid address, so local part
+ and domain variables can be set for expansion. For the first rule, to be
+ applied to this address, domain will be NULL and needs to be set. */
+
+ else
+ {
+ if (!domain) domain = Ustrrchr(subject, '@') + 1;
+
+ /* Use the general function for matching an address against a list (here
+ just one item, so use the "impossible value" separator UCHAR_MAX+1). */
+
+ if (match_address_list(subject, FALSE, TRUE, CUSS &(rule->key), NULL, 0,
+ UCHAR_MAX + 1, NULL) != OK)
+ continue;
+
+ /* The source address matches, and numerical variables have been
+ set up. If the replacement string consists of precisely "*" then no
+ rewriting is required for this address - the behaviour is as for "fail"
+ in the replacement expansion, but assuming the quit flag. */
+
+ if (Ustrcmp(rule->replacement, "*") == 0) break;
+
+ /* Otherwise, expand the replacement string. Set $local_part and $domain to
+ the appropriate values, restoring whatever value they previously had
+ afterwards. */
+
+ save_localpart = deliver_localpart;
+ save_domain = deliver_domain;
+
+ /* We have subject pointing to "localpart@domain" and domain pointing to
+ the domain. Temporarily terminate the local part so that it can be
+ set up as an expansion variable */
+
+ domain[-1] = 0;
+ deliver_localpart = US subject;
+ deliver_domain = domain;
+
+ new = expand_string(rule->replacement);
+
+ domain[-1] = '@';
+ deliver_localpart = save_localpart;
+ deliver_domain = save_domain;
+ }
+
+ /* If the expansion failed with the "forcedfail" flag, don't generate
+ an error - just give up on this rewriting rule. If the "q" flag is set,
+ give up altogether. For other expansion failures we have a configuration
+ error. */
+
+ if (!new)
+ {
+ if (f.expand_string_forcedfail)
+ { if (rule->flags & rewrite_quit) break; else continue; }
+
+ expand_string_message = expand_hide_passwords(expand_string_message);
+
+ log_write(0, LOG_MAIN|LOG_PANIC, "Expansion of %s failed while rewriting: "
+ "%s", rule->replacement, expand_string_message);
+ break;
+ }
+
+ /* Check the what has been generated is a valid RFC 2822 address. Only
+ envelope from or SMTP sender is permitted to be rewritten as <>.*/
+
+ newparsed = parse_extract_address(new, &error, &start, &end, &pdomain,
+ flag == rewrite_envfrom || flag == (rewrite_smtp|rewrite_smtp_sender));
+
+ if (!newparsed)
+ {
+ log_write(0, LOG_MAIN|LOG_PANIC, "Rewrite of %s yielded unparseable "
+ "address: %s in address %s", subject, error, new);
+ break; /* Give up on this address */
+ }
+
+ /* A non-null unqualified address can be qualified if requested. Otherwise,
+ this is an error unless it's the empty address in circumstances where that is
+ permitted. */
+
+ if (pdomain == 0 && (*newparsed != 0 ||
+ (flag != rewrite_envfrom && flag != (rewrite_smtp|rewrite_smtp_sender))))
+ {
+ if (rule->flags & rewrite_qualify)
+ {
+ newparsed = rewrite_address_qualify(newparsed, TRUE);
+ new = string_sprintf("%.*s%s%.*s", start, new, newparsed,
+ Ustrlen(new) - end, new + end);
+ end = start + Ustrlen(newparsed);
+ }
+ else
+ {
+ log_write(0, LOG_MAIN|LOG_PANIC, "Rewrite of %s yielded unqualified "
+ "address \"%s\"", subject, new);
+ break; /* Give up on this address */
+ }
+ }
+
+ /* We have a validly rewritten address */
+
+ if (LOGGING(address_rewrite) || (debug_selector & D_rewrite) != 0)
+ {
+ const uschar *where = CUS"?";
+
+ for (int i = 0; i < where_list_size; i++)
+ if (flag == where_list[i].bit)
+ {
+ where = where_list[i].string;
+ break;
+ }
+ log_write(L_address_rewrite,
+ LOG_MAIN, "\"%s\" from %s rewritten as \"%s\" by rule %d",
+ yield, where, new, rule_number);
+ }
+
+ /* A header will only actually be added if header_last is non-NULL,
+ i.e. during message reception or delivery, but add_header should not
+ be set TRUE during delivery, as otherwise multiple instances of the header
+ can fill up the -H file and make it embarrassingly large. We don't need
+ to set header_rewritten because the -H file always gets written at the end
+ of message reception. */
+
+ if (add_header)
+ header_add(htype_old, "X-rewrote-%s: %s\n", name, subject);
+
+ /* Handle the case when replacement of the whole address is possible.
+ This happens only when whole is not NULL and we are rewriting a header.
+ If *whole is already TRUE it means that a previous rule had the w
+ flag set and so we must preserve the non-active portion of the current
+ subject unless the current rule also has the w flag set. */
+
+ if (whole && (flag & rewrite_all_headers))
+ {
+ /* Current rule has the w flag set. We must ensure the phrase parts
+ are syntactically valid if they are present. */
+
+ if (rule->flags & rewrite_whole)
+ {
+ if (start > 0 && new[start-1] == '<')
+ {
+ uschar *p1 = new + start - 1;
+ uschar *p2 = new + end + 1;
+ const uschar *pf1, *pf2;
+
+ while (p1 > new && p1[-1] == ' ') p1--;
+ pf1 = parse_fix_phrase(new, p1 - new);
+ while (*p2 == ' ') p2++;
+ pf2 = parse_fix_phrase(p2, Ustrlen(p2));
+
+ start = Ustrlen(pf1) + start + new - p1;
+ end = start + Ustrlen(newparsed);
+ new = string_sprintf("%s%.*s%s", pf1, (int)(p2 - p1), p1, pf2);
+ }
+
+ /* Now accept the whole thing */
+
+ yield = new;
+ yield_start = start;
+ yield_end = end;
+ subject = newparsed;
+ *whole = TRUE;
+ }
+
+ /* Current rule does not have the w flag set; if not previously
+ done any whole rewriting, behave in non-whole manner. */
+
+ else if (!*whole) goto NEVER_WHOLE;
+
+ /* Current rule does not have the w flag set, but a previous
+ rule did rewrite the whole address. Thus yield and subject will be
+ different. Preserve the previous non-active part of the address. */
+
+ else
+ {
+ subject = newparsed;
+ new = string_sprintf("%.*s%s%n%s",
+ yield_start, yield, subject, &end, yield + yield_end);
+ yield_end = end;
+ yield = new;
+ }
+ }
+
+ /* Rule just rewrites active part, or handling an envelope. This
+ code is obeyed only when all rules so far have not done "whole"
+ replacement. */
+
+ else
+ {
+ NEVER_WHOLE:
+ subject = yield = newparsed;
+ }
+
+ domain = NULL; /* Reset for next rule */
+
+ /* If no further rewrites are to be done, set the done flag. This allows
+ repeats of the current rule if configured before breaking the loop. */
+
+ if (rule->flags & rewrite_quit) done = TRUE;
+
+ /* Allow the current rule to be applied up to 10 times if
+ requested. */
+
+ if (rule->flags & rewrite_repeat)
+ {
+ if (count++ < 10) goto REPEAT_RULE;
+ log_write(0, LOG_MAIN|LOG_PANIC, "rewrite rule repeat ignored after 10 "
+ "times");
+ }
+ }
+
+/* Unset expansion numeric variables, and that's it. */
+
+expand_nmax = -1;
+return yield;
+}
+
+
+
+/*************************************************
+* Ensure qualification and rewrite *
+*************************************************/
+
+/* This function is called for envelope addresses, the boolean specifying
+whether a recipient or a sender. It must first of all ensure the address is
+fully qualified, and then apply any relevant re-writing rules. The add-header
+flag causes a header to be added, recording the old address. This is marked
+"old", so that it is never transported anywhere; it exists for local checking
+and debugging purposes.
+
+Arguments:
+ s the address to be considered
+ is_recipient TRUE for recipient addresses; FALSE otherwise
+ add_header add "X-rewrote-xxx" header when rewriting; this is
+ set TRUE only for calls from the reception functions
+ rewrite_rules points to chain of rewrite rules
+ existflags bits indicating which headers there are rewrites for
+ (just an optimisation)
+
+Returns: possibly rewritten address
+*/
+
+const uschar *
+rewrite_address(const uschar *s, BOOL is_recipient, BOOL add_header,
+ rewrite_rule *rewrite_rules, int existflags)
+{
+int flag = is_recipient ? rewrite_envto : rewrite_envfrom;
+
+s = rewrite_address_qualify(s, is_recipient);
+if (existflags & flag)
+ {
+ const uschar *new = rewrite_one(s, flag, NULL, add_header, is_recipient?
+ US"original-recipient" : US"sender", rewrite_rules);
+ if (new != s) s = new;
+ }
+return s;
+}
+
+
+
+/*************************************************
+* Qualify and possibly rewrite one header *
+*************************************************/
+
+/* This is called only from rewrite_header() below, either when reading a
+message. or when routing, in order to rewrite addresses that get changed by a
+router. This is normally the addition of full qualification to a partial
+domain. The first rewriting rule in this case is "change routed_old into
+routed_new", and it applies to all header lines that contain addresses. Then
+header-specific rewriting rules are applied.
+
+Before rewriting can be done, addresses without domains have to be qualified.
+This should only be done for messages from "local" senders. This is a difficult
+concept to pin down, what with the use of SMTP both as a submission and as a
+transmission protocol. Exim normally requires incoming SMTP to contain fully-
+qualified addresses, but there are options to permit unqualified ones from
+certain hosts. For those hosts only, addresses in headers can also be
+qualified. For other hosts, unqualified addresses in headers do not get touched
+in any way. For locally sourced messages, unqualified addresses always get
+qualified, except when -bnq is used to explicitly suppress this.
+
+Arguments:
+ h pointer to header line block
+ flag indicates which header this is
+ routed_old if not NULL, this is a rewrite caused by a router, changing
+ this domain into routed_new
+ routed_new new routed domain if routed_old is not NULL
+ rewrite_rules points to chain of rewriting rules
+ existflags bits indicating which rewrites exist
+ replace if TRUE, insert the new header in the chain after the old
+ one, and mark the old one "replaced"
+
+Returns: NULL if header unchanged; otherwise the rewritten header
+*/
+
+static header_line *
+rewrite_one_header(header_line *h, int flag,
+ const uschar *routed_old, const uschar *routed_new,
+ rewrite_rule *rewrite_rules, int existflags, BOOL replace)
+{
+int lastnewline = 0;
+header_line *newh = NULL;
+rmark function_reset_point = store_mark();
+uschar *s = Ustrchr(h->text, ':') + 1;
+while (isspace(*s)) s++;
+
+DEBUG(D_rewrite)
+ debug_printf("rewrite_one_header: type=%c:\n %s", h->type, h->text);
+
+f.parse_allow_group = TRUE; /* Allow group syntax */
+
+/* Loop for multiple addresses in the header. We have to go through them all
+in case any need qualifying, even if there's no rewriting. Pathological headers
+may have thousands of addresses in them, so cause the store to be reset for
+any that don't actually get rewritten. We also play silly games for those that
+_are_ rewritten so as to avoid runaway store usage for these kinds of header.
+We want to avoid keeping store for any intermediate versions. */
+
+while (*s)
+ {
+ uschar *sprev;
+ uschar *ss = parse_find_address_end(s, FALSE);
+ uschar *recipient, *new;
+ rmark loop_reset_point = store_mark();
+ uschar *errmess = NULL;
+ BOOL changed = FALSE;
+ int terminator = *ss;
+ int start, end, domain;
+
+ /* Temporarily terminate the string at this point, and extract the
+ operative address within. Then put back the terminator and prepare for
+ the next address, saving the start of the old one. */
+
+ *ss = 0;
+ recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
+
+ *ss = terminator;
+ sprev = s;
+ s = ss + (terminator? 1:0);
+ while (isspace(*s)) s++;
+
+ /* There isn't much we can do for syntactic disasters at this stage.
+ Pro tem (possibly for ever) ignore them.
+ If we got nothing, then there was any sort of error: non-parsable address,
+ empty address, overlong addres. Sometimes the result matters, sometimes not.
+ It seems this function is called for *any* header we see. */
+
+
+ if (!recipient)
+ {
+#if 0
+ /* FIXME:
+ This was(!) an attempt tho handle empty rewrits, but seemingly it
+ needs more effort to decide if the returned empty address matters.
+ Now this will now break test 471 again.
+
+ 471 fails now because it uses an overlong address, for wich parse_extract_address()
+ returns an empty address (which was not expected).
+
+ Checking the output and exit if rewrite_rules or routed_old are present
+ isn't a good idea either: It's enough to have *any* rewrite rule
+ in the configuration plus "To: undisclosed recpients:;" to exit(), which
+ is not what we want.
+ */
+
+ if (rewrite_rules || routed_old)
+ {
+ log_write(0, LOG_MAIN, "rewrite: %s", errmess);
+ exim_exit(EXIT_FAILURE);
+ }
+#endif
+ loop_reset_point = store_reset(loop_reset_point);
+ continue;
+ }
+
+ /* If routed_old is not NULL, this is a rewrite caused by a router,
+ consisting of changing routed_old into routed_new, and applying to all
+ headers. If the header address has no domain, it is excluded, since a router
+ rewrite affects domains only. The new value should always be fully qualified,
+ but it may be something that has an explicit re-write rule set, so we need to
+ check the configured rules subsequently as well. (Example: there's an
+ explicit rewrite turning *.foo.com into foo.com, and an address is supplied
+ as abc@xyz, which the DNS lookup turns into abc@xyz.foo.com). However, if no
+ change is made here, don't bother carrying on. */
+
+ if (routed_old != NULL)
+ {
+ if (domain <= 0 || strcmpic(recipient+domain, routed_old) != 0) continue;
+ recipient[domain-1] = 0;
+ new = string_sprintf("%s@%s", recipient, routed_new);
+ DEBUG(D_rewrite)
+ {
+ recipient[domain-1] = '@';
+ debug_printf("%s rewritten by router as %s\n", recipient, new);
+ }
+ recipient = new;
+ changed = TRUE;
+ }
+
+ /* This is not a router-inspired rewrite. Ensure the address is fully
+ qualified if that is permitted. If an unqualified address was received
+ from a host that isn't listed, do not continue rewriting this address.
+ Sender, From or Reply-To headers are treated as senders, the rest as
+ recipients. This matters only when there are different qualify strings. */
+
+ else
+ {
+ BOOL is_recipient =
+ (flag & (rewrite_sender | rewrite_from | rewrite_replyto)) == 0;
+ /* deconst ok as recipient was notconst */
+ new = US rewrite_address_qualify(recipient, is_recipient);
+ changed = (new != recipient);
+ recipient = new;
+
+ /* Can only qualify if permitted; if not, no rewrite. */
+
+ if (changed && ((is_recipient && !f.allow_unqualified_recipient) ||
+ (!is_recipient && !f.allow_unqualified_sender)))
+ {
+ loop_reset_point = store_reset(loop_reset_point);
+ continue;
+ }
+ }
+
+ /* If there are rewrite rules for this type of header, apply
+ them. This test is just for efficiency, to save scanning the rules
+ in cases when nothing is going to change. If any rewrite rule had the
+ "whole" flag set, adjust the pointers so that the whole address gets
+ replaced, except possibly a final \n. */
+
+ if ((existflags & flag) != 0)
+ {
+ BOOL whole;
+ /* deconst ok as recipient was notconst */
+ new = US rewrite_one(recipient, flag, &whole, FALSE, NULL, rewrite_rules);
+ if (new != recipient)
+ {
+ changed = TRUE;
+ if (whole)
+ {
+ start = 0;
+ end = ss - sprev;
+ if (sprev[end-1] == '\n') end--;
+ }
+ }
+ }
+
+ /* If nothing has changed, lose all dynamic store obtained in this loop, and
+ move on to the next address. We can't reset to the function start store
+ point, because we may have a rewritten line from a previous time round the
+ loop. */
+
+ if (!changed) loop_reset_point = store_reset(loop_reset_point);
+
+ /* If the address has changed, create a new header containing the
+ rewritten address. We do not need to set the chain pointers at this
+ stage. We want to avoid using more and more memory if the header is very long
+ and contains lots and lots of rewritten addresses. Therefore, we build the
+ new text string in malloc store, then at the end we reset dynamic store
+ before copying the new header to a new block (and then freeing the malloc
+ block). The header must end up in dynamic store so that it's freed at the end
+ of receiving a message. */
+
+ else
+ {
+ int remlen;
+ int newlen = Ustrlen(new);
+ int oldlen = end - start;
+
+ header_line * prev = newh ? newh : h;
+ uschar * newt = store_get_perm(prev->slen - oldlen + newlen + 4, TRUE);
+ uschar * newtstart = newt;
+
+ int type = prev->type;
+ int slen = prev->slen - oldlen + newlen;
+
+ /* Build the new header text by copying the old and putting in the
+ replacement. This process may make the header substantially longer
+ than it was before - qualification of a list of bare addresses can
+ often do this - so we stick in a newline after the re-written address
+ if it has increased in length and ends more than 40 characters in. In
+ fact, the code is not perfect, since it does not scan for existing
+ newlines in the header, but it doesn't seem worth going to that
+ amount of trouble. */
+
+ Ustrncpy(newt, prev->text, sprev - prev->text + start);
+ newt += sprev - prev->text + start;
+ *newt = 0;
+ Ustrcat(newt, new);
+ newt += newlen;
+ remlen = s - (sprev + end);
+ if (remlen > 0)
+ {
+ Ustrncpy(newt, sprev + end, remlen);
+ newt += remlen;
+ *newt = 0;
+ }
+
+ /* Must check that there isn't a newline here anyway; in particular, there
+ will be one at the very end of the header, where we DON'T want to insert
+ another one! The pointer s has been skipped over white space, so just
+ look back to see if the last non-space-or-tab was a newline. */
+
+ if (newlen > oldlen && newt - newtstart - lastnewline > 40)
+ {
+ uschar *p = s - 1;
+ while (p >= prev->text && (*p == ' ' || *p == '\t')) p--;
+ if (*p != '\n')
+ {
+ lastnewline = newt - newtstart;
+ Ustrcat(newt, US"\n\t");
+ slen += 2;
+ }
+ }
+
+ /* Finally, the remaining unprocessed addresses, if any. */
+
+ Ustrcat(newt, s);
+
+ DEBUG(D_rewrite) debug_printf("newlen=%d newtype=%c newtext:\n%s",
+ slen, type, newtstart);
+
+ /* Compute the length of the rest of the header line before we possibly
+ flatten a previously rewritten copy. */
+
+ remlen = (s - prev->text) - oldlen + newlen;
+
+ /* We have the new text in a malloc block. That enables us to release all
+ the memory that has been used, back to the point at which the function was
+ entered. Then set up a new header in dynamic store. This will override a
+ rewritten copy from a previous time round this loop. */
+
+ store_reset(function_reset_point);
+ function_reset_point = store_mark();
+ newh = store_get(sizeof(header_line), FALSE);
+ newh->type = type;
+ newh->slen = slen;
+ newh->text = string_copyn(newtstart, slen);
+
+ /* Set up for scanning the rest of the header */
+
+ s = newh->text + remlen;
+ DEBUG(D_rewrite) debug_printf("remainder: %s", (*s == 0)? US"\n" : s);
+ }
+ }
+
+f.parse_allow_group = FALSE; /* Reset group flags */
+f.parse_found_group = FALSE;
+
+/* If a rewrite happened and "replace" is true, put the new header into the
+chain following the old one, and mark the old one as replaced. */
+
+if (newh != NULL && replace)
+ {
+ newh->next = h->next;
+ if (newh->next == NULL) header_last = newh;
+ h->type = htype_old;
+ h->next = newh;
+ }
+
+return newh;
+}
+
+
+
+
+/*************************************************
+* Rewrite a header line *
+*************************************************/
+
+/* This function may be passed any old header line. It must detect those which
+contain addresses, then then apply any rewriting rules that apply. If
+routed_old is NULL, only the configured rewriting rules are consulted.
+Otherwise, the rewriting rule is "change routed_old into routed_new", and it
+applies to all header lines that contain addresses. Then header-specific
+rewriting rules are applied.
+
+The old header line is flagged as "old". Old headers are saved on the spool for
+debugging but are never sent to any recipients.
+
+Arguments:
+ h header line to rewrite
+ routed_old if not NULL, this is a rewrite caused by a router, changing
+ this domain into routed_new
+ routed_new new routed domain if routed_old is not NULL
+ rewrite_rules points to chain of rewrite rules
+ existflags bits indicating which rewrites exist
+ replace if TRUE, the new header is inserted into the header chain
+ after the old one, and the old one is marked replaced
+
+Returns: NULL if header unchanged; otherwise the rewritten header
+*/
+
+header_line *
+rewrite_header(header_line *h,
+ const uschar *routed_old, const uschar *routed_new,
+ rewrite_rule *rewrite_rules, int existflags, BOOL replace)
+{
+int flag;
+switch (h->type)
+ {
+ case htype_sender: flag = rewrite_sender; break;
+ case htype_from: flag = rewrite_from; break;
+ case htype_to: flag = rewrite_to; break;
+ case htype_cc: flag = rewrite_cc; break;
+ case htype_bcc: flag = rewrite_bcc; break;
+ case htype_reply_to: flag = rewrite_replyto; break;
+ default: return NULL;
+ }
+return rewrite_one_header(h, flag, routed_old, routed_new,
+ rewrite_rules, existflags, replace);
+}
+
+
+
+/************************************************
+* Test rewriting rules *
+************************************************/
+
+/* Called from the mainline as a result of the -brw option. Test the
+address for all possible cases.
+
+Argument: the address to test
+Returns: nothing
+*/
+
+void
+rewrite_test(const uschar *s)
+{
+uschar *recipient, *error;
+int start, end, domain;
+BOOL done_smtp = FALSE;
+
+if (rewrite_existflags == 0)
+ {
+ printf("No rewrite rules are defined\n");
+ return;
+ }
+
+/* Do SMTP rewrite only if a rule with the S flag exists. Allow <> by
+pretending it is a sender. */
+
+if ((rewrite_existflags & rewrite_smtp) != 0)
+ {
+ const uschar * new = rewrite_one(s, rewrite_smtp|rewrite_smtp_sender, NULL,
+ FALSE, US"", global_rewrite_rules);
+ if (new != s)
+ {
+ if (*new == 0)
+ printf(" SMTP: <>\n");
+ else
+ printf(" SMTP: %s\n", new);
+ done_smtp = TRUE;
+ }
+ }
+
+/* Do the other rewrites only if a rule without the S flag exists */
+
+if ((rewrite_existflags & ~rewrite_smtp) == 0) return;
+
+/* Qualify if necessary before extracting the address */
+
+if (parse_find_at(s) == NULL)
+ s = string_sprintf("%s@%s", s, qualify_domain_recipient);
+
+recipient = parse_extract_address(s, &error, &start, &end, &domain, FALSE);
+
+if (!recipient)
+ {
+ if (!done_smtp)
+ printf("Syntax error in %s\n%c%s\n", s, toupper(error[0]), error+1);
+ return;
+ }
+
+for (int i = 0; i < 8; i++)
+ {
+ BOOL whole = FALSE;
+ int flag = 1 << i;
+ const uschar * new = rewrite_one(recipient, flag, &whole, FALSE, US"",
+ global_rewrite_rules);
+ printf("%s: ", rrname[i]);
+ if (*new == 0)
+ printf("<>\n");
+ else if (whole || (flag & rewrite_all_headers) == 0)
+ printf("%s\n", CS new);
+ else printf("%.*s%s%s\n", start, s, new, s+end);
+ }
+}
+
+/* End of rewrite.c */
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