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-rw-r--r--src/global/delivered_hdr.c195
1 files changed, 195 insertions, 0 deletions
diff --git a/src/global/delivered_hdr.c b/src/global/delivered_hdr.c
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+/*++
+/* NAME
+/* delivered_hdr 3
+/* SUMMARY
+/* process Delivered-To: headers
+/* SYNOPSIS
+/* #include <delivered_hdr.h>
+/*
+/* DELIVERED_HDR_INFO *delivered_hdr_init(stream, offset, flags)
+/* VSTREAM *stream;
+/* off_t offset;
+/* int flags;
+/*
+/* int delivered_hdr_find(info, address)
+/* DELIVERED_HDR_INFO *info;
+/* const char *address;
+/*
+/* void delivered_hdr_free(info)
+/* DELIVERED_HDR_INFO *info;
+/* DESCRIPTION
+/* This module processes addresses in Delivered-To: headers.
+/* These headers are added by some mail delivery systems, for the
+/* purpose of breaking mail forwarding loops. N.B. This solves
+/* a different problem than the Received: hop count limit. Hop
+/* counts are used to limit the impact of mail routing problems.
+/*
+/* delivered_hdr_init() extracts Delivered-To: header addresses
+/* from the specified message, and returns a table with the
+/* result. The file seek pointer is changed.
+/*
+/* delivered_hdr_find() looks up the address in the lookup table,
+/* and returns non-zero when the address was found. The
+/* address argument must be in internalized form.
+/*
+/* delivered_hdr_free() releases storage that was allocated by
+/* delivered_hdr_init().
+/*
+/* Arguments:
+/* .IP stream
+/* The open queue file.
+/* .IP offset
+/* Offset of the first message content record.
+/* .IP flags
+/* Zero, or the bit-wise OR ot:
+/* .RS
+/* .IP FOLD_ADDR_USER
+/* Case fold the address local part.
+/* .IP FOLD_ADDR_HOST
+/* Case fold the address domain part.
+/* .IP FOLD_ADDR_ALL
+/* Alias for (FOLD_ADDR_USER | FOLD_ADDR_HOST).
+/* .RE
+/* .IP info
+/* Extracted Delivered-To: addresses information.
+/* .IP address
+/* A recipient address, internal form.
+/* DIAGNOSTICS
+/* Fatal errors: out of memory.
+/* SEE ALSO
+/* mail_copy(3), producer of Delivered-To: and other headers.
+/* 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 <unistd.h>
+#include <string.h>
+#include <ctype.h>
+
+/* Utility library. */
+
+#include <msg.h>
+#include <mymalloc.h>
+#include <htable.h>
+#include <vstring.h>
+#include <vstream.h>
+#include <vstring_vstream.h>
+#include <stringops.h>
+
+/* Global library. */
+
+#include <record.h>
+#include <rec_type.h>
+#include <is_header.h>
+#include <quote_822_local.h>
+#include <header_opts.h>
+#include <delivered_hdr.h>
+#include <fold_addr.h>
+
+ /*
+ * Application-specific.
+ */
+struct DELIVERED_HDR_INFO {
+ int flags;
+ VSTRING *buf;
+ VSTRING *fold;
+ HTABLE *table;
+};
+
+#define STR(x) vstring_str(x)
+
+/* delivered_hdr_init - extract delivered-to information from the message */
+
+DELIVERED_HDR_INFO *delivered_hdr_init(VSTREAM *fp, off_t offset, int flags)
+{
+ char *cp;
+ DELIVERED_HDR_INFO *info;
+ const HEADER_OPTS *hdr;
+ int curr_type;
+ int prev_type;
+
+ /*
+ * Sanity check.
+ */
+ info = (DELIVERED_HDR_INFO *) mymalloc(sizeof(*info));
+ info->flags = flags;
+ info->buf = vstring_alloc(10);
+ info->fold = vstring_alloc(10);
+ info->table = htable_create(0);
+
+ if (vstream_fseek(fp, offset, SEEK_SET) < 0)
+ msg_fatal("seek queue file %s: %m", VSTREAM_PATH(fp));
+
+ /*
+ * XXX Assume that mail_copy() produces delivered-to headers that fit in
+ * a REC_TYPE_NORM or REC_TYPE_CONT record. Lowercase the delivered-to
+ * addresses for consistency.
+ *
+ * XXX Don't get bogged down by gazillions of delivered-to headers.
+ */
+#define DELIVERED_HDR_LIMIT 1000
+
+ for (prev_type = REC_TYPE_NORM;
+ info->table->used < DELIVERED_HDR_LIMIT
+ && ((curr_type = rec_get(fp, info->buf, 0)) == REC_TYPE_NORM
+ || curr_type == REC_TYPE_CONT);
+ prev_type = curr_type) {
+ if (prev_type != REC_TYPE_NORM)
+ continue;
+ if (is_header(STR(info->buf))) {
+ if ((hdr = header_opts_find(STR(info->buf))) != 0
+ && hdr->type == HDR_DELIVERED_TO) {
+ cp = STR(info->buf) + strlen(hdr->name) + 1;
+ while (ISSPACE(*cp))
+ cp++;
+ cp = fold_addr(info->fold, cp, info->flags);
+ if (msg_verbose)
+ msg_info("delivered_hdr_init: %s", cp);
+ htable_enter(info->table, cp, (void *) 0);
+ }
+ } else if (ISSPACE(STR(info->buf)[0])) {
+ continue;
+ } else {
+ break;
+ }
+ }
+ return (info);
+}
+
+/* delivered_hdr_find - look up recipient in delivered table */
+
+int delivered_hdr_find(DELIVERED_HDR_INFO *info, const char *address)
+{
+ HTABLE_INFO *ht;
+ const char *addr_key;
+
+ /*
+ * mail_copy() uses quote_822_local() when writing the Delivered-To:
+ * header. We must therefore apply the same transformation when looking
+ * up the recipient. Lowercase the delivered-to address for consistency.
+ */
+ quote_822_local(info->buf, address);
+ addr_key = fold_addr(info->fold, STR(info->buf), info->flags);
+ ht = htable_locate(info->table, addr_key);
+ return (ht != 0);
+}
+
+/* delivered_hdr_free - destructor */
+
+void delivered_hdr_free(DELIVERED_HDR_INFO *info)
+{
+ vstring_free(info->buf);
+ vstring_free(info->fold);
+ htable_free(info->table, (void (*) (void *)) 0);
+ myfree((void *) info);
+}