From 4660e732139cde02f26459021dcc16a01360120b Mon Sep 17 00:00:00 2001
From: Brian Gix <bgix@qce.qualcomm.com>
Date: Fri, 5 Sep 2014 17:06:25 +0300
Subject: [PATCH] P2PS: Add Advertised Service Info into Probe Response frames
Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>
---
src/p2p/p2p.c | 10 +++
src/p2p/p2p_build.c | 150 ++++++++++++++++++++++++++++++++++++++++++++
src/p2p/p2p_i.h | 10 +++
3 files changed, 170 insertions(+)
diff --git a/src/p2p/p2p.c b/src/p2p/p2p.c
index ae4f5fc65..f339e2259 100644
--- a/src/p2p/p2p.c
+++ b/src/p2p/p2p.c
@@ -2116,6 +2116,9 @@ struct wpabuf * p2p_build_probe_resp_ies(struct p2p_data *p2p)
if (p2p->vendor_elem && p2p->vendor_elem[VENDOR_ELEM_PROBE_RESP_P2P])
extra += wpabuf_len(p2p->vendor_elem[VENDOR_ELEM_PROBE_RESP_P2P]);
+ if (p2p->query_count)
+ extra += MAX_SVC_ADV_IE_LEN;
+
buf = wpabuf_alloc(1000 + extra);
if (buf == NULL)
return NULL;
@@ -2150,6 +2153,12 @@ struct wpabuf * p2p_build_probe_resp_ies(struct p2p_data *p2p)
p2p_buf_add_device_info(buf, p2p, NULL);
p2p_buf_update_ie_hdr(buf, len);
+ if (p2p->query_count) {
+ p2p_buf_add_service_instance(buf, p2p, p2p->query_count,
+ p2p->query_hash,
+ p2p->p2ps_adv_list);
+ }
+
return buf;
}
@@ -2391,6 +2400,7 @@ p2p_probe_req_rx(struct p2p_data *p2p, const u8 *addr, const u8 *dst,
p2p_add_dev_from_probe_req(p2p, addr, ie, ie_len);
res = p2p_reply_probe(p2p, addr, dst, bssid, ie, ie_len);
+ p2p->query_count = 0;
if ((p2p->state == P2P_CONNECT || p2p->state == P2P_CONNECT_LISTEN) &&
p2p->go_neg_peer &&
diff --git a/src/p2p/p2p_build.c b/src/p2p/p2p_build.c
index 0789f9943..92c920662 100644
--- a/src/p2p/p2p_build.c
+++ b/src/p2p/p2p_build.c
@@ -404,6 +404,156 @@ void p2p_buf_add_advertisement_id(struct wpabuf *buf, u32 id, const u8 *mac)
}
+void p2p_buf_add_service_instance(struct wpabuf *buf, struct p2p_data *p2p,
+ u8 hash_count, const u8 *hash,
+ struct p2ps_advertisement *adv_list)
+{
+ struct p2ps_advertisement *adv;
+ struct wpabuf *tmp_buf;
+ u8 *tag_len = NULL, *ie_len = NULL;
+ size_t svc_len = 0, remaining = 0, total_len = 0;
+
+ if (!adv_list || !hash)
+ return;
+
+ /* Allocate temp buffer, allowing for overflow of 1 instance */
+ tmp_buf = wpabuf_alloc(MAX_SVC_ADV_IE_LEN + 256 + P2PS_HASH_LEN);
+ if (!tmp_buf)
+ return;
+
+ for (adv = adv_list; adv && total_len <= MAX_SVC_ADV_LEN;
+ adv = adv->next) {
+ u8 count = hash_count;
+ const u8 *test = hash;
+
+ while (count--) {
+ /* Check for wildcard */
+ if (os_memcmp(test, p2p->wild_card_hash,
+ P2PS_HASH_LEN) == 0) {
+ total_len = MAX_SVC_ADV_LEN + 1;
+ goto wild_hash;
+ }
+
+ if (os_memcmp(test, adv->hash, P2PS_HASH_LEN) == 0)
+ goto hash_match;
+
+ test += P2PS_HASH_LEN;
+ }
+
+ /* No matches found - Skip this Adv Instance */
+ continue;
+
+hash_match:
+ if (!tag_len) {
+ tag_len = p2p_buf_add_ie_hdr(tmp_buf);
+ remaining = 255 - 4;
+ if (!ie_len) {
+ wpabuf_put_u8(tmp_buf,
+ P2P_ATTR_ADVERTISED_SERVICE);
+ ie_len = wpabuf_put(tmp_buf, sizeof(u16));
+ remaining -= (sizeof(u8) + sizeof(u16));
+ }
+ }
+
+ svc_len = os_strlen(adv->svc_name);
+
+ if (7 + svc_len + total_len > MAX_SVC_ADV_LEN) {
+ /* Can't fit... return wildcard */
+ total_len = MAX_SVC_ADV_LEN + 1;
+ break;
+ }
+
+ if (remaining <= (sizeof(adv->id) +
+ sizeof(adv->config_methods))) {
+ size_t front = remaining;
+ size_t back = (sizeof(adv->id) +
+ sizeof(adv->config_methods)) - front;
+ u8 holder[sizeof(adv->id) +
+ sizeof(adv->config_methods)];
+
+ /* This works even if front or back == 0 */
+ WPA_PUT_LE32(holder, adv->id);
+ WPA_PUT_BE16(&holder[sizeof(adv->id)],
+ adv->config_methods);
+ wpabuf_put_data(tmp_buf, holder, front);
+ p2p_buf_update_ie_hdr(tmp_buf, tag_len);
+ tag_len = p2p_buf_add_ie_hdr(tmp_buf);
+ wpabuf_put_data(tmp_buf, &holder[front], back);
+ remaining = 255 - (sizeof(adv->id) +
+ sizeof(adv->config_methods)) - back;
+ } else {
+ wpabuf_put_le32(tmp_buf, adv->id);
+ wpabuf_put_be16(tmp_buf, adv->config_methods);
+ remaining -= (sizeof(adv->id) +
+ sizeof(adv->config_methods));
+ }
+
+ /* We are guaranteed at least one byte for svc_len */
+ wpabuf_put_u8(tmp_buf, svc_len);
+ remaining -= sizeof(u8);
+
+ if (remaining < svc_len) {
+ size_t front = remaining;
+ size_t back = svc_len - front;
+
+ wpabuf_put_data(tmp_buf, adv->svc_name, front);
+ p2p_buf_update_ie_hdr(tmp_buf, tag_len);
+ tag_len = p2p_buf_add_ie_hdr(tmp_buf);
+
+ /* In rare cases, we must split across 3 attributes */
+ if (back > 255 - 4) {
+ wpabuf_put_data(tmp_buf,
+ &adv->svc_name[front], 255 - 4);
+ back -= 255 - 4;
+ front += 255 - 4;
+ p2p_buf_update_ie_hdr(tmp_buf, tag_len);
+ tag_len = p2p_buf_add_ie_hdr(tmp_buf);
+ }
+
+ wpabuf_put_data(tmp_buf, &adv->svc_name[front], back);
+ remaining = 255 - 4 - back;
+ } else {
+ wpabuf_put_data(tmp_buf, adv->svc_name, svc_len);
+ remaining -= svc_len;
+ }
+
+ /* adv_id config_methods svc_string */
+ total_len += sizeof(u32) + sizeof(u16) + sizeof(u8) + svc_len;
+ }
+
+ if (tag_len)
+ p2p_buf_update_ie_hdr(tmp_buf, tag_len);
+
+ if (ie_len)
+ WPA_PUT_LE16(ie_len, (u16) total_len);
+
+wild_hash:
+ /* If all fit, return matching instances, otherwise the wildcard */
+ if (total_len <= MAX_SVC_ADV_LEN) {
+ wpabuf_put_buf(buf, tmp_buf);
+ } else {
+ char *wild_card = P2PS_WILD_HASH_STR;
+ u8 wild_len;
+
+ /* Insert wildcard instance */
+ tag_len = p2p_buf_add_ie_hdr(buf);
+ wpabuf_put_u8(buf, P2P_ATTR_ADVERTISED_SERVICE);
+ ie_len = wpabuf_put(buf, sizeof(u16));
+
+ wild_len = (u8) os_strlen(wild_card);
+ wpabuf_put_le32(buf, 0);
+ wpabuf_put_be16(buf, 0);
+ wpabuf_put_u8(buf, wild_len);
+ wpabuf_put_data(buf, wild_card, wild_len);
+
+ WPA_PUT_LE16(ie_len, 4 + 2 + 1 + wild_len);
+ p2p_buf_update_ie_hdr(buf, tag_len);
+ }
+
+ wpabuf_free(tmp_buf);
+}
+
+
void p2p_buf_add_session_id(struct wpabuf *buf, u32 id, const u8 *mac)
{
if (!buf || !mac)
diff --git a/src/p2p/p2p_i.h b/src/p2p/p2p_i.h
index bb9ff4dc8..91c6c5820 100644
--- a/src/p2p/p2p_i.h
+++ b/src/p2p/p2p_i.h
@@ -16,6 +16,13 @@
enum p2p_role_indication;
+/*
+ * To force Service Instances to fit within a single P2P Tag, MAX_SVC_ADV_LEN
+ * must equal 248 or less. Must have a minimum size of 19.
+ */
+#define MAX_SVC_ADV_LEN 600
+#define MAX_SVC_ADV_IE_LEN (9 + MAX_SVC_ADV_LEN + (5 * (MAX_SVC_ADV_LEN / 240)))
+
enum p2p_go_state {
UNKNOWN_GO,
LOCAL_GO,
@@ -736,6 +743,9 @@ void p2p_buf_add_service_hash(struct wpabuf *buf, struct p2p_data *p2p);
void p2p_buf_add_session_info(struct wpabuf *buf, const char *info);
void p2p_buf_add_connection_capability(struct wpabuf *buf, u8 connection_cap);
void p2p_buf_add_advertisement_id(struct wpabuf *buf, u32 id, const u8 *mac);
+void p2p_buf_add_service_instance(struct wpabuf *buf, struct p2p_data *p2p,
+ u8 count, const u8 *hash,
+ struct p2ps_advertisement *adv_list);
void p2p_buf_add_session_id(struct wpabuf *buf, u32 id, const u8 *mac);
void p2p_buf_add_feature_capability(struct wpabuf *buf, u16 len,
const u8 *mask);