2 * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013 Nicira, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at:
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
21 #include <sys/types.h>
22 #include <netinet/in.h>
27 #include "openvswitch/types.h"
34 /* Datapath packet metadata */
36 struct flow_tnl tunnel; /* Encapsulating tunnel parameters. */
37 uint32_t skb_priority; /* Packet priority for QoS. */
38 uint32_t pkt_mark; /* Packet mark. */
39 odp_port_t in_port; /* Input port. */
42 #define PKT_METADATA_INITIALIZER(PORT) \
43 (struct pkt_metadata){ { 0, 0, 0, 0, 0, 0}, 0, 0, (PORT) }
45 bool dpid_from_string(const char *s, uint64_t *dpidp);
47 #define ETH_ADDR_LEN 6
49 static const uint8_t eth_addr_broadcast[ETH_ADDR_LEN] OVS_UNUSED
50 = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
52 static const uint8_t eth_addr_stp[ETH_ADDR_LEN] OVS_UNUSED
53 = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x00 };
55 static const uint8_t eth_addr_lacp[ETH_ADDR_LEN] OVS_UNUSED
56 = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x02 };
58 static const uint8_t eth_addr_bfd[ETH_ADDR_LEN] OVS_UNUSED
59 = { 0x00, 0x23, 0x20, 0x00, 0x00, 0x01 };
61 static inline bool eth_addr_is_broadcast(const uint8_t ea[6])
63 return (ea[0] & ea[1] & ea[2] & ea[3] & ea[4] & ea[5]) == 0xff;
66 static inline bool eth_addr_is_multicast(const uint8_t ea[6])
70 static inline bool eth_addr_is_local(const uint8_t ea[6])
72 /* Local if it is either a locally administered address or a Nicira random
75 || (ea[0] == 0x00 && ea[1] == 0x23 && ea[2] == 0x20 && ea[3] & 0x80);
77 static inline bool eth_addr_is_zero(const uint8_t ea[6])
79 return !(ea[0] | ea[1] | ea[2] | ea[3] | ea[4] | ea[5]);
82 static inline int eth_mask_is_exact(const uint8_t ea[ETH_ADDR_LEN])
84 return (ea[0] & ea[1] & ea[2] & ea[3] & ea[4] & ea[5]) == 0xff;
87 static inline int eth_addr_compare_3way(const uint8_t a[ETH_ADDR_LEN],
88 const uint8_t b[ETH_ADDR_LEN])
90 return memcmp(a, b, ETH_ADDR_LEN);
92 static inline bool eth_addr_equals(const uint8_t a[ETH_ADDR_LEN],
93 const uint8_t b[ETH_ADDR_LEN])
95 return !eth_addr_compare_3way(a, b);
97 static inline bool eth_addr_equal_except(const uint8_t a[ETH_ADDR_LEN],
98 const uint8_t b[ETH_ADDR_LEN],
99 const uint8_t mask[ETH_ADDR_LEN])
101 return !(((a[0] ^ b[0]) & mask[0])
102 || ((a[1] ^ b[1]) & mask[1])
103 || ((a[2] ^ b[2]) & mask[2])
104 || ((a[3] ^ b[3]) & mask[3])
105 || ((a[4] ^ b[4]) & mask[4])
106 || ((a[5] ^ b[5]) & mask[5]));
108 static inline uint64_t eth_addr_to_uint64(const uint8_t ea[ETH_ADDR_LEN])
110 return (((uint64_t) ea[0] << 40)
111 | ((uint64_t) ea[1] << 32)
112 | ((uint64_t) ea[2] << 24)
113 | ((uint64_t) ea[3] << 16)
114 | ((uint64_t) ea[4] << 8)
117 static inline void eth_addr_from_uint64(uint64_t x, uint8_t ea[ETH_ADDR_LEN])
126 static inline void eth_addr_mark_random(uint8_t ea[ETH_ADDR_LEN])
128 ea[0] &= ~1; /* Unicast. */
129 ea[0] |= 2; /* Private. */
131 static inline void eth_addr_random(uint8_t ea[ETH_ADDR_LEN])
133 random_bytes(ea, ETH_ADDR_LEN);
134 eth_addr_mark_random(ea);
136 static inline void eth_addr_nicira_random(uint8_t ea[ETH_ADDR_LEN])
140 /* Set the OUI to the Nicira one. */
145 /* Set the top bit to indicate random Nicira address. */
149 bool eth_addr_is_reserved(const uint8_t ea[ETH_ADDR_LEN]);
150 bool eth_addr_from_string(const char *, uint8_t ea[ETH_ADDR_LEN]);
152 void compose_rarp(struct ofpbuf *, const uint8_t eth_src[ETH_ADDR_LEN]);
154 void eth_push_vlan(struct ofpbuf *, ovs_be16 tci);
155 void eth_pop_vlan(struct ofpbuf *);
157 void set_ethertype(struct ofpbuf *packet, ovs_be16 eth_type);
159 const char *eth_from_hex(const char *hex, struct ofpbuf **packetp);
160 void eth_format_masked(const uint8_t eth[ETH_ADDR_LEN],
161 const uint8_t mask[ETH_ADDR_LEN], struct ds *s);
162 void eth_addr_bitand(const uint8_t src[ETH_ADDR_LEN],
163 const uint8_t mask[ETH_ADDR_LEN],
164 uint8_t dst[ETH_ADDR_LEN]);
166 void set_mpls_lse(struct ofpbuf *, ovs_be32 label);
167 void push_mpls(struct ofpbuf *packet, ovs_be16 ethtype, ovs_be32 lse);
168 void pop_mpls(struct ofpbuf *, ovs_be16 ethtype);
170 void set_mpls_lse_ttl(ovs_be32 *lse, uint8_t ttl);
171 void set_mpls_lse_tc(ovs_be32 *lse, uint8_t tc);
172 void set_mpls_lse_label(ovs_be32 *lse, ovs_be32 label);
173 void set_mpls_lse_bos(ovs_be32 *lse, uint8_t bos);
174 ovs_be32 set_mpls_lse_values(uint8_t ttl, uint8_t tc, uint8_t bos,
179 * uint8_t mac[ETH_ADDR_LEN];
181 * printf("The Ethernet address is "ETH_ADDR_FMT"\n", ETH_ADDR_ARGS(mac));
184 #define ETH_ADDR_FMT \
185 "%02"PRIx8":%02"PRIx8":%02"PRIx8":%02"PRIx8":%02"PRIx8":%02"PRIx8
186 #define ETH_ADDR_ARGS(ea) \
187 (ea)[0], (ea)[1], (ea)[2], (ea)[3], (ea)[4], (ea)[5]
191 * char *string = "1 00:11:22:33:44:55 2";
192 * uint8_t mac[ETH_ADDR_LEN];
195 * if (ovs_scan(string, "%d"ETH_ADDR_SCAN_FMT"%d",
196 * &a, ETH_ADDR_SCAN_ARGS(mac), &b)) {
200 #define ETH_ADDR_SCAN_FMT "%"SCNx8":%"SCNx8":%"SCNx8":%"SCNx8":%"SCNx8":%"SCNx8
201 #define ETH_ADDR_SCAN_ARGS(ea) \
202 &(ea)[0], &(ea)[1], &(ea)[2], &(ea)[3], &(ea)[4], &(ea)[5]
204 #define ETH_TYPE_IP 0x0800
205 #define ETH_TYPE_ARP 0x0806
206 #define ETH_TYPE_VLAN_8021Q 0x8100
207 #define ETH_TYPE_VLAN ETH_TYPE_VLAN_8021Q
208 #define ETH_TYPE_VLAN_8021AD 0x88a8
209 #define ETH_TYPE_IPV6 0x86dd
210 #define ETH_TYPE_LACP 0x8809
211 #define ETH_TYPE_RARP 0x8035
212 #define ETH_TYPE_MPLS 0x8847
213 #define ETH_TYPE_MPLS_MCAST 0x8848
215 static inline bool eth_type_mpls(ovs_be16 eth_type)
217 return eth_type == htons(ETH_TYPE_MPLS) ||
218 eth_type == htons(ETH_TYPE_MPLS_MCAST);
221 /* Minimum value for an Ethernet type. Values below this are IEEE 802.2 frame
223 #define ETH_TYPE_MIN 0x600
225 #define ETH_HEADER_LEN 14
226 #define ETH_PAYLOAD_MIN 46
227 #define ETH_PAYLOAD_MAX 1500
228 #define ETH_TOTAL_MIN (ETH_HEADER_LEN + ETH_PAYLOAD_MIN)
229 #define ETH_TOTAL_MAX (ETH_HEADER_LEN + ETH_PAYLOAD_MAX)
230 #define ETH_VLAN_TOTAL_MAX (ETH_HEADER_LEN + VLAN_HEADER_LEN + ETH_PAYLOAD_MAX)
233 uint8_t eth_dst[ETH_ADDR_LEN];
234 uint8_t eth_src[ETH_ADDR_LEN];
237 BUILD_ASSERT_DECL(ETH_HEADER_LEN == sizeof(struct eth_header));
239 #define LLC_DSAP_SNAP 0xaa
240 #define LLC_SSAP_SNAP 0xaa
241 #define LLC_CNTL_SNAP 3
243 #define LLC_HEADER_LEN 3
250 BUILD_ASSERT_DECL(LLC_HEADER_LEN == sizeof(struct llc_header));
252 #define SNAP_ORG_ETHERNET "\0\0" /* The compiler adds a null byte, so
253 sizeof(SNAP_ORG_ETHERNET) == 3. */
254 #define SNAP_HEADER_LEN 5
260 BUILD_ASSERT_DECL(SNAP_HEADER_LEN == sizeof(struct snap_header));
262 #define LLC_SNAP_HEADER_LEN (LLC_HEADER_LEN + SNAP_HEADER_LEN)
264 struct llc_snap_header {
265 struct llc_header llc;
266 struct snap_header snap;
268 BUILD_ASSERT_DECL(LLC_SNAP_HEADER_LEN == sizeof(struct llc_snap_header));
270 #define VLAN_VID_MASK 0x0fff
271 #define VLAN_VID_SHIFT 0
273 #define VLAN_PCP_MASK 0xe000
274 #define VLAN_PCP_SHIFT 13
276 #define VLAN_CFI 0x1000
277 #define VLAN_CFI_SHIFT 12
279 /* Given the vlan_tci field from an 802.1Q header, in network byte order,
280 * returns the VLAN ID in host byte order. */
281 static inline uint16_t
282 vlan_tci_to_vid(ovs_be16 vlan_tci)
284 return (ntohs(vlan_tci) & VLAN_VID_MASK) >> VLAN_VID_SHIFT;
287 /* Given the vlan_tci field from an 802.1Q header, in network byte order,
288 * returns the priority code point (PCP) in host byte order. */
290 vlan_tci_to_pcp(ovs_be16 vlan_tci)
292 return (ntohs(vlan_tci) & VLAN_PCP_MASK) >> VLAN_PCP_SHIFT;
295 /* Given the vlan_tci field from an 802.1Q header, in network byte order,
296 * returns the Canonical Format Indicator (CFI). */
298 vlan_tci_to_cfi(ovs_be16 vlan_tci)
300 return (vlan_tci & htons(VLAN_CFI)) != 0;
303 #define VLAN_HEADER_LEN 4
305 ovs_be16 vlan_tci; /* Lowest 12 bits are VLAN ID. */
306 ovs_be16 vlan_next_type;
308 BUILD_ASSERT_DECL(VLAN_HEADER_LEN == sizeof(struct vlan_header));
310 #define VLAN_ETH_HEADER_LEN (ETH_HEADER_LEN + VLAN_HEADER_LEN)
312 struct vlan_eth_header {
313 uint8_t veth_dst[ETH_ADDR_LEN];
314 uint8_t veth_src[ETH_ADDR_LEN];
315 ovs_be16 veth_type; /* Always htons(ETH_TYPE_VLAN). */
316 ovs_be16 veth_tci; /* Lowest 12 bits are VLAN ID. */
317 ovs_be16 veth_next_type;
319 BUILD_ASSERT_DECL(VLAN_ETH_HEADER_LEN == sizeof(struct vlan_eth_header));
321 /* MPLS related definitions */
322 #define MPLS_TTL_MASK 0x000000ff
323 #define MPLS_TTL_SHIFT 0
325 #define MPLS_BOS_MASK 0x00000100
326 #define MPLS_BOS_SHIFT 8
328 #define MPLS_TC_MASK 0x00000e00
329 #define MPLS_TC_SHIFT 9
331 #define MPLS_LABEL_MASK 0xfffff000
332 #define MPLS_LABEL_SHIFT 12
339 BUILD_ASSERT_DECL(MPLS_HLEN == sizeof(struct mpls_hdr));
341 /* Given a mpls label stack entry in network byte order
342 * return mpls label in host byte order */
343 static inline uint32_t
344 mpls_lse_to_label(ovs_be32 mpls_lse)
346 return (ntohl(mpls_lse) & MPLS_LABEL_MASK) >> MPLS_LABEL_SHIFT;
349 /* Given a mpls label stack entry in network byte order
351 static inline uint8_t
352 mpls_lse_to_tc(ovs_be32 mpls_lse)
354 return (ntohl(mpls_lse) & MPLS_TC_MASK) >> MPLS_TC_SHIFT;
357 /* Given a mpls label stack entry in network byte order
359 static inline uint8_t
360 mpls_lse_to_ttl(ovs_be32 mpls_lse)
362 return (ntohl(mpls_lse) & MPLS_TTL_MASK) >> MPLS_TTL_SHIFT;
365 /* Set TTL in mpls lse. */
367 flow_set_mpls_lse_ttl(ovs_be32 *mpls_lse, uint8_t ttl)
369 *mpls_lse &= ~htonl(MPLS_TTL_MASK);
370 *mpls_lse |= htonl(ttl << MPLS_TTL_SHIFT);
373 /* Given a mpls label stack entry in network byte order
374 * return mpls BoS bit */
375 static inline uint8_t
376 mpls_lse_to_bos(ovs_be32 mpls_lse)
378 return (mpls_lse & htonl(MPLS_BOS_MASK)) != 0;
381 #define IP_FMT "%"PRIu32".%"PRIu32".%"PRIu32".%"PRIu32
382 #define IP_ARGS(ip) \
384 (ntohl(ip) >> 16) & 0xff, \
385 (ntohl(ip) >> 8) & 0xff, \
390 * char *string = "1 33.44.55.66 2";
394 * if (ovs_scan(string, "%d"IP_SCAN_FMT"%d", &a, IP_SCAN_ARGS(&ip), &b)) {
398 #define IP_SCAN_FMT "%"SCNu8".%"SCNu8".%"SCNu8".%"SCNu8
399 #define IP_SCAN_ARGS(ip) \
400 ((void) (ovs_be32) *(ip), &((uint8_t *) ip)[0]), \
401 &((uint8_t *) ip)[1], \
402 &((uint8_t *) ip)[2], \
405 /* Returns true if 'netmask' is a CIDR netmask, that is, if it consists of N
406 * high-order 1-bits and 32-N low-order 0-bits. */
408 ip_is_cidr(ovs_be32 netmask)
410 uint32_t x = ~ntohl(netmask);
411 return !(x & (x + 1));
414 ip_is_multicast(ovs_be32 ip)
416 return (ip & htonl(0xf0000000)) == htonl(0xe0000000);
418 int ip_count_cidr_bits(ovs_be32 netmask);
419 void ip_format_masked(ovs_be32 ip, ovs_be32 mask, struct ds *);
421 #define IP_VER(ip_ihl_ver) ((ip_ihl_ver) >> 4)
422 #define IP_IHL(ip_ihl_ver) ((ip_ihl_ver) & 15)
423 #define IP_IHL_VER(ihl, ver) (((ver) << 4) | (ihl))
426 #define IPPROTO_SCTP 132
430 #define IP_ECN_NOT_ECT 0x0
431 #define IP_ECN_ECT_1 0x01
432 #define IP_ECN_ECT_0 0x02
433 #define IP_ECN_CE 0x03
434 #define IP_ECN_MASK 0x03
435 #define IP_DSCP_MASK 0xfc
439 #define IP_DONT_FRAGMENT 0x4000 /* Don't fragment. */
440 #define IP_MORE_FRAGMENTS 0x2000 /* More fragments. */
441 #define IP_FRAG_OFF_MASK 0x1fff /* Fragment offset. */
442 #define IP_IS_FRAGMENT(ip_frag_off) \
443 ((ip_frag_off) & htons(IP_MORE_FRAGMENTS | IP_FRAG_OFF_MASK))
445 #define IP_HEADER_LEN 20
451 ovs_be16 ip_frag_off;
455 ovs_16aligned_be32 ip_src;
456 ovs_16aligned_be32 ip_dst;
458 BUILD_ASSERT_DECL(IP_HEADER_LEN == sizeof(struct ip_header));
460 #define ICMP_HEADER_LEN 8
474 ovs_16aligned_be32 gateway;
476 uint8_t icmp_data[0];
478 BUILD_ASSERT_DECL(ICMP_HEADER_LEN == sizeof(struct icmp_header));
480 #define SCTP_HEADER_LEN 12
487 BUILD_ASSERT_DECL(SCTP_HEADER_LEN == sizeof(struct sctp_header));
489 #define UDP_HEADER_LEN 8
496 BUILD_ASSERT_DECL(UDP_HEADER_LEN == sizeof(struct udp_header));
498 #define TCP_FIN 0x001
499 #define TCP_SYN 0x002
500 #define TCP_RST 0x004
501 #define TCP_PSH 0x008
502 #define TCP_ACK 0x010
503 #define TCP_URG 0x020
504 #define TCP_ECE 0x040
505 #define TCP_CWR 0x080
508 #define TCP_CTL(flags, offset) (htons((flags) | ((offset) << 12)))
509 #define TCP_FLAGS(tcp_ctl) (ntohs(tcp_ctl) & 0x0fff)
510 #define TCP_OFFSET(tcp_ctl) (ntohs(tcp_ctl) >> 12)
512 #define TCP_HEADER_LEN 20
516 ovs_16aligned_be32 tcp_seq;
517 ovs_16aligned_be32 tcp_ack;
523 BUILD_ASSERT_DECL(TCP_HEADER_LEN == sizeof(struct tcp_header));
525 #define ARP_HRD_ETHERNET 1
526 #define ARP_PRO_IP 0x0800
527 #define ARP_OP_REQUEST 1
528 #define ARP_OP_REPLY 2
529 #define ARP_OP_RARP 3
531 #define ARP_ETH_HEADER_LEN 28
532 struct arp_eth_header {
533 /* Generic members. */
534 ovs_be16 ar_hrd; /* Hardware type. */
535 ovs_be16 ar_pro; /* Protocol type. */
536 uint8_t ar_hln; /* Hardware address length. */
537 uint8_t ar_pln; /* Protocol address length. */
538 ovs_be16 ar_op; /* Opcode. */
540 /* Ethernet+IPv4 specific members. */
541 uint8_t ar_sha[ETH_ADDR_LEN]; /* Sender hardware address. */
542 ovs_16aligned_be32 ar_spa; /* Sender protocol address. */
543 uint8_t ar_tha[ETH_ADDR_LEN]; /* Target hardware address. */
544 ovs_16aligned_be32 ar_tpa; /* Target protocol address. */
546 BUILD_ASSERT_DECL(ARP_ETH_HEADER_LEN == sizeof(struct arp_eth_header));
548 /* Like struct in6_addr, but whereas that struct requires 32-bit alignment on
549 * most implementations, this one only requires 16-bit alignment. */
550 union ovs_16aligned_in6_addr {
552 ovs_16aligned_be32 be32[4];
555 /* Like struct in6_hdr, but whereas that struct requires 32-bit alignment, this
556 * one only requires 16-bit alignment. */
557 struct ovs_16aligned_ip6_hdr {
559 struct ovs_16aligned_ip6_hdrctl {
560 ovs_16aligned_be32 ip6_un1_flow;
561 ovs_be16 ip6_un1_plen;
563 uint8_t ip6_un1_hlim;
567 union ovs_16aligned_in6_addr ip6_src;
568 union ovs_16aligned_in6_addr ip6_dst;
571 /* Like struct in6_frag, but whereas that struct requires 32-bit alignment,
572 * this one only requires 16-bit alignment. */
573 struct ovs_16aligned_ip6_frag {
575 uint8_t ip6f_reserved;
577 ovs_16aligned_be32 ip6f_ident;
580 /* The IPv6 flow label is in the lower 20 bits of the first 32-bit word. */
581 #define IPV6_LABEL_MASK 0x000fffff
585 * char *string = "1 ::1 2";
586 * char ipv6_s[IPV6_SCAN_LEN + 1];
587 * struct in6_addr ipv6;
589 * if (ovs_scan(string, "%d"IPV6_SCAN_FMT"%d", &a, ipv6_s, &b)
590 * && inet_pton(AF_INET6, ipv6_s, &ipv6) == 1) {
594 #define IPV6_SCAN_FMT "%46[0123456789abcdefABCDEF:.]"
595 #define IPV6_SCAN_LEN 46
597 extern const struct in6_addr in6addr_exact;
598 #define IN6ADDR_EXACT_INIT { { { 0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff, \
599 0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff } } }
601 static inline bool ipv6_addr_equals(const struct in6_addr *a,
602 const struct in6_addr *b)
604 #ifdef IN6_ARE_ADDR_EQUAL
605 return IN6_ARE_ADDR_EQUAL(a, b);
607 return !memcmp(a, b, sizeof(*a));
611 static inline bool ipv6_mask_is_any(const struct in6_addr *mask) {
612 return ipv6_addr_equals(mask, &in6addr_any);
615 static inline bool ipv6_mask_is_exact(const struct in6_addr *mask) {
616 return ipv6_addr_equals(mask, &in6addr_exact);
619 static inline bool dl_type_is_ip_any(ovs_be16 dl_type)
621 return dl_type == htons(ETH_TYPE_IP)
622 || dl_type == htons(ETH_TYPE_IPV6);
625 static inline bool is_ip_any(const struct flow *flow)
627 return dl_type_is_ip_any(flow->dl_type);
630 void format_ipv6_addr(char *addr_str, const struct in6_addr *addr);
631 void print_ipv6_addr(struct ds *string, const struct in6_addr *addr);
632 void print_ipv6_masked(struct ds *string, const struct in6_addr *addr,
633 const struct in6_addr *mask);
634 struct in6_addr ipv6_addr_bitand(const struct in6_addr *src,
635 const struct in6_addr *mask);
636 struct in6_addr ipv6_create_mask(int mask);
637 int ipv6_count_cidr_bits(const struct in6_addr *netmask);
638 bool ipv6_is_cidr(const struct in6_addr *netmask);
640 void *eth_compose(struct ofpbuf *, const uint8_t eth_dst[ETH_ADDR_LEN],
641 const uint8_t eth_src[ETH_ADDR_LEN], uint16_t eth_type,
643 void *snap_compose(struct ofpbuf *, const uint8_t eth_dst[ETH_ADDR_LEN],
644 const uint8_t eth_src[ETH_ADDR_LEN],
645 unsigned int oui, uint16_t snap_type, size_t size);
646 void packet_set_ipv4(struct ofpbuf *, ovs_be32 src, ovs_be32 dst, uint8_t tos,
648 void packet_set_ipv6(struct ofpbuf *, uint8_t proto, const ovs_be32 src[4],
649 const ovs_be32 dst[4], uint8_t tc,
650 ovs_be32 fl, uint8_t hlmit);
651 void packet_set_tcp_port(struct ofpbuf *, ovs_be16 src, ovs_be16 dst);
652 void packet_set_udp_port(struct ofpbuf *, ovs_be16 src, ovs_be16 dst);
653 void packet_set_sctp_port(struct ofpbuf *, ovs_be16 src, ovs_be16 dst);
655 uint16_t packet_get_tcp_flags(const struct ofpbuf *, const struct flow *);
656 void packet_format_tcp_flags(struct ds *, uint16_t);
657 const char *packet_tcp_flag_to_string(uint32_t flag);
659 #endif /* packets.h */