netlink: Move more of the newlink/dellink parsing into shared code

src/drivers/driver_nl80211.c

@@ -353,21 +353,13 @@ static void wpa_driver_nl80211_event_link(struct wpa_driver_nl80211_data *drv,
 
 
 static int wpa_driver_nl80211_own_ifname(struct wpa_driver_nl80211_data *drv,
-					 struct nlmsghdr *h)
+					 u8 *buf, size_t len)
 {
-	struct ifinfomsg *ifi;
-	int attrlen, _nlmsg_len, rta_len;
+	int attrlen, rta_len;
 	struct rtattr *attr;
 
-	ifi = NLMSG_DATA(h);
-
-	_nlmsg_len = NLMSG_ALIGN(sizeof(struct ifinfomsg));
-
-	attrlen = NLMSG_PAYLOAD(h, sizeof(struct ifinfomsg));
-	if (attrlen < 0)
-		return 0;
-
-	attr = (struct rtattr *) (((char *) ifi) + _nlmsg_len);
+	attrlen = len;
+	attr = (struct rtattr *) buf;
 
 	rta_len = RTA_ALIGN(sizeof(struct rtattr));
 	while (RTA_OK(attr, attrlen)) {
@@ -386,12 +378,12 @@ static int wpa_driver_nl80211_own_ifname(struct wpa_driver_nl80211_data *drv,
 
 
 static int wpa_driver_nl80211_own_ifindex(struct wpa_driver_nl80211_data *drv,
-					  int ifindex, struct nlmsghdr *h)
+					  int ifindex, u8 *buf, size_t len)
 {
 	if (drv->ifindex == ifindex)
 		return 1;
 
-	if (drv->if_removed && wpa_driver_nl80211_own_ifname(drv, h)) {
+	if (drv->if_removed && wpa_driver_nl80211_own_ifname(drv, buf, len)) {
 		drv->ifindex = if_nametoindex(drv->ifname);
 		wpa_printf(MSG_DEBUG, "nl80211: Update ifindex for a removed "
 			   "interface");
@@ -403,20 +395,15 @@ static int wpa_driver_nl80211_own_ifindex(struct wpa_driver_nl80211_data *drv,
 }
 
 
-static void wpa_driver_nl80211_event_rtm_newlink(void *ctx, struct nlmsghdr *h,
-						 size_t len)
+static void wpa_driver_nl80211_event_rtm_newlink(void *ctx,
+						 struct ifinfomsg *ifi,
+						 u8 *buf, size_t len)
 {
 	struct wpa_driver_nl80211_data *drv = ctx;
-	struct ifinfomsg *ifi;
-	int attrlen, _nlmsg_len, rta_len;
-	struct rtattr * attr;
-
-	if (len < sizeof(*ifi))
-		return;
-
-	ifi = NLMSG_DATA(h);
+	int attrlen, rta_len;
+	struct rtattr *attr;
 
-	if (!wpa_driver_nl80211_own_ifindex(drv, ifi->ifi_index, h)) {
+	if (!wpa_driver_nl80211_own_ifindex(drv, ifi->ifi_index, buf, len)) {
 		wpa_printf(MSG_DEBUG, "Ignore event for foreign ifindex %d",
 			   ifi->ifi_index);
 		return;
@@ -441,14 +428,8 @@ static void wpa_driver_nl80211_event_rtm_newlink(void *ctx, struct nlmsghdr *h,
 		netlink_send_oper_ifla(drv->netlink, drv->ifindex,
 				       -1, IF_OPER_UP);
 
-	_nlmsg_len = NLMSG_ALIGN(sizeof(struct ifinfomsg));
-
-	attrlen = NLMSG_PAYLOAD(h, sizeof(struct ifinfomsg));
-	if (attrlen < 0)
-		return;
-
-	attr = (struct rtattr *) (((char *) ifi) + _nlmsg_len);
-
+	attrlen = len;
+	attr = (struct rtattr *) buf;
 	rta_len = RTA_ALIGN(sizeof(struct rtattr));
 	while (RTA_OK(attr, attrlen)) {
 		if (attr->rta_type == IFLA_IFNAME) {
@@ -462,26 +443,16 @@ static void wpa_driver_nl80211_event_rtm_newlink(void *ctx, struct nlmsghdr *h,
 }
 
 
-static void wpa_driver_nl80211_event_rtm_dellink(void *ctx, struct nlmsghdr *h,
-						 size_t len)
+static void wpa_driver_nl80211_event_rtm_dellink(void *ctx,
+						 struct ifinfomsg *ifi,
+						 u8 *buf, size_t len)
 {
 	struct wpa_driver_nl80211_data *drv = ctx;
-	struct ifinfomsg *ifi;
-	int attrlen, _nlmsg_len, rta_len;
-	struct rtattr * attr;
-
-	if (len < sizeof(*ifi))
-		return;
-
-	ifi = NLMSG_DATA(h);
-
-	_nlmsg_len = NLMSG_ALIGN(sizeof(struct ifinfomsg));
-
-	attrlen = NLMSG_PAYLOAD(h, sizeof(struct ifinfomsg));
-	if (attrlen < 0)
-		return;
+	int attrlen, rta_len;
+	struct rtattr *attr;
 
-	attr = (struct rtattr *) (((char *) ifi) + _nlmsg_len);
+	attrlen = len;
+	attr = (struct rtattr *) buf;
 
 	rta_len = RTA_ALIGN(sizeof(struct rtattr));
 	while (RTA_OK(attr, attrlen)) {

src/drivers/driver_wext.c

@@ -569,21 +569,13 @@ static void wpa_driver_wext_event_link(struct wpa_driver_wext_data *drv,
 
 
 static int wpa_driver_wext_own_ifname(struct wpa_driver_wext_data *drv,
-				      struct nlmsghdr *h)
+				      u8 *buf, size_t len)
 {
-	struct ifinfomsg *ifi;
-	int attrlen, nlmsg_len, rta_len;
+	int attrlen, rta_len;
 	struct rtattr *attr;
 
-	ifi = NLMSG_DATA(h);
-
-	nlmsg_len = NLMSG_ALIGN(sizeof(struct ifinfomsg));
-
-	attrlen = NLMSG_PAYLOAD(h, sizeof(struct ifinfomsg));
-	if (attrlen < 0)
-		return 0;
-
-	attr = (struct rtattr *) (((char *) ifi) + nlmsg_len);
+	attrlen = len;
+	attr = (struct rtattr *) buf;
 
 	rta_len = RTA_ALIGN(sizeof(struct rtattr));
 	while (RTA_OK(attr, attrlen)) {
@@ -602,12 +594,12 @@ static int wpa_driver_wext_own_ifname(struct wpa_driver_wext_data *drv,
 
 
 static int wpa_driver_wext_own_ifindex(struct wpa_driver_wext_data *drv,
-				       int ifindex, struct nlmsghdr *h)
+				       int ifindex, u8 *buf, size_t len)
 {
 	if (drv->ifindex == ifindex || drv->ifindex2 == ifindex)
 		return 1;
 
-	if (drv->if_removed && wpa_driver_wext_own_ifname(drv, h)) {
+	if (drv->if_removed && wpa_driver_wext_own_ifname(drv, buf, len)) {
 		drv->ifindex = if_nametoindex(drv->ifname);
 		wpa_printf(MSG_DEBUG, "WEXT: Update ifindex for a removed "
 			   "interface");
@@ -619,20 +611,14 @@ static int wpa_driver_wext_own_ifindex(struct wpa_driver_wext_data *drv,
 }
 
 
-static void wpa_driver_wext_event_rtm_newlink(void *ctx, struct nlmsghdr *h,
-					      size_t len)
+static void wpa_driver_wext_event_rtm_newlink(void *ctx, struct ifinfomsg *ifi,
+					      u8 *buf, size_t len)
 {
 	struct wpa_driver_wext_data *drv = ctx;
-	struct ifinfomsg *ifi;
-	int attrlen, nlmsg_len, rta_len;
+	int attrlen, rta_len;
 	struct rtattr *attr;
 
-	if (len < sizeof(*ifi))
-		return;
-
-	ifi = NLMSG_DATA(h);
-
-	if (!wpa_driver_wext_own_ifindex(drv, ifi->ifi_index, h)) {
+	if (!wpa_driver_wext_own_ifindex(drv, ifi->ifi_index, buf, len)) {
 		wpa_printf(MSG_DEBUG, "Ignore event for foreign ifindex %d",
 			   ifi->ifi_index);
 		return;
@@ -657,13 +643,8 @@ static void wpa_driver_wext_event_rtm_newlink(void *ctx, struct nlmsghdr *h,
 		netlink_send_oper_ifla(drv->netlink, drv->ifindex,
 				       -1, IF_OPER_UP);
 
-	nlmsg_len = NLMSG_ALIGN(sizeof(struct ifinfomsg));
-
-	attrlen = NLMSG_PAYLOAD(h, sizeof(struct ifinfomsg));
-	if (attrlen < 0)
-		return;
-
-	attr = (struct rtattr *) (((char *) ifi) + nlmsg_len);
+	attrlen = len;
+	attr = (struct rtattr *) buf;
 
 	rta_len = RTA_ALIGN(sizeof(struct rtattr));
 	while (RTA_OK(attr, attrlen)) {
@@ -681,26 +662,15 @@ static void wpa_driver_wext_event_rtm_newlink(void *ctx, struct nlmsghdr *h,
 }
 
 
-static void wpa_driver_wext_event_rtm_dellink(void *ctx, struct nlmsghdr *h,
-					      size_t len)
+static void wpa_driver_wext_event_rtm_dellink(void *ctx, struct ifinfomsg *ifi,
+					      u8 *buf, size_t len)
 {
 	struct wpa_driver_wext_data *drv = ctx;
-	struct ifinfomsg *ifi;
-	int attrlen, nlmsg_len, rta_len;
+	int attrlen, rta_len;
 	struct rtattr *attr;
 
-	if (len < sizeof(*ifi))
-		return;
-
-	ifi = NLMSG_DATA(h);
-
-	nlmsg_len = NLMSG_ALIGN(sizeof(struct ifinfomsg));
-
-	attrlen = NLMSG_PAYLOAD(h, sizeof(struct ifinfomsg));
-	if (attrlen < 0)
-		return;
-
-	attr = (struct rtattr *) (((char *) ifi) + nlmsg_len);
+	attrlen = len;
+	attr = (struct rtattr *) buf;
 
 	rta_len = RTA_ALIGN(sizeof(struct rtattr));
 	while (RTA_OK(attr, attrlen)) {

src/drivers/netlink.c

@@ -26,6 +26,19 @@ struct netlink_data {
 };
 
 
+static void netlink_receive_link(struct netlink_data *netlink,
+				 void (*cb)(void *ctx, struct ifinfomsg *ifi,
+					    u8 *buf, size_t len),
+				 struct nlmsghdr *h)
+{
+	if (cb == NULL || NLMSG_PAYLOAD(h, 0) < sizeof(struct ifinfomsg))
+		return;
+	cb(netlink->cfg->ctx, NLMSG_DATA(h),
+	   NLMSG_DATA(h) + NLMSG_ALIGN(sizeof(struct ifinfomsg)),
+	   NLMSG_PAYLOAD(h, sizeof(struct ifinfomsg)));
+}
+
+
 static void netlink_receive(int sock, void *eloop_ctx, void *sock_ctx)
 {
 	struct netlink_data *netlink = eloop_ctx;
@@ -49,20 +62,14 @@ try_again:
 
 	h = (struct nlmsghdr *) buf;
 	while (NLMSG_OK(h, left)) {
-		int plen;
-
-		plen = h->nlmsg_len - sizeof(*h);
-
 		switch (h->nlmsg_type) {
 		case RTM_NEWLINK:
-			if (netlink->cfg->newlink_cb)
-				netlink->cfg->newlink_cb(netlink->cfg->ctx,
-							 h, plen);
+			netlink_receive_link(netlink, netlink->cfg->newlink_cb,
+					     h);
 			break;
 		case RTM_DELLINK:
-			if (netlink->cfg->dellink_cb)
-				netlink->cfg->dellink_cb(netlink->cfg->ctx,
-							 h, plen);
+			netlink_receive_link(netlink, netlink->cfg->dellink_cb,
+					     h);
 			break;
 		}
 

src/drivers/netlink.h

@@ -19,8 +19,10 @@ struct netlink_data;
 
 struct netlink_config {
 	void *ctx;
-	void (*newlink_cb)(void *ctx, struct nlmsghdr *buf, size_t len);
-	void (*dellink_cb)(void *ctx, struct nlmsghdr *buf, size_t len);
+	void (*newlink_cb)(void *ctx, struct ifinfomsg *ifi, u8 *buf,
+			   size_t len);
+	void (*dellink_cb)(void *ctx, struct ifinfomsg *ifi, u8 *buf,
+			   size_t len);
 };
 
 struct netlink_data * netlink_init(struct netlink_config *cfg);