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-rw-r--r--src/mslookup/mdns_msg.c261
1 files changed, 0 insertions, 261 deletions
diff --git a/src/mslookup/mdns_msg.c b/src/mslookup/mdns_msg.c
deleted file mode 100644
index da65fef..0000000
--- a/src/mslookup/mdns_msg.c
+++ /dev/null
@@ -1,261 +0,0 @@
-/* High level mDNS encoding and decoding functions for whole messages:
- * Request message (header, question)
- * Answer message (header, resource record 1, ... resource record N)*/
-
-/* Copyright 2019 by sysmocom s.f.m.c. GmbH <info@sysmocom.de>
- *
- * All Rights Reserved
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-#include <errno.h>
-#include <string.h>
-#include <osmocom/hlr/logging.h>
-#include <osmocom/mslookup/mdns_msg.h>
-
-/*! Encode request message into one mDNS packet, consisting of the header section and one question section.
- * \returns 0 on success, -EINVAL on error.
- */
-int osmo_mdns_msg_request_encode(void *ctx, struct msgb *msg, const struct osmo_mdns_msg_request *req)
-{
- struct osmo_mdns_rfc_header hdr = {0};
- struct osmo_mdns_rfc_question qst = {0};
-
- hdr.id = req->id;
- hdr.qdcount = 1;
- osmo_mdns_rfc_header_encode(msg, &hdr);
-
- qst.domain = req->domain;
- qst.qtype = req->type;
- qst.qclass = OSMO_MDNS_RFC_CLASS_IN;
- if (osmo_mdns_rfc_question_encode(ctx, msg, &qst) != 0)
- return -EINVAL;
-
- return 0;
-}
-
-/*! Decode request message from a mDNS packet, consisting of the header section and one question section.
- * \returns allocated request message on success, NULL on error.
- */
-struct osmo_mdns_msg_request *osmo_mdns_msg_request_decode(void *ctx, const uint8_t *data, size_t data_len)
-{
- struct osmo_mdns_rfc_header hdr = {0};
- size_t hdr_len = sizeof(struct osmo_mdns_rfc_header);
- struct osmo_mdns_rfc_question* qst = NULL;
- struct osmo_mdns_msg_request *ret = NULL;
-
- if (data_len < hdr_len || osmo_mdns_rfc_header_decode(data, hdr_len, &hdr) != 0 || hdr.qr != 0)
- return NULL;
-
- qst = osmo_mdns_rfc_question_decode(ctx, data + hdr_len, data_len - hdr_len);
- if (!qst)
- return NULL;
-
- ret = talloc_zero(ctx, struct osmo_mdns_msg_request);
- ret->id = hdr.id;
- ret->domain = talloc_strdup(ret, qst->domain);
- ret->type = qst->qtype;
-
- talloc_free(qst);
- return ret;
-}
-
-/*! Initialize the linked list for resource records in a answer message. */
-void osmo_mdns_msg_answer_init(struct osmo_mdns_msg_answer *ans)
-{
- *ans = (struct osmo_mdns_msg_answer){};
- INIT_LLIST_HEAD(&ans->records);
-}
-
-/*! Encode answer message into one mDNS packet, consisting of the header section and N resource records.
- *
- * To keep things simple, this sends the domain with each resource record. Other DNS implementations make use of
- * "message compression", which would send a question section with the domain before the resource records, and then
- * point inside each resource record with an offset back to the domain in the question section (RFC 1035 4.1.4).
- * \returns 0 on success, -EINVAL on error.
- */
-int osmo_mdns_msg_answer_encode(void *ctx, struct msgb *msg, const struct osmo_mdns_msg_answer *ans)
-{
- struct osmo_mdns_rfc_header hdr = {0};
- struct osmo_mdns_record *ans_record;
-
- hdr.id = ans->id;
- hdr.qr = 1;
- hdr.ancount = llist_count(&ans->records);
- osmo_mdns_rfc_header_encode(msg, &hdr);
-
- llist_for_each_entry(ans_record, &ans->records, list) {
- struct osmo_mdns_rfc_record rec = {0};
-
- rec.domain = ans->domain;
- rec.type = ans_record->type;
- rec.class = OSMO_MDNS_RFC_CLASS_IN;
- rec.ttl = 0;
- rec.rdlength = ans_record->length;
- rec.rdata = ans_record->data;
-
- if (osmo_mdns_rfc_record_encode(ctx, msg, &rec) != 0)
- return -EINVAL;
- }
-
- return 0;
-}
-
-/*! Decode answer message from a mDNS packet.
- *
- * Answer messages must consist of one header and one or more resource records. An additional question section or
- * message compression (RFC 1035 4.1.4) are not supported.
-* \returns allocated answer message on success, NULL on error.
- */
-struct osmo_mdns_msg_answer *osmo_mdns_msg_answer_decode(void *ctx, const uint8_t *data, size_t data_len)
-{
- struct osmo_mdns_rfc_header hdr = {};
- size_t hdr_len = sizeof(struct osmo_mdns_rfc_header);
- struct osmo_mdns_msg_answer *ret = talloc_zero(ctx, struct osmo_mdns_msg_answer);
-
- /* Parse header section */
- if (data_len < hdr_len || osmo_mdns_rfc_header_decode(data, hdr_len, &hdr) != 0 || hdr.qr != 1)
- goto error;
- ret->id = hdr.id;
- data_len -= hdr_len;
- data += hdr_len;
-
- /* Parse resource records */
- INIT_LLIST_HEAD(&ret->records);
- while (data_len) {
- size_t record_len;
- struct osmo_mdns_rfc_record *rec;
- struct osmo_mdns_record* ret_record;
-
- rec = osmo_mdns_rfc_record_decode(ret, data, data_len, &record_len);
- if (!rec)
- goto error;
-
- /* Copy domain to ret */
- if (ret->domain) {
- if (strcmp(ret->domain, rec->domain) != 0) {
- LOGP(DMSLOOKUP, LOGL_ERROR, "domain mismatch in resource records ('%s' vs '%s')\n",
- ret->domain, rec->domain);
- goto error;
- }
- }
- else
- ret->domain = talloc_strdup(ret, rec->domain);
-
- /* Add simplified record to ret */
- ret_record = talloc_zero(ret, struct osmo_mdns_record);
- ret_record->type = rec->type;
- ret_record->length = rec->rdlength;
- ret_record->data = talloc_memdup(ret_record, rec->rdata, rec->rdlength);
- llist_add_tail(&ret_record->list, &ret->records);
-
- data += record_len;
- data_len -= record_len;
- talloc_free(rec);
- }
-
- /* Verify record count */
- if (llist_count(&ret->records) != hdr.ancount) {
- LOGP(DMSLOOKUP, LOGL_ERROR, "amount of parsed records (%i) doesn't match count in header (%i)\n",
- llist_count(&ret->records), hdr.ancount);
- goto error;
- }
-
- return ret;
-error:
- talloc_free(ret);
- return NULL;
-}
-
-/*! Get a TXT resource record, which stores a key=value string.
- * \returns allocated resource record on success, NULL on error.
- */
-static struct osmo_mdns_record *_osmo_mdns_record_txt_encode(void *ctx, const char *key, const char *value)
-{
- struct osmo_mdns_record *ret = talloc_zero(ctx, struct osmo_mdns_record);
- size_t len = strlen(key) + 1 + strlen(value);
-
- if (len > OSMO_MDNS_RFC_MAX_CHARACTER_STRING_LEN - 1)
- return NULL;
-
- /* redundant len is required, see RFC 1035 3.3.14 and 3.3. */
- ret->data = (uint8_t *)talloc_asprintf(ctx, "%c%s=%s", (char)len, key, value);
- if (!ret->data)
- return NULL;
- ret->type = OSMO_MDNS_RFC_RECORD_TYPE_TXT;
- ret->length = len + 1;
- return ret;
-}
-
-/*! Get a TXT resource record, which stores a key=value string, but build value from a format string.
- * \returns allocated resource record on success, NULL on error.
- */
-struct osmo_mdns_record *osmo_mdns_record_txt_keyval_encode(void *ctx, const char *key, const char *value_fmt, ...)
-{
- va_list ap;
- char *value = NULL;
- struct osmo_mdns_record *r;
-
- if (!value_fmt)
- return _osmo_mdns_record_txt_encode(ctx, key, "");
-
- va_start(ap, value_fmt);
- value = talloc_vasprintf(ctx, value_fmt, ap);
- if (!value)
- return NULL;
- va_end(ap);
- r = _osmo_mdns_record_txt_encode(ctx, key, value);
- talloc_free(value);
- return r;
-}
-
-/*! Decode a TXT resource record, which stores a key=value string.
- * \returns 0 on success, -EINVAL on error.
- */
-int osmo_mdns_record_txt_keyval_decode(const struct osmo_mdns_record *rec,
- char *key_buf, size_t key_size, char *value_buf, size_t value_size)
-{
- const char *key_value;
- const char *key_value_end;
- const char *sep;
- const char *value;
-
- if (rec->type != OSMO_MDNS_RFC_RECORD_TYPE_TXT)
- return -EINVAL;
-
- key_value = (const char *)rec->data;
- key_value_end = key_value + rec->length;
-
- /* Verify and then skip the redundant string length byte */
- if (*key_value != rec->length - 1)
- return -EINVAL;
- key_value++;
-
- if (key_value >= key_value_end)
- return -EINVAL;
-
- /* Find equals sign */
- sep = osmo_strnchr(key_value, key_value_end - key_value, '=');
- if (!sep)
- return -EINVAL;
-
- /* Parse key */
- osmo_print_n(key_buf, key_size, key_value, sep - key_value);
-
- /* Parse value */
- value = sep + 1;
- osmo_print_n(value_buf, value_size, value, key_value_end - value);
- return 0;
-}
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