From a3814acf847096de45242908924b5bee4b253f93 Mon Sep 17 00:00:00 2001 From: Sam Leffler Date: Thu, 14 Nov 2002 23:43:16 +0000 Subject: [PATCH] o eliminate separate callback interface for h/w tagged input packets; instead drivers "tag packets" with an m_tag and the input packet handling recognizes such packets and does the right thing o track the number of active vlans on an interface; this lets lots of places only do vlan-specific processing when needed o track changes to ether_ifdetach/ether_ifattach o track bpf changes o eliminate the use of M_PROTO1 for communicating to drivers about tagged packets o eliminate the use of IFF_LINK0 for drivers communicating to the vlan code that they support h/w tagging; replaced by explicit interface capabilities o add ifnet capabilities for h/w tagging and support of "large mtu's" o use new interface capabilities to auto-configure use of large mtu's and h/w tagging o add support for proper handling of promiscuous mode o document driver/vlan communication conventions Reviewed by: many Approved by: re --- sys/net/if_vlan.c | 385 ++++++++++++++++++++++++++---------------- sys/net/if_vlan_var.h | 79 ++++++--- 2 files changed, 301 insertions(+), 163 deletions(-) diff --git a/sys/net/if_vlan.c b/sys/net/if_vlan.c index 33924ac05b9f..1850e8d94653 100644 --- a/sys/net/if_vlan.c +++ b/sys/net/if_vlan.c @@ -39,19 +39,6 @@ * ether_output() left on our output queue when it calls * if_start(), rewrite them for use by the real outgoing interface, * and ask it to send them. - * - * - * XXX It's incorrect to assume that we must always kludge up - * headers on the physical device's behalf: some devices support - * VLAN tag insertion and extraction in firmware. For these cases, - * one can change the behavior of the vlan interface by setting - * the LINK0 flag on it (that is setting the vlan interface's LINK0 - * flag, _not_ the parent's LINK0 flag; we try to leave the parent - * alone). If the interface has the LINK0 flag set, then it will - * not modify the ethernet header on output, because the parent - * can do that for itself. On input, the parent can call vlan_input_tag() - * directly in order to supply us with an incoming mbuf and the vlan - * tag value that goes with it. */ #include "opt_inet.h" @@ -82,6 +69,34 @@ #define VLANNAME "vlan" +struct vlan_mc_entry { + struct ether_addr mc_addr; + SLIST_ENTRY(vlan_mc_entry) mc_entries; +}; + +struct ifvlan { + struct arpcom ifv_ac; /* make this an interface */ + struct ifnet *ifv_p; /* parent inteface of this vlan */ + struct ifv_linkmib { + int ifvm_parent; + int ifvm_encaplen; /* encapsulation length */ + int ifvm_mtufudge; /* MTU fudged by this much */ + int ifvm_mintu; /* min transmission unit */ + u_int16_t ifvm_proto; /* encapsulation ethertype */ + u_int16_t ifvm_tag; /* tag to apply on packets leaving if */ + } ifv_mib; + SLIST_HEAD(__vlan_mchead, vlan_mc_entry) vlan_mc_listhead; + LIST_ENTRY(ifvlan) ifv_list; + int ifv_flags; +}; +#define ifv_if ifv_ac.ac_if +#define ifv_tag ifv_mib.ifvm_tag +#define ifv_encaplen ifv_mib.ifvm_encaplen +#define ifv_mtufudge ifv_mib.ifvm_mtufudge +#define ifv_mintu ifv_mib.ifvm_mintu + +#define IFVF_PROMISC 0x01 /* promiscuous mode enabled */ + SYSCTL_DECL(_net_link); SYSCTL_NODE(_net_link, IFT_L2VLAN, vlan, CTLFLAG_RW, 0, "IEEE 802.1Q VLAN"); SYSCTL_NODE(_net_link_vlan, PF_LINK, link, CTLFLAG_RW, 0, "for consistency"); @@ -93,9 +108,7 @@ static int vlan_clone_create(struct if_clone *, int); static void vlan_clone_destroy(struct ifnet *); static void vlan_start(struct ifnet *ifp); static void vlan_ifinit(void *foo); -static int vlan_input(struct ether_header *eh, struct mbuf *m); -static int vlan_input_tag(struct ether_header *eh, struct mbuf *m, - u_int16_t t); +static void vlan_input(struct ifnet *ifp, struct mbuf *m); static int vlan_ioctl(struct ifnet *ifp, u_long cmd, caddr_t addr); static int vlan_setmulti(struct ifnet *ifp); static int vlan_unconfig(struct ifnet *ifp); @@ -169,6 +182,21 @@ vlan_setmulti(struct ifnet *ifp) return(0); } +/* + * VLAN support can be loaded as a module. The only place in the + * system that's intimately aware of this is ether_input. We hook + * into this code through vlan_input_p which is defined there and + * set here. Noone else in the system should be aware of this so + * we use an explicit reference here. + * + * NB: Noone should ever need to check if vlan_input_p is null or + * not. This is because interfaces have a count of the number + * of active vlans (if_nvlans) and this should never be bumped + * except by vlan_config--which is in this module so therefore + * the module must be loaded and vlan_input_p must be non-NULL. + */ +extern void (*vlan_input_p)(struct ifnet *, struct mbuf *); + static int vlan_modevent(module_t mod, int type, void *data) { @@ -177,13 +205,11 @@ vlan_modevent(module_t mod, int type, void *data) case MOD_LOAD: LIST_INIT(&ifv_list); vlan_input_p = vlan_input; - vlan_input_tag_p = vlan_input_tag; if_clone_attach(&vlan_cloner); break; case MOD_UNLOAD: if_clone_detach(&vlan_cloner); vlan_input_p = NULL; - vlan_input_tag_p = NULL; while (!LIST_EMPTY(&ifv_list)) vlan_clone_destroy(&LIST_FIRST(&ifv_list)->ifv_if); break; @@ -225,13 +251,12 @@ vlan_clone_create(struct if_clone *ifc, int unit) ifp->if_init = vlan_ifinit; ifp->if_start = vlan_start; ifp->if_ioctl = vlan_ioctl; - ifp->if_output = ether_output; ifp->if_snd.ifq_maxlen = ifqmaxlen; - ether_ifattach(ifp, ETHER_BPF_SUPPORTED); + ether_ifattach(ifp, ifv->ifv_ac.ac_enaddr); /* Now undo some of the damage... */ ifp->if_baudrate = 0; - ifp->if_data.ifi_type = IFT_L2VLAN; - ifp->if_data.ifi_hdrlen = EVL_ENCAPLEN; + ifp->if_type = IFT_L2VLAN; + ifp->if_hdrlen = ETHER_VLAN_ENCAP_LEN; return (0); } @@ -247,7 +272,7 @@ vlan_clone_destroy(struct ifnet *ifp) vlan_unconfig(ifp); splx(s); - ether_ifdetach(ifp, ETHER_BPF_SUPPORTED); + ether_ifdetach(ifp); free(ifv, M_VLAN); } @@ -274,8 +299,7 @@ vlan_start(struct ifnet *ifp) IF_DEQUEUE(&ifp->if_snd, m); if (m == 0) break; - if (ifp->if_bpf) - bpf_mtap(ifp, m); + BPF_MTAP(ifp, m); /* * Do not run parent's if_start() if the parent is not up, @@ -284,53 +308,54 @@ vlan_start(struct ifnet *ifp) if ((p->if_flags & (IFF_UP | IFF_RUNNING)) != (IFF_UP | IFF_RUNNING)) { m_freem(m); - ifp->if_data.ifi_collisions++; + ifp->if_collisions++; continue; } /* - * If the LINK0 flag is set, it means the underlying interface - * can do VLAN tag insertion itself and doesn't require us to - * create a special header for it. In this case, we just pass - * the packet along. However, we need some way to tell the - * interface where the packet came from so that it knows how - * to find the VLAN tag to use, so we set the rcvif in the - * mbuf header to our ifnet. - * - * Note: we also set the M_PROTO1 flag in the mbuf to let - * the parent driver know that the rcvif pointer is really - * valid. We need to do this because sometimes mbufs will - * be allocated by other parts of the system that contain - * garbage in the rcvif pointer. Using the M_PROTO1 flag - * lets the driver perform a proper sanity check and avoid - * following potentially bogus rcvif pointers off into - * never-never land. + * If underlying interface can do VLAN tag insertion itself, + * just pass the packet along. However, we need some way to + * tell the interface where the packet came from so that it + * knows how to find the VLAN tag to use, so we attach a + * packet tag that holds it. */ - if (ifp->if_flags & IFF_LINK0) { - m->m_pkthdr.rcvif = ifp; - m->m_flags |= M_PROTO1; + if (ifp->if_capabilities & IFCAP_VLAN_HWTAGGING) { + struct m_tag *mtag = m_tag_alloc(MTAG_VLAN, + MTAG_VLAN_TAG, + sizeof (u_int), + M_DONTWAIT); + if (mtag == NULL) { + ifp->if_oerrors++; + m_freem(m); + continue; + } + *(u_int*)(mtag+1) = ifv->ifv_tag; + m_tag_prepend(m, mtag); } else { - M_PREPEND(m, EVL_ENCAPLEN, M_DONTWAIT); + M_PREPEND(m, ifv->ifv_encaplen, M_DONTWAIT); if (m == NULL) { - if_printf(ifp, "M_PREPEND failed"); + if_printf(ifp, "unable to prepend VLAN header"); ifp->if_ierrors++; continue; } /* M_PREPEND takes care of m_len, m_pkthdr.len for us */ - m = m_pullup(m, ETHER_HDR_LEN + EVL_ENCAPLEN); - if (m == NULL) { - if_printf(ifp, "m_pullup failed"); - ifp->if_ierrors++; - continue; + if (m->m_len < sizeof(*evl)) { + m = m_pullup(m, sizeof(*evl)); + if (m == NULL) { + if_printf(ifp, + "cannot pullup VLAN header"); + ifp->if_ierrors++; + continue; + } } /* * Transform the Ethernet header into an Ethernet header * with 802.1Q encapsulation. */ - bcopy(mtod(m, char *) + EVL_ENCAPLEN, mtod(m, char *), - sizeof(struct ether_header)); + bcopy(mtod(m, char *) + ifv->ifv_encaplen, + mtod(m, char *), sizeof(struct ether_header)); evl = mtod(m, struct ether_vlan_header *); evl->evl_proto = evl->evl_encap_proto; evl->evl_encap_proto = htons(ETHERTYPE_VLAN); @@ -355,91 +380,81 @@ vlan_start(struct ifnet *ifp) return; } -static int -vlan_input_tag(struct ether_header *eh, struct mbuf *m, u_int16_t t) +static void +vlan_input(struct ifnet *ifp, struct mbuf *m) { + struct ether_vlan_header *evl; struct ifvlan *ifv; + struct m_tag *mtag; + u_int tag; - /* - * Fake up a header and send the packet to the physical interface's - * bpf tap if active. - */ - if (m->m_pkthdr.rcvif->if_bpf != NULL) { - struct m_hdr mh; - struct ether_vlan_header evh; + mtag = m_tag_locate(m, MTAG_VLAN, MTAG_VLAN_TAG, NULL); + if (mtag != NULL) { + /* + * Packet is tagged, m contains a normal + * Ethernet frame; the tag is stored out-of-band. + */ + tag = *(u_int*)(mtag+1); + m_tag_delete(m, mtag); + } else { + switch (ifp->if_type) { + case IFT_ETHER: + if (m->m_len < sizeof (*evl) && + (m = m_pullup(m, sizeof (*evl))) == NULL) { + if_printf(ifp, "cannot pullup VLAN header\n"); + return; + } + evl = mtod(m, struct ether_vlan_header *); + KASSERT(ntohs(evl->evl_encap_proto) == ETHERTYPE_VLAN, + ("vlan_input: bad encapsulated protocols (%u)", + ntohs(evl->evl_encap_proto))); - bcopy(eh, &evh, 2*ETHER_ADDR_LEN); - evh.evl_encap_proto = htons(ETHERTYPE_VLAN); - evh.evl_tag = htons(t); - evh.evl_proto = eh->ether_type; + tag = EVL_VLANOFTAG(ntohs(evl->evl_tag)); - /* This kludge is OK; BPF treats the "mbuf" as read-only */ - mh.mh_next = m; - mh.mh_data = (char *)&evh; - mh.mh_len = ETHER_HDR_LEN + EVL_ENCAPLEN; - bpf_mtap(m->m_pkthdr.rcvif, (struct mbuf *)&mh); + /* + * Restore the original ethertype. We'll remove + * the encapsulation after we've found the vlan + * interface corresponding to the tag. + */ + evl->evl_encap_proto = evl->evl_proto; + break; + default: + tag = (u_int) -1; +#ifdef DIAGNOSTIC + panic("vlan_input: unsupported if type %u", ifp->if_type); +#endif + break; + } } for (ifv = LIST_FIRST(&ifv_list); ifv != NULL; - ifv = LIST_NEXT(ifv, ifv_list)) { - if (m->m_pkthdr.rcvif == ifv->ifv_p - && ifv->ifv_tag == t) + ifv = LIST_NEXT(ifv, ifv_list)) + if (ifp == ifv->ifv_p && tag == ifv->ifv_tag) break; - } if (ifv == NULL || (ifv->ifv_if.if_flags & IFF_UP) == 0) { - m->m_pkthdr.rcvif->if_noproto++; m_freem(m); - return -1; /* So the parent can take note */ + ifp->if_noproto++; + return; + } + + if (mtag == NULL) { + /* + * Packet had an in-line encapsulation header; + * remove it. The original header has already + * been fixed up above. + */ + bcopy(mtod(m, caddr_t), + mtod(m, caddr_t) + ETHER_VLAN_ENCAP_LEN, + sizeof (struct ether_header)); + m_adj(m, ETHER_VLAN_ENCAP_LEN); } - /* - * Having found a valid vlan interface corresponding to - * the given source interface and vlan tag, run the - * the real packet through ether_input(). - */ m->m_pkthdr.rcvif = &ifv->ifv_if; - ifv->ifv_if.if_ipackets++; - ether_input(&ifv->ifv_if, eh, m); - return 0; -} -static int -vlan_input(struct ether_header *eh, struct mbuf *m) -{ - struct ifvlan *ifv; - - for (ifv = LIST_FIRST(&ifv_list); ifv != NULL; - ifv = LIST_NEXT(ifv, ifv_list)) { - if (m->m_pkthdr.rcvif == ifv->ifv_p - && (EVL_VLANOFTAG(ntohs(*mtod(m, u_int16_t *))) - == ifv->ifv_tag)) - break; - } - - if (ifv == NULL || (ifv->ifv_if.if_flags & IFF_UP) == 0) { - m->m_pkthdr.rcvif->if_noproto++; - m_freem(m); - return -1; /* so ether_input can take note */ - } - - /* - * Having found a valid vlan interface corresponding to - * the given source interface and vlan tag, remove the - * encapsulation, and run the real packet through - * ether_input() a second time (it had better be - * reentrant!). - */ - m->m_pkthdr.rcvif = &ifv->ifv_if; - eh->ether_type = mtod(m, u_int16_t *)[1]; - m->m_data += EVL_ENCAPLEN; - m->m_len -= EVL_ENCAPLEN; - m->m_pkthdr.len -= EVL_ENCAPLEN; - - ifv->ifv_if.if_ipackets++; - ether_input(&ifv->ifv_if, eh, m); - return 0; + /* Pass it back through the parent's input routine. */ + (*ifp->if_input)(&ifv->ifv_if, m); } static int @@ -452,12 +467,50 @@ vlan_config(struct ifvlan *ifv, struct ifnet *p) return EPROTONOSUPPORT; if (ifv->ifv_p) return EBUSY; - ifv->ifv_p = p; - if (p->if_data.ifi_hdrlen == sizeof(struct ether_vlan_header)) - ifv->ifv_if.if_mtu = p->if_mtu; - else - ifv->ifv_if.if_mtu = p->if_data.ifi_mtu - EVL_ENCAPLEN; + ifv->ifv_encaplen = ETHER_VLAN_ENCAP_LEN; + ifv->ifv_mintu = ETHERMIN; + ifv->ifv_flags = 0; + + /* + * If the parent supports the VLAN_MTU capability, + * i.e. can Tx/Rx larger than ETHER_MAX_LEN frames, + * enable it. + */ + p->if_nvlans++; + if (p->if_nvlans == 1 && (p->if_capabilities & IFCAP_VLAN_MTU) != 0) { + /* + * Enable Tx/Rx of VLAN-sized frames. + */ + p->if_capenable |= IFCAP_VLAN_MTU; + if (p->if_flags & IFF_UP) { + struct ifreq ifr; + int error; + + ifr.ifr_flags = p->if_flags; + error = (*p->if_ioctl)(p, SIOCSIFFLAGS, + (caddr_t) &ifr); + if (error) { + p->if_nvlans--; + if (p->if_nvlans == 0) + p->if_capenable &= ~IFCAP_VLAN_MTU; + return (error); + } + } + ifv->ifv_mtufudge = 0; + } else if ((p->if_capabilities & IFCAP_VLAN_MTU) == 0) { + /* + * Fudge the MTU by the encapsulation size. This + * makes us incompatible with strictly compliant + * 802.1Q implementations, but allows us to use + * the feature with other NetBSD implementations, + * which might still be useful. + */ + ifv->ifv_mtufudge = ifv->ifv_encaplen; + } + + ifv->ifv_p = p; + ifv->ifv_if.if_mtu = p->if_mtu - ifv->ifv_mtufudge; /* * Copy only a selected subset of flags from the parent. * Other flags are none of our business. @@ -465,6 +518,14 @@ vlan_config(struct ifvlan *ifv, struct ifnet *p) ifv->ifv_if.if_flags = (p->if_flags & (IFF_BROADCAST | IFF_MULTICAST | IFF_SIMPLEX | IFF_POINTOPOINT)); + /* + * If the parent interface can do hardware-assisted + * VLAN encapsulation, then propagate its hardware- + * assisted checksumming flags. + */ + if (p->if_capabilities & IFCAP_VLAN_HWTAGGING) + ifv->ifv_if.if_capabilities |= p->if_capabilities & IFCAP_HWCSUM; + /* * Set up our ``Ethernet address'' to reflect the underlying * physical interface's. @@ -524,11 +585,26 @@ vlan_unconfig(struct ifnet *ifp) SLIST_REMOVE_HEAD(&ifv->vlan_mc_listhead, mc_entries); free(mc, M_VLAN); } + + p->if_nvlans--; + if (p->if_nvlans == 0) { + /* + * Disable Tx/Rx of VLAN-sized frames. + */ + p->if_capenable &= ~IFCAP_VLAN_MTU; + if (p->if_flags & IFF_UP) { + struct ifreq ifr; + + ifr.ifr_flags = p->if_flags; + (*p->if_ioctl)(p, SIOCSIFFLAGS, (caddr_t) &ifr); + } + } } /* Disconnect from parent. */ ifv->ifv_p = NULL; - ifv->ifv_if.if_mtu = ETHERMTU; + ifv->ifv_if.if_mtu = ETHERMTU; /* XXX why not 0? */ + ifv->ifv_flags = 0; /* Clear our MAC address. */ ifa = ifaddr_byindex(ifv->ifv_if.if_index); @@ -541,6 +617,29 @@ vlan_unconfig(struct ifnet *ifp) return 0; } +static int +vlan_set_promisc(struct ifnet *ifp) +{ + struct ifvlan *ifv = ifp->if_softc; + int error = 0; + + if ((ifp->if_flags & IFF_PROMISC) != 0) { + if ((ifv->ifv_flags & IFVF_PROMISC) == 0) { + error = ifpromisc(ifv->ifv_p, 1); + if (error == 0) + ifv->ifv_flags |= IFVF_PROMISC; + } + } else { + if ((ifv->ifv_flags & IFVF_PROMISC) != 0) { + error = ifpromisc(ifv->ifv_p, 0); + if (error == 0) + ifv->ifv_flags &= ~IFVF_PROMISC; + } + } + + return (error); +} + static int vlan_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) { @@ -583,14 +682,17 @@ vlan_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) case SIOCSIFMTU: /* * Set the interface MTU. - * This is bogus. The underlying interface might support - * jumbo frames. */ - if (ifr->ifr_mtu > ETHERMTU) { + if (ifv->ifv_p != NULL) { + if (ifr->ifr_mtu > + (ifv->ifv_p->if_mtu - ifv->ifv_mtufudge) || + ifr->ifr_mtu < + (ifv->ifv_mintu - ifv->ifv_mtufudge)) + error = EINVAL; + else + ifp->if_mtu = ifr->ifr_mtu; + } else error = EINVAL; - } else { - ifp->if_mtu = ifr->ifr_mtu; - } break; case SIOCSETVLAN: @@ -617,6 +719,9 @@ vlan_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) break; ifv->ifv_tag = vlr.vlr_tag; ifp->if_flags |= IFF_RUNNING; + + /* Update promiscuous mode, if necessary. */ + vlan_set_promisc(ifp); break; case SIOCGETVLAN: @@ -631,15 +736,13 @@ vlan_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) case SIOCSIFFLAGS: /* - * We don't support promiscuous mode - * right now because it would require help from the - * underlying drivers, which hasn't been implemented. + * For promiscuous mode, we enable promiscuous mode on + * the parent if we need promiscuous on the VLAN interface. */ - if (ifr->ifr_flags & (IFF_PROMISC)) { - ifp->if_flags &= ~(IFF_PROMISC); - error = EINVAL; - } + if (ifv->ifv_p != NULL) + error = vlan_set_promisc(ifp); break; + case SIOCADDMULTI: case SIOCDELMULTI: error = vlan_setmulti(ifp); diff --git a/sys/net/if_vlan_var.h b/sys/net/if_vlan_var.h index c74064a4730d..42f2dcc92002 100644 --- a/sys/net/if_vlan_var.h +++ b/sys/net/if_vlan_var.h @@ -32,27 +32,6 @@ #ifndef _NET_IF_VLAN_VAR_H_ #define _NET_IF_VLAN_VAR_H_ 1 -#ifdef _KERNEL -struct vlan_mc_entry { - struct ether_addr mc_addr; - SLIST_ENTRY(vlan_mc_entry) mc_entries; -}; - -struct ifvlan { - struct arpcom ifv_ac; /* make this an interface */ - struct ifnet *ifv_p; /* parent inteface of this vlan */ - struct ifv_linkmib { - int ifvm_parent; - u_int16_t ifvm_proto; /* encapsulation ethertype */ - u_int16_t ifvm_tag; /* tag to apply on packets leaving if */ - } ifv_mib; - SLIST_HEAD(__vlan_mchead, vlan_mc_entry) vlan_mc_listhead; - LIST_ENTRY(ifvlan) ifv_list; -}; -#define ifv_if ifv_ac.ac_if -#define ifv_tag ifv_mib.ifvm_tag -#endif /* _KERNEL */ - struct ether_vlan_header { u_char evl_dhost[ETHER_ADDR_LEN]; u_char evl_shost[ETHER_ADDR_LEN]; @@ -63,7 +42,6 @@ struct ether_vlan_header { #define EVL_VLANOFTAG(tag) ((tag) & 4095) #define EVL_PRIOFTAG(tag) (((tag) >> 13) & 7) -#define EVL_ENCAPLEN 4 /* length in octets of encapsulation */ /* sysctl(3) tags, for compatibility purposes */ #define VLANCTL_PROTO 1 @@ -79,4 +57,61 @@ struct vlanreq { #define SIOCSETVLAN SIOCSIFGENERIC #define SIOCGETVLAN SIOCGIFGENERIC +#ifdef _KERNEL +/* + * Drivers that are capable of adding and removing the VLAN header + * in hardware indicate they support this by marking IFCAP_VLAN_HWTAGGING + * in if_capabilities. Drivers for hardware that is also capable + * of handling larger MTU's that may include a software-appended + * VLAN header w/o lowering the normal MTU should mark IFCAP_VLA_MTU + * in if_capabilities; this notfies the VLAN code it can leave the + * MTU on the vlan interface at the normal setting. + */ + +/* + * Drivers that support hardware VLAN tagging pass a packet's tag + * up through the stack by appending a packet tag with this value. + * Output is handled likewise, the driver must locate the packet + * tag to extract the VLAN tag. The following macros are used to + * do this work. On input, do: + * + * VLAN_INPUT_TAG(ifp, m, tag,); + * + * to mark the packet m with the specified VLAN tag. The last + * parameter provides code to execute in case of an error. On + * output the driver should check ifnet to see if any VLANs are + * in use and only then check for a packet tag; this is done with: + * + * struct m_tag *mtag; + * mtag = VLAN_OUTPUT_TAG(ifp, m); + * if (mtag != NULL) { + * ... = VLAN_TAG_VALUE(mtag); + * ... pass tag to hardware ... + * } + * + * Note that a driver must indicate it supports hardware VLAN + * tagging by marking IFCAP_VLAN_HWTAGGING in if_capabilities. + */ +#define MTAG_VLAN 1035328035 +#define MTAG_VLAN_TAG 0 /* tag of VLAN interface */ + +#define VLAN_INPUT_TAG(_ifp, _m, _t, _errcase) do { \ + struct m_tag *mtag; \ + mtag = m_tag_alloc(MTAG_VLAN, MTAG_VLAN_TAG, \ + sizeof (u_int), M_DONTWAIT); \ + if (mtag == NULL) { \ + (_ifp)->if_ierrors++; \ + m_freem(_m); \ + _errcase; \ + } \ + *(u_int *)(mtag+1) = (_t); \ + m_tag_prepend((_m), mtag); \ +} while (0) + +#define VLAN_OUTPUT_TAG(_ifp, _m) \ + ((_ifp)->if_nvlans != 0 ? \ + m_tag_locate((_m), MTAG_VLAN, MTAG_VLAN_TAG, NULL) : NULL) +#define VLAN_TAG_VALUE(_mt) (*(u_int *)((_mt)+1)) +#endif /* _KERNEL */ + #endif /* _NET_IF_VLAN_VAR_H_ */