Add tunnel key support to CAPWAP vport. Uses the optional WSI field in a CAPWAP header to store a 64bit key. It can also be used without keys, in which case it is backward compatible with the old code. Documentation about the WSI field format is in CAPWAP.txt.
Signed-off-by: Valient Gough <vgo...@pobox.com> --- datapath/CAPWAP.txt | 80 ++++++++++++++++++ datapath/Makefile.am | 2 +- datapath/Modules.mk | 4 + datapath/vport-capwap.c | 209 +++++++++++++++++++++++++++++++++++++--------- lib/netdev-vport.c | 12 +-- vswitchd/vswitch.xml | 26 ++++++ 6 files changed, 284 insertions(+), 49 deletions(-) create mode 100644 datapath/CAPWAP.txt diff --git a/datapath/CAPWAP.txt b/datapath/CAPWAP.txt new file mode 100644 index 0000000..151ad59 --- /dev/null +++ b/datapath/CAPWAP.txt @@ -0,0 +1,80 @@ + +References: +* http://www.rfc-editor.org/rfc/rfc5415.txt + + +The CAPWAP header layout is summarized as follows: + + + 0 1 2 3 + 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + |CAPWAP Preamble| HLEN | RID | WBID |T|F|L|W|M|K|Flags| + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Fragment ID | Frag Offset |Rsvd | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | (optional) Radio MAC Address | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | (optional) Wireless Specific Information | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Payload .... | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + +The spec defines an optional Wireless Specific Information field which can be +used to pass arbitrary data in the encapsulation layer: + + Wireless Specific Information: This optional field may be used to carry + per-packet information. This field is only present if the + 'W' bit is set. The WBID field in the CAPWAP Header is used to + identify the format of the WSI optional field. The HLEN field assumes + 4-byte alignment, and this field MUST be padded with zeroes (0x00) if it + is not 4-byte aligned. + + The Wireless-Specific Information field uses the following format: + + 0 1 2 3 + 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Length | Data... + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + Length: The 8-bit field contains the length of the data field, + with a maximum size of 255. + + Data: Wireless-specific information, defined by the wireless- + specific binding specified in the CAPWAP Header's WBID field. + + + WBID: A 5-bit field that is the wireless binding identifier. The + identifier will indicate the type of wireless packet associated + with the radio. The following values are defined: + + 0 - Reserved + 1 - IEEE 802.11 + 2 - Reserved + 3 - EPCGlobal [EPCGlobal] + + When Open vSwitch uses this field, it writes the value: + 30 - Open vSwitch data + + +Open vSwitch can make use of this field to pass additional packet routing +information. When needed, it sets the 'W' bit to indicates the WSI field is +added, and fills the field as follows: + + 0 1 2 3 + 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | WSI_LEN |K| Flags | Reserved | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | (optional) 64bit Tunnel Key | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + K - flag bit to identify presence of a 64bit tunnel key. + + +Adding WSI fields: Fields must be written and read in consitent order. New +fields may be added, but the existing fields always come first. + + + diff --git a/datapath/Makefile.am b/datapath/Makefile.am index e1bd3e6..fb1453c 100644 --- a/datapath/Makefile.am +++ b/datapath/Makefile.am @@ -3,7 +3,7 @@ if LINUX_ENABLED SUBDIRS += linux endif -EXTRA_DIST = $(dist_headers) $(dist_sources) +EXTRA_DIST = $(dist_headers) $(dist_sources) $(dist_extras) # Suppress warnings about GNU extensions in Modules.mk files. AUTOMAKE_OPTIONS = -Wno-portability diff --git a/datapath/Modules.mk b/datapath/Modules.mk index 587569f..894c41d 100644 --- a/datapath/Modules.mk +++ b/datapath/Modules.mk @@ -45,8 +45,12 @@ openvswitch_headers = \ vport-internal_dev.h \ vport-netdev.h +openvswitch_extras = \ + CAPWAP.txt + dist_sources = $(foreach module,$(dist_modules),$($(module)_sources)) dist_headers = $(foreach module,$(dist_modules),$($(module)_headers)) +dist_extras = $(foreach module,$(dist_modules),$($(module)_extras)) build_sources = $(foreach module,$(build_modules),$($(module)_sources)) build_headers = $(foreach module,$(build_modules),$($(module)_headers)) build_links = $(notdir $(build_sources)) diff --git a/datapath/vport-capwap.c b/datapath/vport-capwap.c index f0bb327..c338685 100644 --- a/datapath/vport-capwap.c +++ b/datapath/vport-capwap.c @@ -42,21 +42,62 @@ * statically create them and we can do very fast parsing by checking all 12 * fields in one go. */ -#define CAPWAP_BEGIN_HLEN __cpu_to_be32(0x00100000) -#define CAPWAP_BEGIN_WBID __cpu_to_be32(0x00000200) #define CAPWAP_BEGIN_FRAG __cpu_to_be32(0x00000080) -#define CAPWAP_BEGIN_LAST __cpu_to_be32(0x00000040) +#define CAPWAP_BEGIN_FRAG_LAST __cpu_to_be32(0x00000040) +#define CAPWAP_BEGIN_HLEN_2 __cpu_to_be32(0x00100000) +#define CAPWAP_BEGIN_HLEN_5 __cpu_to_be32(0x00280000) +#define CAPWAP_BEGIN_HLEN_MASK __cpu_to_be32(0x00F80000) + +/* Old capwap code is hard-coded to look for a WBID value of 2. + * When we insert WSI field, use WBID value of 30, which has been + * proposed for all "experimental" usage - users with no reserved WBID value + * of their own. +*/ +#define CAPWAP_WBID_30 __cpu_to_be32(0x00003C00) +#define CAPWAP_WBID_2 __cpu_to_be32(0x00000200) +#define CAPWAP_WBID_MASK __cpu_to_be32(0x00003E00) -#define NO_FRAG_HDR (CAPWAP_BEGIN_HLEN | CAPWAP_BEGIN_WBID) -#define FRAG_HDR (NO_FRAG_HDR | CAPWAP_BEGIN_FRAG) -#define FRAG_LAST_HDR (FRAG_HDR | CAPWAP_BEGIN_LAST) +/* + * CAPWAP allows an optional 'Wireless Specific Information' field, which is + * length prefixed and can contain any data. If keys are configured for the + * vport, then the key will be placed in the WSI field and recovered by the + * receiver. + */ +#define CAPWAP_FLAG_WSI __cpu_to_be32(0x00000020) + +#define FRAG_HDR (CAPWAP_BEGIN_FRAG) +#define FRAG_LAST_HDR (FRAG_HDR | CAPWAP_BEGIN_FRAG_LAST) + +/* Keyed packet, WBID 30, and length long enough to include WSI key */ +#define CAPWAP_KEYED (CAPWAP_WBID_30 | CAPWAP_FLAG_WSI | CAPWAP_BEGIN_HLEN_5) +/* A backward-compatible packet, WBID 2 and length of 2 words (no WSI fields) */ +#define CAPWAP_WO_WSI (CAPWAP_WBID_2 | CAPWAP_BEGIN_HLEN_2) +#define CAPWAP_COMPAT_MASK (CAPWAP_WBID_MASK | CAPWAP_BEGIN_HLEN_MASK) struct capwaphdr { __be32 begin; __be16 frag_id; + /* low 3 bits of frag_off are reserved */ __be16 frag_off; }; +/* + * We use the WSI field to hold additional tunnel data. + * The first eight bits store the size of the wsi data in bytes. + */ +struct capwaphdr_wsi { + u8 wsi_len; + u8 flags; + __be16 reserved_padding; +}; + +struct capwaphdr_wsi_key { + __be64 key; +}; + +/* Flag indicating a 64bit key is stored in WSI data field */ +#define CAPWAP_WSI_FLAG_KEY64 0x80 + static inline struct capwaphdr *capwap_hdr(const struct sk_buff *skb) { return (struct capwaphdr *)(udp_hdr(skb) + 1); @@ -70,7 +111,11 @@ static inline struct capwaphdr *capwap_hdr(const struct sk_buff *skb) */ #define FRAG_OFF_MASK (~0x7U) -#define CAPWAP_HLEN (sizeof(struct udphdr) + sizeof(struct capwaphdr)) +/* + * The minimum header length. The header may be longer if the optional + * WSI field is used. + */ +#define CAPWAP_MIN_HLEN (sizeof(struct udphdr) + sizeof(struct capwaphdr)) struct frag_match { __be32 saddr; @@ -89,7 +134,7 @@ struct frag_skb_cb { #define FRAG_CB(skb) ((struct frag_skb_cb *)(skb)->cb) static struct sk_buff *fragment(struct sk_buff *, const struct vport *, - struct dst_entry *); + struct dst_entry *dst, unsigned int hlen); static void defrag_init(void); static void defrag_exit(void); static struct sk_buff *defrag(struct sk_buff *, bool frag_last); @@ -117,18 +162,19 @@ static struct socket *capwap_rcv_socket; static int capwap_hdr_len(const struct tnl_mutable_config *mutable) { + int size = CAPWAP_MIN_HLEN; + /* CAPWAP has no checksums. */ if (mutable->flags & TNL_F_CSUM) return -EINVAL; - /* CAPWAP has no keys, so check that the configuration for keys is the - * default if no key-specific attributes are used. - */ - if ((mutable->flags & (TNL_F_IN_KEY_MATCH | TNL_F_OUT_KEY_ACTION)) != - (TNL_F_IN_KEY_MATCH | TNL_F_OUT_KEY_ACTION)) - return -EINVAL; + /* if keys are specified, then add WSI field */ + if (mutable->out_key || (mutable->flags & TNL_F_OUT_KEY_ACTION)) { + size += sizeof(struct capwaphdr_wsi) + + sizeof(struct capwaphdr_wsi_key); + } - return CAPWAP_HLEN; + return size; } static void capwap_build_header(const struct vport *vport, @@ -142,9 +188,31 @@ static void capwap_build_header(const struct vport *vport, udph->dest = htons(CAPWAP_DST_PORT); udph->check = 0; - cwh->begin = NO_FRAG_HDR; cwh->frag_id = 0; cwh->frag_off = 0; + + if (mutable->out_key || (mutable->flags & TNL_F_OUT_KEY_ACTION)) { + struct capwaphdr_wsi *wsi = (struct capwaphdr_wsi *)(cwh + 1); + + cwh->begin = CAPWAP_KEYED; + + /* -1 for wsi_len byte, not included in length as per spec */ + wsi->wsi_len = sizeof(struct capwaphdr_wsi) - 1 + + sizeof(struct capwaphdr_wsi_key); + wsi->flags = CAPWAP_WSI_FLAG_KEY64; + wsi->reserved_padding = 0; + + if (mutable->out_key) { + struct capwaphdr_wsi_key *opt = (struct capwaphdr_wsi_key *)(wsi + 1); + opt->key = mutable->out_key; + } else { + /* key left intentionally blank, to be filled in + by capwap_update_header */ + } + } else { + /* make packet readable by old capwap code */ + cwh->begin = CAPWAP_WO_WSI; + } } static struct sk_buff *capwap_update_header(const struct vport *vport, @@ -154,31 +222,88 @@ static struct sk_buff *capwap_update_header(const struct vport *vport, { struct udphdr *udph = udp_hdr(skb); + if (mutable->flags & TNL_F_OUT_KEY_ACTION) { + /* first field in WSI is key */ + struct capwaphdr *cwh = (struct capwaphdr *)(udph + 1); + struct capwaphdr_wsi *wsi = (struct capwaphdr_wsi *)(cwh + 1); + struct capwaphdr_wsi_key *opt = (struct capwaphdr_wsi_key *)(wsi + 1); + + opt->key = OVS_CB(skb)->tun_id; + } + udph->len = htons(skb->len - skb_transport_offset(skb)); - if (unlikely(skb->len - skb_network_offset(skb) > dst_mtu(dst))) - skb = fragment(skb, vport, dst); + if (unlikely(skb->len - skb_network_offset(skb) > dst_mtu(dst))) { + unsigned int hlen = skb_transport_offset(skb) + capwap_hdr_len(mutable); + skb = fragment(skb, vport, dst, hlen); + } return skb; } -static inline struct sk_buff *process_capwap_proto(struct sk_buff *skb) +static int process_capwap_wsi(struct sk_buff *skb, __be64 *key) { struct capwaphdr *cwh = capwap_hdr(skb); + struct capwaphdr_wsi *wsi; + int min_wsi_len = sizeof(struct capwaphdr_wsi); + int wsi_len; + + /* ensure we have at least a minimal wsi header */ + if (unlikely(!pskb_may_pull(skb, CAPWAP_MIN_HLEN + min_wsi_len + ETH_HLEN))) + return 1; + + /* read wsi header to find out how big it really is */ + wsi = (struct capwaphdr_wsi *)(cwh + 1); + /* +1 for length byte not included in wsi_len */ + wsi_len = 1 + (unsigned int)wsi->wsi_len; + if (unlikely(!pskb_may_pull(skb, CAPWAP_MIN_HLEN + wsi_len + ETH_HLEN))) + return 1; + + /* parse wsi field */ + if (wsi->flags & CAPWAP_WSI_FLAG_KEY64) { + struct capwaphdr_wsi_key *opt = (struct capwaphdr_wsi_key *)(wsi + 1); + if (unlikely(wsi_len <= sizeof(struct capwaphdr_wsi_key))) + return 1; + + *key = opt->key; + } - if (likely(cwh->begin == NO_FRAG_HDR)) - return skb; - else if (cwh->begin == FRAG_HDR) - return defrag(skb, false); - else if (cwh->begin == FRAG_LAST_HDR) - return defrag(skb, true); - else { - if (net_ratelimit()) - pr_warn("unparsable packet receive on capwap socket\n"); + return 0; +} - kfree_skb(skb); - return NULL; +static inline struct sk_buff *process_capwap_proto(struct sk_buff *skb, + __be64 *key) +{ + struct capwaphdr *cwh = capwap_hdr(skb); + int hdr_len = CAPWAP_MIN_HLEN; + + if ((cwh->begin & CAPWAP_WBID_MASK) != CAPWAP_WBID_30) { + if (unlikely((cwh->begin & CAPWAP_COMPAT_MASK) != CAPWAP_WO_WSI)) + goto error; + } else if (cwh->begin & CAPWAP_FLAG_WSI) { + struct capwaphdr_wsi *wsi = (struct capwaphdr_wsi *)(cwh + 1); + hdr_len += 1 + (unsigned int)wsi->wsi_len; + + if (unlikely(process_capwap_wsi(skb, key))) + goto error; } + + __skb_pull(skb, hdr_len); + skb_postpull_rcsum(skb, skb_transport_header(skb), hdr_len + ETH_HLEN); + + if (likely((cwh->begin & CAPWAP_BEGIN_FRAG) == 0)) { + return skb; + } else { + bool last_frag = (__force bool)(cwh->begin & CAPWAP_BEGIN_FRAG_LAST); + return defrag(skb, last_frag); + } + +error: + if (net_ratelimit()) + pr_warn("unparsable packet receive on capwap socket\n"); + + kfree_skb(skb); + return NULL; } /* Called with rcu_read_lock and BH disabled. */ @@ -187,25 +312,28 @@ static int capwap_rcv(struct sock *sk, struct sk_buff *skb) struct vport *vport; const struct tnl_mutable_config *mutable; struct iphdr *iph; + __be64 key = 0; - if (unlikely(!pskb_may_pull(skb, CAPWAP_HLEN + ETH_HLEN))) + if (unlikely(!pskb_may_pull(skb, CAPWAP_MIN_HLEN + ETH_HLEN))) goto error; - __skb_pull(skb, CAPWAP_HLEN); - skb_postpull_rcsum(skb, skb_transport_header(skb), CAPWAP_HLEN + ETH_HLEN); - - skb = process_capwap_proto(skb); + skb = process_capwap_proto(skb, &key); if (unlikely(!skb)) goto out; iph = ip_hdr(skb); - vport = tnl_find_port(iph->daddr, iph->saddr, 0, - TNL_T_PROTO_CAPWAP | TNL_T_KEY_EXACT, &mutable); + vport = tnl_find_port(iph->daddr, iph->saddr, key, + TNL_T_PROTO_CAPWAP | TNL_T_KEY_EITHER, &mutable); if (unlikely(!vport)) { icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); goto error; } + if (mutable->flags & TNL_F_IN_KEY_MATCH) + OVS_CB(skb)->tun_id = key; + else + OVS_CB(skb)->tun_id = 0; + tnl_rcv(vport, skb, iph->tos); goto out; @@ -290,10 +418,9 @@ static void copy_skb_metadata(struct sk_buff *from, struct sk_buff *to) } static struct sk_buff *fragment(struct sk_buff *skb, const struct vport *vport, - struct dst_entry *dst) + struct dst_entry *dst, unsigned int hlen) { struct tnl_vport *tnl_vport = tnl_vport_priv(vport); - unsigned int hlen = skb_transport_offset(skb) + CAPWAP_HLEN; unsigned int headroom; unsigned int max_frame_len = dst_mtu(dst) + skb_network_offset(skb); struct sk_buff *result = NULL, *list_cur = NULL; @@ -352,9 +479,9 @@ static struct sk_buff *fragment(struct sk_buff *skb, const struct vport *vport, cwh = capwap_hdr(skb2); if (remaining > frag_size) - cwh->begin = FRAG_HDR; + cwh->begin |= FRAG_HDR; else - cwh->begin = FRAG_LAST_HDR; + cwh->begin |= FRAG_LAST_HDR; cwh->frag_id = frag_id; cwh->frag_off = htons(offset); diff --git a/lib/netdev-vport.c b/lib/netdev-vport.c index b9c1bfe..9ca636d 100644 --- a/lib/netdev-vport.c +++ b/lib/netdev-vport.c @@ -668,9 +668,9 @@ parse_tunnel_config(const char *name, const char *type, || !strcmp(node->name, "private_key") || !strcmp(node->name, "use_ssl_cert"))) { /* Ignore options not used by the netdev. */ - } else if (is_gre && (!strcmp(node->name, "key") || - !strcmp(node->name, "in_key") || - !strcmp(node->name, "out_key"))) { + } else if (!strcmp(node->name, "key") || + !strcmp(node->name, "in_key") || + !strcmp(node->name, "out_key")) { /* Handled separately below. */ } else { VLOG_WARN("%s: unknown %s argument '%s'", name, type, node->name); @@ -700,10 +700,8 @@ parse_tunnel_config(const char *name, const char *type, } } - if (is_gre) { - set_key(args, "in_key", ODP_TUNNEL_ATTR_IN_KEY, options); - set_key(args, "out_key", ODP_TUNNEL_ATTR_OUT_KEY, options); - } + set_key(args, "in_key", ODP_TUNNEL_ATTR_IN_KEY, options); + set_key(args, "out_key", ODP_TUNNEL_ATTR_OUT_KEY, options); if (!daddr) { VLOG_ERR("%s: %s type requires valid 'remote_ip' argument", diff --git a/vswitchd/vswitch.xml b/vswitchd/vswitch.xml index 6199938..5f74e84 100644 --- a/vswitchd/vswitch.xml +++ b/vswitchd/vswitch.xml @@ -1056,6 +1056,32 @@ Default is the system default TTL.</dd> </dl> <dl> + <dt><code>in_key</code></dt> + <dd>Optional. The WSI key that received packets must contain. + It may either be a 64-bit number (no key and a key of 0 are + treated as equivalent) or the word <code>flow</code>. If + <code>flow</code> is specified then any key will be accepted + and the key will be placed in the <code>tun_id</code> field + for matching in the flow table. The ovs-ofctl manual page + contains additional information about matching fields in + OpenFlow flows. Default is no key.</dd> + </dl> + <dl> + <dt><code>out_key</code></dt> + <dd>Optional. The WSI key to be set on outgoing packets. It may + either be a 64-bit number or the word <code>flow</code>. If + <code>flow</code> is specified then the key may be set using + the <code>set_tunnel</code> Nicira OpenFlow vendor extension (0 + is used in the absence of an action). The ovs-ofctl manual + page contains additional information about the Nicira OpenFlow + vendor extensions. Default is no key.</dd> + </dl> + <dl> + <dt><code>key</code></dt> + <dd>Optional. Shorthand to set <code>in_key</code> and + <code>out_key</code> at the same time.</dd> + </dl> + <dl> <dt><code>df_inherit</code></dt> <dd>Optional. If enabled, the Don't Fragment bit will be copied from the inner IP headers (those of the encapsulated traffic) -- 1.7.6 _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
