diff --git a/fs/afs/Makefile b/fs/afs/Makefile index cca198b2caed23b25258abd70ed62eb8039334e5..01545eb1d87237f54c558c616720bc1a18813579 100644 --- a/fs/afs/Makefile +++ b/fs/afs/Makefile @@ -18,6 +18,7 @@ kafs-objs := \ security.o \ server.o \ super.o \ + use-rtnetlink.o \ vlclient.o \ vlocation.o \ vnode.o \ diff --git a/fs/afs/afs_cm.h b/fs/afs/afs_cm.h index 7c8e3d43c8e551ec8eba1505935d0c87e7699565..d4bd201cc31edac80806d45f2aba6d59e33979df 100644 --- a/fs/afs/afs_cm.h +++ b/fs/afs/afs_cm.h @@ -23,6 +23,9 @@ enum AFS_CM_Operations { CBGetCE = 208, /* get cache file description */ CBGetXStatsVersion = 209, /* get version of extended statistics */ CBGetXStats = 210, /* get contents of extended statistics data */ + CBGetCapabilities = 65538, /* get client capabilities */ }; +#define AFS_CAP_ERROR_TRANSLATION 0x1 + #endif /* AFS_FS_H */ diff --git a/fs/afs/cmservice.c b/fs/afs/cmservice.c index c3ec57a237bfb16443bd94d29619caa7bf620d06..a6af3acf016e9984b0fad7de1a658112287bf57c 100644 --- a/fs/afs/cmservice.c +++ b/fs/afs/cmservice.c @@ -22,6 +22,8 @@ static int afs_deliver_cb_init_call_back_state(struct afs_call *, struct sk_buff *, bool); static int afs_deliver_cb_probe(struct afs_call *, struct sk_buff *, bool); static int afs_deliver_cb_callback(struct afs_call *, struct sk_buff *, bool); +static int afs_deliver_cb_get_capabilities(struct afs_call *, struct sk_buff *, + bool); static void afs_cm_destructor(struct afs_call *); /* @@ -54,6 +56,16 @@ static const struct afs_call_type afs_SRXCBProbe = { .destructor = afs_cm_destructor, }; +/* + * CB.GetCapabilities operation type + */ +static const struct afs_call_type afs_SRXCBGetCapabilites = { + .name = "CB.GetCapabilities", + .deliver = afs_deliver_cb_get_capabilities, + .abort_to_error = afs_abort_to_error, + .destructor = afs_cm_destructor, +}; + /* * route an incoming cache manager call * - return T if supported, F if not @@ -74,6 +86,9 @@ bool afs_cm_incoming_call(struct afs_call *call) case CBProbe: call->type = &afs_SRXCBProbe; return true; + case CBGetCapabilities: + call->type = &afs_SRXCBGetCapabilites; + return true; default: return false; } @@ -328,3 +343,86 @@ static int afs_deliver_cb_probe(struct afs_call *call, struct sk_buff *skb, schedule_work(&call->work); return 0; } + +/* + * allow the fileserver to ask about the cache manager's capabilities + */ +static void SRXAFSCB_GetCapabilities(struct work_struct *work) +{ + struct afs_interface *ifs; + struct afs_call *call = container_of(work, struct afs_call, work); + int loop, nifs; + + struct { + struct /* InterfaceAddr */ { + __be32 nifs; + __be32 uuid[11]; + __be32 ifaddr[32]; + __be32 netmask[32]; + __be32 mtu[32]; + } ia; + struct /* Capabilities */ { + __be32 capcount; + __be32 caps[1]; + } cap; + } reply; + + _enter(""); + + nifs = 0; + ifs = kcalloc(32, sizeof(*ifs), GFP_KERNEL); + if (ifs) { + nifs = afs_get_ipv4_interfaces(ifs, 32, false); + if (nifs < 0) { + kfree(ifs); + ifs = NULL; + nifs = 0; + } + } + + memset(&reply, 0, sizeof(reply)); + reply.ia.nifs = htonl(nifs); + + reply.ia.uuid[0] = htonl(afs_uuid.time_low); + reply.ia.uuid[1] = htonl(afs_uuid.time_mid); + reply.ia.uuid[2] = htonl(afs_uuid.time_hi_and_version); + reply.ia.uuid[3] = htonl((s8) afs_uuid.clock_seq_hi_and_reserved); + reply.ia.uuid[4] = htonl((s8) afs_uuid.clock_seq_low); + for (loop = 0; loop < 6; loop++) + reply.ia.uuid[loop + 5] = htonl((s8) afs_uuid.node[loop]); + + if (ifs) { + for (loop = 0; loop < nifs; loop++) { + reply.ia.ifaddr[loop] = ifs[loop].address.s_addr; + reply.ia.netmask[loop] = ifs[loop].netmask.s_addr; + reply.ia.mtu[loop] = htonl(ifs[loop].mtu); + } + } + + reply.cap.capcount = htonl(1); + reply.cap.caps[0] = htonl(AFS_CAP_ERROR_TRANSLATION); + afs_send_simple_reply(call, &reply, sizeof(reply)); + + _leave(""); +} + +/* + * deliver request data to a CB.GetCapabilities call + */ +static int afs_deliver_cb_get_capabilities(struct afs_call *call, + struct sk_buff *skb, bool last) +{ + _enter(",{%u},%d", skb->len, last); + + if (skb->len > 0) + return -EBADMSG; + if (!last) + return 0; + + /* no unmarshalling required */ + call->state = AFS_CALL_REPLYING; + + INIT_WORK(&call->work, SRXAFSCB_GetCapabilities); + schedule_work(&call->work); + return 0; +} diff --git a/fs/afs/internal.h b/fs/afs/internal.h index 8bed2429d01ff1f1f09ffa47b52739d1675e1624..6120d4bd19e0b652c0b579f1a184e35f3c895a0b 100644 --- a/fs/afs/internal.h +++ b/fs/afs/internal.h @@ -346,6 +346,40 @@ struct afs_permits { struct afs_permit permits[0]; /* the permits so far examined */ }; +/* + * record of one of a system's set of network interfaces + */ +struct afs_interface { + unsigned index; /* interface index */ + struct in_addr address; /* IPv4 address bound to interface */ + struct in_addr netmask; /* netmask applied to address */ + unsigned mtu; /* MTU of interface */ +}; + +/* + * UUID definition [internet draft] + * - the timestamp is a 60-bit value, split 32/16/12, and goes in 100ns + * increments since midnight 15th October 1582 + * - add AFS_UUID_TO_UNIX_TIME to convert unix time in 100ns units to UUID + * time + * - the clock sequence is a 14-bit counter to avoid duplicate times + */ +struct afs_uuid { + u32 time_low; /* low part of timestamp */ + u16 time_mid; /* mid part of timestamp */ + u16 time_hi_and_version; /* high part of timestamp and version */ +#define AFS_UUID_TO_UNIX_TIME 0x01b21dd213814000 +#define AFS_UUID_TIMEHI_MASK 0x0fff +#define AFS_UUID_VERSION_TIME 0x1000 /* time-based UUID */ +#define AFS_UUID_VERSION_NAME 0x3000 /* name-based UUID */ +#define AFS_UUID_VERSION_RANDOM 0x4000 /* (pseudo-)random generated UUID */ + u8 clock_seq_hi_and_reserved; /* clock seq hi and variant */ +#define AFS_UUID_CLOCKHI_MASK 0x3f +#define AFS_UUID_VARIANT_STD 0x80 + u8 clock_seq_low; /* clock seq low */ + u8 node[6]; /* spatially unique node ID (MAC addr) */ +}; + /*****************************************************************************/ /* * callback.c @@ -430,6 +464,7 @@ extern void afs_clear_inode(struct inode *); /* * main.c */ +extern struct afs_uuid afs_uuid; #ifdef AFS_CACHING_SUPPORT extern struct cachefs_netfs afs_cache_netfs; #endif @@ -470,6 +505,7 @@ extern struct afs_call *afs_alloc_flat_call(const struct afs_call_type *, extern void afs_flat_call_destructor(struct afs_call *); extern void afs_transfer_reply(struct afs_call *, struct sk_buff *); extern void afs_send_empty_reply(struct afs_call *); +extern void afs_send_simple_reply(struct afs_call *, const void *, size_t); extern int afs_extract_data(struct afs_call *, struct sk_buff *, bool, void *, size_t); @@ -500,6 +536,12 @@ extern void __exit afs_purge_servers(void); extern int afs_fs_init(void); extern void afs_fs_exit(void); +/* + * use-rtnetlink.c + */ +extern int afs_get_ipv4_interfaces(struct afs_interface *, size_t, bool); +extern int afs_get_MAC_address(u8 [6]); + /* * vlclient.c */ diff --git a/fs/afs/main.c b/fs/afs/main.c index 0cf1b021ad543238fd8787fdf826d81b25d87630..40c2704e7557c4093b07df5130d9dbe851aa38ed 100644 --- a/fs/afs/main.c +++ b/fs/afs/main.c @@ -40,6 +40,51 @@ struct cachefs_netfs afs_cache_netfs = { }; #endif +struct afs_uuid afs_uuid; + +/* + * get a client UUID + */ +static int __init afs_get_client_UUID(void) +{ + struct timespec ts; + u64 uuidtime; + u16 clockseq; + int ret; + + /* read the MAC address of one of the external interfaces and construct + * a UUID from it */ + ret = afs_get_MAC_address(afs_uuid.node); + if (ret < 0) + return ret; + + getnstimeofday(&ts); + uuidtime = (u64) ts.tv_sec * 1000 * 1000 * 10; + uuidtime += ts.tv_nsec / 100; + uuidtime += AFS_UUID_TO_UNIX_TIME; + afs_uuid.time_low = uuidtime; + afs_uuid.time_mid = uuidtime >> 32; + afs_uuid.time_hi_and_version = (uuidtime >> 48) & AFS_UUID_TIMEHI_MASK; + afs_uuid.time_hi_and_version = AFS_UUID_VERSION_TIME; + + get_random_bytes(&clockseq, 2); + afs_uuid.clock_seq_low = clockseq; + afs_uuid.clock_seq_hi_and_reserved = + (clockseq >> 8) & AFS_UUID_CLOCKHI_MASK; + afs_uuid.clock_seq_hi_and_reserved = AFS_UUID_VARIANT_STD; + + _debug("AFS UUID: %08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x", + afs_uuid.time_low, + afs_uuid.time_mid, + afs_uuid.time_hi_and_version, + afs_uuid.clock_seq_hi_and_reserved, + afs_uuid.clock_seq_low, + afs_uuid.node[0], afs_uuid.node[1], afs_uuid.node[2], + afs_uuid.node[3], afs_uuid.node[4], afs_uuid.node[5]); + + return 0; +} + /* * initialise the AFS client FS module */ @@ -49,6 +94,10 @@ static int __init afs_init(void) printk(KERN_INFO "kAFS: Red Hat AFS client v0.1 registering.\n"); + ret = afs_get_client_UUID(); + if (ret < 0) + return ret; + /* register the /proc stuff */ ret = afs_proc_init(); if (ret < 0) diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c index e86c527d87a152a200d088b146bbfa18674b29b2..e7b047328a39df53e6efb774f95baaddc9dcd14e 100644 --- a/fs/afs/rxrpc.c +++ b/fs/afs/rxrpc.c @@ -713,6 +713,45 @@ void afs_send_empty_reply(struct afs_call *call) } } +/* + * send a simple reply + */ +void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len) +{ + struct msghdr msg; + struct iovec iov[1]; + + _enter(""); + + iov[0].iov_base = (void *) buf; + iov[0].iov_len = len; + msg.msg_name = NULL; + msg.msg_namelen = 0; + msg.msg_iov = iov; + msg.msg_iovlen = 1; + msg.msg_control = NULL; + msg.msg_controllen = 0; + msg.msg_flags = 0; + + call->state = AFS_CALL_AWAIT_ACK; + switch (rxrpc_kernel_send_data(call->rxcall, &msg, len)) { + case 0: + _leave(" [replied]"); + return; + + case -ENOMEM: + _debug("oom"); + rxrpc_kernel_abort_call(call->rxcall, RX_USER_ABORT); + default: + rxrpc_kernel_end_call(call->rxcall); + call->rxcall = NULL; + call->type->destructor(call); + afs_free_call(call); + _leave(" [error]"); + return; + } +} + /* * extract a piece of data from the received data socket buffers */ diff --git a/fs/afs/use-rtnetlink.c b/fs/afs/use-rtnetlink.c new file mode 100644 index 0000000000000000000000000000000000000000..82f0daa28970ea92d97e1041b4a34c5a86b79e3e --- /dev/null +++ b/fs/afs/use-rtnetlink.c @@ -0,0 +1,473 @@ +/* RTNETLINK client + * + * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.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 +#include +#include +#include +#include +#include +#include "internal.h" + +struct afs_rtm_desc { + struct socket *nlsock; + struct afs_interface *bufs; + u8 *mac; + size_t nbufs; + size_t maxbufs; + void *data; + ssize_t datalen; + size_t datamax; + int msg_seq; + unsigned mac_index; + bool wantloopback; + int (*parse)(struct afs_rtm_desc *, struct nlmsghdr *); +}; + +/* + * parse an RTM_GETADDR response + */ +static int afs_rtm_getaddr_parse(struct afs_rtm_desc *desc, + struct nlmsghdr *nlhdr) +{ + struct afs_interface *this; + struct ifaddrmsg *ifa; + struct rtattr *rtattr; + const char *name; + size_t len; + + ifa = (struct ifaddrmsg *) NLMSG_DATA(nlhdr); + + _enter("{ix=%d,af=%d}", ifa->ifa_index, ifa->ifa_family); + + if (ifa->ifa_family != AF_INET) { + _leave(" = 0 [family %d]", ifa->ifa_family); + return 0; + } + if (desc->nbufs >= desc->maxbufs) { + _leave(" = 0 [max %zu/%zu]", desc->nbufs, desc->maxbufs); + return 0; + } + + this = &desc->bufs[desc->nbufs]; + + this->index = ifa->ifa_index; + this->netmask.s_addr = inet_make_mask(ifa->ifa_prefixlen); + this->mtu = 0; + + rtattr = NLMSG_DATA(nlhdr) + NLMSG_ALIGN(sizeof(struct ifaddrmsg)); + len = NLMSG_PAYLOAD(nlhdr, sizeof(struct ifaddrmsg)); + + name = "unknown"; + for (; RTA_OK(rtattr, len); rtattr = RTA_NEXT(rtattr, len)) { + switch (rtattr->rta_type) { + case IFA_ADDRESS: + memcpy(&this->address, RTA_DATA(rtattr), 4); + break; + case IFA_LABEL: + name = RTA_DATA(rtattr); + break; + } + } + + _debug("%s: "NIPQUAD_FMT"/"NIPQUAD_FMT, + name, NIPQUAD(this->address), NIPQUAD(this->netmask)); + + desc->nbufs++; + _leave(" = 0"); + return 0; +} + +/* + * parse an RTM_GETLINK response for MTUs + */ +static int afs_rtm_getlink_if_parse(struct afs_rtm_desc *desc, + struct nlmsghdr *nlhdr) +{ + struct afs_interface *this; + struct ifinfomsg *ifi; + struct rtattr *rtattr; + const char *name; + size_t len, loop; + + ifi = (struct ifinfomsg *) NLMSG_DATA(nlhdr); + + _enter("{ix=%d}", ifi->ifi_index); + + for (loop = 0; loop < desc->nbufs; loop++) { + this = &desc->bufs[loop]; + if (this->index == ifi->ifi_index) + goto found; + } + + _leave(" = 0 [no match]"); + return 0; + +found: + if (ifi->ifi_type == ARPHRD_LOOPBACK && !desc->wantloopback) { + _leave(" = 0 [loopback]"); + return 0; + } + + rtattr = NLMSG_DATA(nlhdr) + NLMSG_ALIGN(sizeof(struct ifinfomsg)); + len = NLMSG_PAYLOAD(nlhdr, sizeof(struct ifinfomsg)); + + name = "unknown"; + for (; RTA_OK(rtattr, len); rtattr = RTA_NEXT(rtattr, len)) { + switch (rtattr->rta_type) { + case IFLA_MTU: + memcpy(&this->mtu, RTA_DATA(rtattr), 4); + break; + case IFLA_IFNAME: + name = RTA_DATA(rtattr); + break; + } + } + + _debug("%s: "NIPQUAD_FMT"/"NIPQUAD_FMT" mtu %u", + name, NIPQUAD(this->address), NIPQUAD(this->netmask), + this->mtu); + + _leave(" = 0"); + return 0; +} + +/* + * parse an RTM_GETLINK response for the MAC address belonging to the lowest + * non-internal interface + */ +static int afs_rtm_getlink_mac_parse(struct afs_rtm_desc *desc, + struct nlmsghdr *nlhdr) +{ + struct ifinfomsg *ifi; + struct rtattr *rtattr; + const char *name; + size_t remain, len; + bool set; + + ifi = (struct ifinfomsg *) NLMSG_DATA(nlhdr); + + _enter("{ix=%d}", ifi->ifi_index); + + if (ifi->ifi_index >= desc->mac_index) { + _leave(" = 0 [high]"); + return 0; + } + if (ifi->ifi_type == ARPHRD_LOOPBACK) { + _leave(" = 0 [loopback]"); + return 0; + } + + rtattr = NLMSG_DATA(nlhdr) + NLMSG_ALIGN(sizeof(struct ifinfomsg)); + remain = NLMSG_PAYLOAD(nlhdr, sizeof(struct ifinfomsg)); + + name = "unknown"; + set = false; + for (; RTA_OK(rtattr, remain); rtattr = RTA_NEXT(rtattr, remain)) { + switch (rtattr->rta_type) { + case IFLA_ADDRESS: + len = RTA_PAYLOAD(rtattr); + memcpy(desc->mac, RTA_DATA(rtattr), + min_t(size_t, len, 6)); + desc->mac_index = ifi->ifi_index; + set = true; + break; + case IFLA_IFNAME: + name = RTA_DATA(rtattr); + break; + } + } + + if (set) + _debug("%s: %02x:%02x:%02x:%02x:%02x:%02x", + name, + desc->mac[0], desc->mac[1], desc->mac[2], + desc->mac[3], desc->mac[4], desc->mac[5]); + + _leave(" = 0"); + return 0; +} + +/* + * read the rtnetlink response and pass to parsing routine + */ +static int afs_read_rtm(struct afs_rtm_desc *desc) +{ + struct nlmsghdr *nlhdr, tmphdr; + struct msghdr msg; + struct kvec iov[1]; + void *data; + bool last = false; + int len, ret, remain; + + _enter(""); + + do { + /* first of all peek to see how big the packet is */ + memset(&msg, 0, sizeof(msg)); + iov[0].iov_base = &tmphdr; + iov[0].iov_len = sizeof(tmphdr); + len = kernel_recvmsg(desc->nlsock, &msg, iov, 1, + sizeof(tmphdr), MSG_PEEK | MSG_TRUNC); + if (len < 0) { + _leave(" = %d [peek]", len); + return len; + } + if (len == 0) + continue; + if (len < sizeof(tmphdr) || len < NLMSG_PAYLOAD(&tmphdr, 0)) { + _leave(" = -EMSGSIZE"); + return -EMSGSIZE; + } + + if (desc->datamax < len) { + kfree(desc->data); + desc->data = NULL; + data = kmalloc(len, GFP_KERNEL); + if (!data) + return -ENOMEM; + desc->data = data; + } + desc->datamax = len; + + /* read all the data from this packet */ + iov[0].iov_base = desc->data; + iov[0].iov_len = desc->datamax; + desc->datalen = kernel_recvmsg(desc->nlsock, &msg, iov, 1, + desc->datamax, 0); + if (desc->datalen < 0) { + _leave(" = %ld [recv]", desc->datalen); + return desc->datalen; + } + + nlhdr = desc->data; + + /* check if the header is valid */ + if (!NLMSG_OK(nlhdr, desc->datalen) || + nlhdr->nlmsg_type == NLMSG_ERROR) { + _leave(" = -EIO"); + return -EIO; + } + + /* see if this is the last message */ + if (nlhdr->nlmsg_type == NLMSG_DONE || + !(nlhdr->nlmsg_flags & NLM_F_MULTI)) + last = true; + + /* parse the bits we got this time */ + nlmsg_for_each_msg(nlhdr, desc->data, desc->datalen, remain) { + ret = desc->parse(desc, nlhdr); + if (ret < 0) { + _leave(" = %d [parse]", ret); + return ret; + } + } + + } while (!last); + + _leave(" = 0"); + return 0; +} + +/* + * list the interface bound addresses to get the address and netmask + */ +static int afs_rtm_getaddr(struct afs_rtm_desc *desc) +{ + struct msghdr msg; + struct kvec iov[1]; + int ret; + + struct { + struct nlmsghdr nl_msg __attribute__((aligned(NLMSG_ALIGNTO))); + struct ifaddrmsg addr_msg __attribute__((aligned(NLMSG_ALIGNTO))); + } request; + + _enter(""); + + memset(&request, 0, sizeof(request)); + + request.nl_msg.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifaddrmsg)); + request.nl_msg.nlmsg_type = RTM_GETADDR; + request.nl_msg.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP; + request.nl_msg.nlmsg_seq = desc->msg_seq++; + request.nl_msg.nlmsg_pid = 0; + + memset(&msg, 0, sizeof(msg)); + iov[0].iov_base = &request; + iov[0].iov_len = sizeof(request); + + ret = kernel_sendmsg(desc->nlsock, &msg, iov, 1, iov[0].iov_len); + _leave(" = %d", ret); + return ret; +} + +/* + * list the interface link statuses to get the MTUs + */ +static int afs_rtm_getlink(struct afs_rtm_desc *desc) +{ + struct msghdr msg; + struct kvec iov[1]; + int ret; + + struct { + struct nlmsghdr nl_msg __attribute__((aligned(NLMSG_ALIGNTO))); + struct ifinfomsg link_msg __attribute__((aligned(NLMSG_ALIGNTO))); + } request; + + _enter(""); + + memset(&request, 0, sizeof(request)); + + request.nl_msg.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)); + request.nl_msg.nlmsg_type = RTM_GETLINK; + request.nl_msg.nlmsg_flags = NLM_F_REQUEST | NLM_F_ROOT; + request.nl_msg.nlmsg_seq = desc->msg_seq++; + request.nl_msg.nlmsg_pid = 0; + + memset(&msg, 0, sizeof(msg)); + iov[0].iov_base = &request; + iov[0].iov_len = sizeof(request); + + ret = kernel_sendmsg(desc->nlsock, &msg, iov, 1, iov[0].iov_len); + _leave(" = %d", ret); + return ret; +} + +/* + * cull any interface records for which there isn't an MTU value + */ +static void afs_cull_interfaces(struct afs_rtm_desc *desc) +{ + struct afs_interface *bufs = desc->bufs; + size_t nbufs = desc->nbufs; + int loop, point = 0; + + _enter("{%zu}", nbufs); + + for (loop = 0; loop < nbufs; loop++) { + if (desc->bufs[loop].mtu != 0) { + if (loop != point) { + ASSERTCMP(loop, >, point); + bufs[point] = bufs[loop]; + } + point++; + } + } + + desc->nbufs = point; + _leave(" [%zu/%zu]", desc->nbufs, nbufs); +} + +/* + * get a list of this system's interface IPv4 addresses, netmasks and MTUs + * - returns the number of interface records in the buffer + */ +int afs_get_ipv4_interfaces(struct afs_interface *bufs, size_t maxbufs, + bool wantloopback) +{ + struct afs_rtm_desc desc; + int ret, loop; + + _enter(""); + + memset(&desc, 0, sizeof(desc)); + desc.bufs = bufs; + desc.maxbufs = maxbufs; + desc.wantloopback = wantloopback; + + ret = sock_create_kern(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE, + &desc.nlsock); + if (ret < 0) { + _leave(" = %d [sock]", ret); + return ret; + } + + /* issue RTM_GETADDR */ + desc.parse = afs_rtm_getaddr_parse; + ret = afs_rtm_getaddr(&desc); + if (ret < 0) + goto error; + ret = afs_read_rtm(&desc); + if (ret < 0) + goto error; + + /* issue RTM_GETLINK */ + desc.parse = afs_rtm_getlink_if_parse; + ret = afs_rtm_getlink(&desc); + if (ret < 0) + goto error; + ret = afs_read_rtm(&desc); + if (ret < 0) + goto error; + + afs_cull_interfaces(&desc); + ret = desc.nbufs; + + for (loop = 0; loop < ret; loop++) + _debug("[%d] "NIPQUAD_FMT"/"NIPQUAD_FMT" mtu %u", + bufs[loop].index, + NIPQUAD(bufs[loop].address), + NIPQUAD(bufs[loop].netmask), + bufs[loop].mtu); + +error: + kfree(desc.data); + sock_release(desc.nlsock); + _leave(" = %d", ret); + return ret; +} + +/* + * get a MAC address from a random ethernet interface that has a real one + * - the buffer should be 6 bytes in size + */ +int afs_get_MAC_address(u8 mac[6]) +{ + struct afs_rtm_desc desc; + int ret; + + _enter(""); + + memset(&desc, 0, sizeof(desc)); + desc.mac = mac; + desc.mac_index = UINT_MAX; + + ret = sock_create_kern(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE, + &desc.nlsock); + if (ret < 0) { + _leave(" = %d [sock]", ret); + return ret; + } + + /* issue RTM_GETLINK */ + desc.parse = afs_rtm_getlink_mac_parse; + ret = afs_rtm_getlink(&desc); + if (ret < 0) + goto error; + ret = afs_read_rtm(&desc); + if (ret < 0) + goto error; + + if (desc.mac_index < UINT_MAX) { + /* got a MAC address */ + _debug("[%d] %02x:%02x:%02x:%02x:%02x:%02x", + desc.mac_index, + mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]); + } else { + ret = -ENONET; + } + +error: + sock_release(desc.nlsock); + _leave(" = %d", ret); + return ret; +}