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Message-Id: <1340648900-6547-5-git-send-email-eldad@fogrefinery.com>
Date: Mon, 25 Jun 2012 20:28:16 +0200
From: Eldad Zack <eldad@...refinery.com>
To: netdev@...r.kernel.org
Cc: Eldad Zack <eldad@...refinery.com>
Subject: [PATCH 4/8] LLDP: PDU-handling routines
Routines for creation and parsing of LLPDUs.
Highlights:
* lldp_construct_pdu_list() constructs a list of TLVs
according to device and configuration.
* lldp_tlv_list_len() calculates the space needed to
send the above TLV list to the wire. Used when an sk_buff
is allocated.
* lldp_put_tlv_skb_list() writes the TLV list to the sk_buff.
Signed-off-by: Eldad Zack <eldad@...refinery.com>
---
net/lldp/lldpdu.c | 307 +++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 307 insertions(+)
create mode 100644 net/lldp/lldpdu.c
diff --git a/net/lldp/lldpdu.c b/net/lldp/lldpdu.c
new file mode 100644
index 0000000..e71ddd7
--- /dev/null
+++ b/net/lldp/lldpdu.c
@@ -0,0 +1,307 @@
+/* LLDP Link Layer Discovery Protocol impementation for Linux
+ * IEEE Std 802.1ab
+ *
+ * Author: Eldad Zack <eldad@...refinery.com>
+ *
+ * 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.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/if_ether.h>
+#include <linux/if_vlan.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/utsname.h>
+#include "lldp.h"
+
+const unsigned char oui_802_1[LLDP_OUI_LEN] = LLDP_OUI_802_1;
+const unsigned char oui_802_3[LLDP_OUI_LEN] = LLDP_OUI_802_3;
+
+int lldp_tlv_list_len(struct list_head *head)
+{
+ struct lldp_tlv *tlv;
+ int len = 0;
+
+ list_for_each_entry(tlv, head, lh)
+ len += tlv->entry_len;
+
+ return len;
+}
+
+void lldp_tlv_calc_entry_len(struct lldp_tlv *tlv)
+{
+ uint16_t elen;
+
+ BUG_ON(tlv == NULL);
+ BUG_ON(tlv->len > LLDP_LEN_MAX);
+
+ elen = 2; /* TLV Header */
+
+ if (tlv->subtype > 0)
+ elen += 1;
+
+ BUG_ON((tlv->oui != NULL) &&
+ (tlv->type != LLDP_TLV_ORGANIZATIONAL));
+ if (tlv->oui != NULL)
+ elen += LLDP_OUI_LEN;
+
+ elen += tlv->len; /* Actual data length */
+
+ tlv->entry_len = elen;
+}
+
+void __lldp_add_tlv_list(struct list_head *head, unsigned short type,
+ unsigned short len, unsigned char *data,
+ unsigned char subtype, const unsigned char *oui)
+{
+ struct lldp_tlv *tlv;
+
+ BUG_ON(len > LLDP_LEN_MAX);
+ BUG_ON(head == NULL);
+
+ tlv = kzalloc(sizeof(struct lldp_tlv), GFP_ATOMIC);
+
+ tlv->type = type;
+ tlv->len = len;
+
+ tlv->val = kmalloc(len, GFP_ATOMIC);
+ memcpy(tlv->val, data, len);
+
+ tlv->subtype = subtype;
+
+ if (type == LLDP_TLV_ORGANIZATIONAL) {
+ BUG_ON(oui == NULL);
+
+ tlv->oui = kmalloc(LLDP_OUI_LEN, GFP_ATOMIC);
+ memcpy(tlv->oui, oui, LLDP_OUI_LEN);
+ }
+
+ lldp_tlv_calc_entry_len(tlv);
+
+ list_add_tail(&(tlv->lh), head);
+}
+
+inline void lldp_add_tlv_list(struct list_head *head, unsigned short type,
+ unsigned short len, unsigned char *data)
+{
+ __lldp_add_tlv_list(head, type, len, data, 0, NULL);
+}
+
+inline void lldp_add_tlv_subtype_list(struct list_head *head,
+ unsigned short type,
+ unsigned short len, unsigned char *data,
+ unsigned char subtype)
+{
+ __lldp_add_tlv_list(head, type, len, data, subtype, NULL);
+}
+
+inline void lldp_add_oui_tlv_list(struct list_head *head,
+ const unsigned char *oui,
+ unsigned short len, unsigned char *data,
+ unsigned char subtype)
+{
+ __lldp_add_tlv_list(head, LLDP_TLV_ORGANIZATIONAL, len, data,
+ subtype, oui);
+}
+
+inline void lldp_add_tlv_chassis_id(struct list_head *head,
+ struct net_device *dev)
+{
+ lldp_add_tlv_subtype_list(head, LLDP_TLV_CHASSIS_ID, ETH_ALEN,
+ dev->dev_addr, LLDP_ST_CHID_MAC_ADDR);
+}
+
+inline void lldp_add_tlv_port_id(struct list_head *head, struct net_device *dev)
+{
+ lldp_add_tlv_subtype_list(head, LLDP_TLV_PORT_ID, strlen(dev->name),
+ dev->name, LLDP_ST_PORTID_IFNAME);
+}
+
+inline void lldp_add_tlv_ttl(struct list_head *head, struct net_device *dev,
+ bool is_shutdown)
+{
+ uint16_t ttl;
+
+ if (is_shutdown) {
+ ttl = 0;
+ } else {
+ ttl = htons(sysctl_lldp_transmit_interval *
+ sysctl_lldp_hold_multiplier);
+ }
+
+ lldp_add_tlv_list(head, LLDP_TLV_TIME_TO_LIVE, sizeof(ttl),
+ (unsigned char *) &ttl);
+}
+
+inline void lldp_add_tlv_vlan(struct list_head *head, struct net_device *dev)
+{
+#if IS_ENABLED(CONFIG_VLAN_8021Q)
+ if (dev->flags & IFF_802_1Q_VLAN) {
+ uint16_t vlan = htons(vlan_dev_vlan_id(dev));
+ /* Clause F.2.1: Value of 0 signifies that the system
+ * does not know the VLAN ID or doesn"t support it.
+ */
+ if (vlan != 0) {
+ lldp_add_oui_tlv_list(head, oui_802_1, sizeof(vlan),
+ (unsigned char *) &vlan,
+ LLDP_802_1_PORT_VLANID);
+ }
+ }
+#endif
+}
+
+inline void lldp_add_tlv_mtu(struct list_head *head, struct net_device *dev)
+{
+ uint16_t mtu;
+
+ mtu = htons(dev->mtu);
+ lldp_add_oui_tlv_list(head, oui_802_3, sizeof(mtu),
+ (unsigned char *) &mtu, LLDP_802_3_MTU);
+}
+
+inline void lldp_add_tlv_port_description(struct list_head *head,
+ struct net_device *dev)
+{
+ char *desc = dev->ifalias;
+ if (desc == NULL)
+ return;
+
+ lldp_add_tlv_list(head, LLDP_TLV_PORT_DESCRIPTION, strlen(desc), desc);
+}
+
+inline void lldp_add_tlv_system_name(struct list_head *head,
+ struct net_device *dev)
+{
+ char *name = utsname()->nodename;
+ if (name == NULL)
+ return;
+
+ lldp_add_tlv_list(head, LLDP_TLV_SYSTEM_NAME, strlen(name), name);
+}
+
+inline void lldp_add_tlv_system_description(struct list_head *head,
+ struct net_device *dev)
+{
+ char *desc = utsname()->sysname;
+ if (desc == NULL)
+ return;
+
+ lldp_add_tlv_list(head, LLDP_TLV_SYSTEM_DESCRIPTION,
+ strlen(desc), desc);
+}
+
+inline void lldp_add_tlv_system_capabilities(struct list_head *head,
+ struct net_device *dev)
+{
+ struct lldp_caps caps;
+
+ caps.sys = htons(LLDP_CAP_BRIDGE | LLDP_CAP_ROUTER);
+ caps.enabled = htons(LLDP_CAP_ROUTER);
+
+ lldp_add_tlv_list(head, LLDP_TLV_SYSTEM_CAPABILITIES,
+ sizeof(struct lldp_caps), (unsigned char *) &caps);
+}
+
+void lldp_tlv_construct_list(struct list_head *head, struct net_device *dev,
+ bool is_shutdown)
+{
+ BUG_ON(head == NULL);
+
+ /* Mandatory TLVs with strict order */
+ lldp_add_tlv_chassis_id(head, dev);
+ lldp_add_tlv_port_id(head, dev);
+ lldp_add_tlv_ttl(head, dev, is_shutdown);
+
+ /* Shutdown PDU is limited to mandatory TLVs only */
+ if (is_shutdown)
+ goto end;
+
+ /* Optional TLVs */
+ lldp_add_tlv_port_description(head, dev);
+ lldp_add_tlv_system_name(head, dev);
+ lldp_add_tlv_system_description(head, dev);
+ lldp_add_tlv_system_capabilities(head, dev);
+
+ /* Additional 802.1 and 802.3 private TLVs */
+ lldp_add_tlv_vlan(head, dev); /* Annex F.1 */
+ lldp_add_tlv_mtu(head, dev); /* Annex G.5 */
+
+end:
+ /* End TLV */
+ lldp_add_tlv_list(head, LLDP_TLV_END, 0, NULL);
+}
+
+void lldp_tlv_destruct(struct lldp_tlv *tlv)
+{
+ if (tlv->oui != NULL)
+ kfree(tlv->oui);
+
+ if (tlv->val != NULL)
+ kfree(tlv->val);
+}
+
+void lldp_tlv_destruct_list(struct list_head *head)
+{
+ struct lldp_tlv *tlv, *tmp;
+
+ if (head == NULL)
+ return;
+
+ if (list_empty(head))
+ return;
+
+ list_for_each_entry_safe(tlv, tmp, head, lh) {
+ list_del(&tlv->lh);
+ lldp_tlv_destruct(tlv);
+ kfree(tlv);
+ }
+}
+
+inline uint16_t tlv_hdr(struct lldp_tlv *tlv)
+{
+ int len = tlv->entry_len - LLDP_TLV_HDR_LEN;
+
+ BUG_ON(tlv == NULL);
+ BUG_ON(len < 0);
+
+ return htons(((tlv->type << LLDP_TYPE_SHIFT) & LLDP_TYPE_MASK) |
+ (len & LLDP_LEN_MASK));
+}
+
+void lldp_tlv_put_skb_list(struct sk_buff *skb, struct list_head *head)
+{
+ struct lldp_tlv *tlv;
+ struct list_head *p;
+ unsigned char *buf;
+ u16 hdr;
+
+ list_for_each(p, head) {
+ tlv = list_entry(p, struct lldp_tlv, lh);
+
+ hdr = tlv_hdr(tlv);
+ buf = skb_put(skb, sizeof(hdr));
+ memcpy(buf, &hdr, sizeof(hdr));
+
+ BUG_ON((tlv->oui != NULL) &&
+ (tlv->type != LLDP_TLV_ORGANIZATIONAL));
+ if (tlv->oui != NULL) {
+ buf = skb_put(skb, LLDP_OUI_LEN);
+ memcpy(buf, tlv->oui, LLDP_OUI_LEN);
+ }
+
+ if (tlv->subtype > 0) {
+ buf = skb_put(skb, sizeof(unsigned char));
+ *buf = tlv->subtype;
+ }
+
+ if (tlv->len > 0) {
+ BUG_ON(tlv->val == NULL);
+ buf = skb_put(skb, tlv->len);
+ memcpy(buf, tlv->val, tlv->len);
+ }
+ }
+}
--
1.7.10
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