diff options
Diffstat (limited to 'pfinet/linux-src/net/core/rtnetlink.c')
-rw-r--r-- | pfinet/linux-src/net/core/rtnetlink.c | 512 |
1 files changed, 512 insertions, 0 deletions
diff --git a/pfinet/linux-src/net/core/rtnetlink.c b/pfinet/linux-src/net/core/rtnetlink.c new file mode 100644 index 00000000..7f89e54a --- /dev/null +++ b/pfinet/linux-src/net/core/rtnetlink.c @@ -0,0 +1,512 @@ +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * Routing netlink socket interface: protocol independent part. + * + * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> + * + * 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. + * + * Fixes: + * Vitaly E. Lavrov RTA_OK arithmetics was wrong. + * Alexey Zhuravlev ifi_change does something useful + */ + +#include <linux/config.h> +#include <linux/errno.h> +#include <linux/types.h> +#include <linux/socket.h> +#include <linux/kernel.h> +#include <linux/major.h> +#include <linux/sched.h> +#include <linux/timer.h> +#include <linux/string.h> +#include <linux/sockios.h> +#include <linux/net.h> +#include <linux/fcntl.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/interrupt.h> +#include <linux/capability.h> +#include <linux/skbuff.h> +#include <linux/init.h> + +#include <asm/uaccess.h> +#include <asm/system.h> +#include <asm/string.h> + +#include <linux/inet.h> +#include <linux/netdevice.h> +#include <net/ip.h> +#include <net/protocol.h> +#include <net/arp.h> +#include <net/route.h> +#include <net/tcp.h> +#include <net/udp.h> +#include <net/sock.h> +#include <net/pkt_sched.h> + +atomic_t rtnl_rlockct; +struct wait_queue *rtnl_wait; + + +void rtnl_lock() +{ + rtnl_shlock(); + rtnl_exlock(); +} + +void rtnl_unlock() +{ + rtnl_exunlock(); + rtnl_shunlock(); +} + +int rtattr_parse(struct rtattr *tb[], int maxattr, struct rtattr *rta, int len) +{ + memset(tb, 0, sizeof(struct rtattr*)*maxattr); + + while (RTA_OK(rta, len)) { + unsigned flavor = rta->rta_type; + if (flavor && flavor <= maxattr) + tb[flavor-1] = rta; + rta = RTA_NEXT(rta, len); + } + return 0; +} + +#ifdef CONFIG_RTNETLINK +struct sock *rtnl; + +unsigned long rtnl_wlockct; + +struct rtnetlink_link * rtnetlink_links[NPROTO]; + +#define _S 1 /* superuser privileges required */ +#define _X 2 /* exclusive access to tables required */ +#define _G 4 /* GET request */ + +static const int rtm_min[(RTM_MAX+1-RTM_BASE)/4] = +{ + NLMSG_LENGTH(sizeof(struct ifinfomsg)), + NLMSG_LENGTH(sizeof(struct ifaddrmsg)), + NLMSG_LENGTH(sizeof(struct rtmsg)), + NLMSG_LENGTH(sizeof(struct ndmsg)), + NLMSG_LENGTH(sizeof(struct rtmsg)), + NLMSG_LENGTH(sizeof(struct tcmsg)), + NLMSG_LENGTH(sizeof(struct tcmsg)), + NLMSG_LENGTH(sizeof(struct tcmsg)) +}; + +static const int rta_max[(RTM_MAX+1-RTM_BASE)/4] = +{ + IFLA_MAX, + IFA_MAX, + RTA_MAX, + NDA_MAX, + RTA_MAX, + TCA_MAX, + TCA_MAX, + TCA_MAX +}; + +void __rta_fill(struct sk_buff *skb, int attrtype, int attrlen, const void *data) +{ + struct rtattr *rta; + int size = RTA_LENGTH(attrlen); + + rta = (struct rtattr*)skb_put(skb, RTA_ALIGN(size)); + rta->rta_type = attrtype; + rta->rta_len = size; + memcpy(RTA_DATA(rta), data, attrlen); +} + +int rtnetlink_send(struct sk_buff *skb, u32 pid, unsigned group, int echo) +{ + int err = 0; + + NETLINK_CB(skb).dst_groups = group; + if (echo) + atomic_inc(&skb->users); + netlink_broadcast(rtnl, skb, pid, group, GFP_KERNEL); + if (echo) + err = netlink_unicast(rtnl, skb, pid, MSG_DONTWAIT); + return err; +} + +static int rtnetlink_fill_ifinfo(struct sk_buff *skb, struct device *dev, + int type, u32 pid, u32 seq, u32 change) +{ + struct ifinfomsg *r; + struct nlmsghdr *nlh; + unsigned char *b = skb->tail; + + nlh = NLMSG_PUT(skb, pid, seq, type, sizeof(*r)); + if (pid) nlh->nlmsg_flags |= NLM_F_MULTI; + r = NLMSG_DATA(nlh); + r->ifi_family = AF_UNSPEC; + r->ifi_type = dev->type; + r->ifi_index = dev->ifindex; + r->ifi_flags = dev->flags; + r->ifi_change = change; + + RTA_PUT(skb, IFLA_IFNAME, strlen(dev->name)+1, dev->name); + if (dev->addr_len) { + RTA_PUT(skb, IFLA_ADDRESS, dev->addr_len, dev->dev_addr); + RTA_PUT(skb, IFLA_BROADCAST, dev->addr_len, dev->broadcast); + } + if (1) { + unsigned mtu = dev->mtu; + RTA_PUT(skb, IFLA_MTU, sizeof(mtu), &mtu); + } + if (dev->ifindex != dev->iflink) + RTA_PUT(skb, IFLA_LINK, sizeof(int), &dev->iflink); + if (dev->qdisc_sleeping) + RTA_PUT(skb, IFLA_QDISC, + strlen(dev->qdisc_sleeping->ops->id) + 1, + dev->qdisc_sleeping->ops->id); + if (dev->get_stats) { + struct net_device_stats *stats = dev->get_stats(dev); + if (stats) + RTA_PUT(skb, IFLA_STATS, sizeof(*stats), stats); + } + nlh->nlmsg_len = skb->tail - b; + return skb->len; + +nlmsg_failure: +rtattr_failure: + skb_trim(skb, b - skb->data); + return -1; +} + +int rtnetlink_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb) +{ + int idx; + int s_idx = cb->args[0]; + struct device *dev; + + for (dev=dev_base, idx=0; dev; dev = dev->next, idx++) { + if (idx < s_idx) + continue; + if (rtnetlink_fill_ifinfo(skb, dev, RTM_NEWLINK, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq, 0) <= 0) + break; + } + cb->args[0] = idx; + + return skb->len; +} + +int rtnetlink_dump_all(struct sk_buff *skb, struct netlink_callback *cb) +{ + int idx; + int s_idx = cb->family; + + if (s_idx == 0) + s_idx = 1; + for (idx=1; idx<NPROTO; idx++) { + int type = cb->nlh->nlmsg_type-RTM_BASE; + if (idx < s_idx || idx == PF_PACKET) + continue; + if (rtnetlink_links[idx] == NULL || + rtnetlink_links[idx][type].dumpit == NULL) + continue; + if (idx > s_idx) + memset(&cb->args[0], 0, sizeof(cb->args)); + if (rtnetlink_links[idx][type].dumpit(skb, cb) == 0) + continue; + if (skb_tailroom(skb) < 256) + break; + } + cb->family = idx; + + return skb->len; +} + +void rtmsg_ifinfo(int type, struct device *dev) +{ + struct sk_buff *skb; + int size = NLMSG_GOODSIZE; + + skb = alloc_skb(size, GFP_KERNEL); + if (!skb) + return; + + if (rtnetlink_fill_ifinfo(skb, dev, type, 0, 0, ~0U) < 0) { + kfree_skb(skb); + return; + } + NETLINK_CB(skb).dst_groups = RTMGRP_LINK; + netlink_broadcast(rtnl, skb, 0, RTMGRP_LINK, GFP_KERNEL); +} + +static int rtnetlink_done(struct netlink_callback *cb) +{ + if (cap_raised(NETLINK_CB(cb->skb).eff_cap, CAP_NET_ADMIN) && cb->nlh->nlmsg_flags&NLM_F_ATOMIC) + rtnl_shunlock(); + return 0; +} + +/* Process one rtnetlink message. */ + +extern __inline__ int +rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, int *errp) +{ + struct rtnetlink_link *link; + struct rtnetlink_link *link_tab; + struct rtattr *rta[RTATTR_MAX]; + + int exclusive = 0; + int sz_idx, kind; + int min_len; + int family; + int type; + int err; + + /* Only requests are handled by kernel now */ + if (!(nlh->nlmsg_flags&NLM_F_REQUEST)) + return 0; + + type = nlh->nlmsg_type; + + /* A control message: ignore them */ + if (type < RTM_BASE) + return 0; + + /* Unknown message: reply with EINVAL */ + if (type > RTM_MAX) + goto err_inval; + + type -= RTM_BASE; + + /* All the messages must have at least 1 byte length */ + if (nlh->nlmsg_len < NLMSG_LENGTH(sizeof(struct rtgenmsg))) + return 0; + + family = ((struct rtgenmsg*)NLMSG_DATA(nlh))->rtgen_family; + if (family > NPROTO) { + *errp = -EAFNOSUPPORT; + return -1; + } + + link_tab = rtnetlink_links[family]; + if (link_tab == NULL) + link_tab = rtnetlink_links[PF_UNSPEC]; + link = &link_tab[type]; + + sz_idx = type>>2; + kind = type&3; + + if (kind != 2 && !cap_raised(NETLINK_CB(skb).eff_cap, CAP_NET_ADMIN)) { + *errp = -EPERM; + return -1; + } + + if (kind == 2 && nlh->nlmsg_flags&NLM_F_DUMP) { + u32 rlen; + + if (link->dumpit == NULL) + link = &(rtnetlink_links[PF_UNSPEC][type]); + + if (link->dumpit == NULL) + goto err_inval; + + /* Super-user locks all the tables to get atomic snapshot */ + if (cap_raised(NETLINK_CB(skb).eff_cap, CAP_NET_ADMIN) + && nlh->nlmsg_flags&NLM_F_ATOMIC) + atomic_inc(&rtnl_rlockct); + if ((*errp = netlink_dump_start(rtnl, skb, nlh, + link->dumpit, + rtnetlink_done)) != 0) { + if (cap_raised(NETLINK_CB(skb).eff_cap, CAP_NET_ADMIN) && nlh->nlmsg_flags&NLM_F_ATOMIC) + atomic_dec(&rtnl_rlockct); + return -1; + } + rlen = NLMSG_ALIGN(nlh->nlmsg_len); + if (rlen > skb->len) + rlen = skb->len; + skb_pull(skb, rlen); + return -1; + } + + if (kind != 2) { + if (rtnl_exlock_nowait()) { + *errp = 0; + return -1; + } + exclusive = 1; + } + + memset(&rta, 0, sizeof(rta)); + + min_len = rtm_min[sz_idx]; + if (nlh->nlmsg_len < min_len) + goto err_inval; + + if (nlh->nlmsg_len > min_len) { + int attrlen = nlh->nlmsg_len - NLMSG_ALIGN(min_len); + struct rtattr *attr = (void*)nlh + NLMSG_ALIGN(min_len); + + while (RTA_OK(attr, attrlen)) { + unsigned flavor = attr->rta_type; + if (flavor) { + if (flavor > rta_max[sz_idx]) + goto err_inval; + rta[flavor-1] = attr; + } + attr = RTA_NEXT(attr, attrlen); + } + } + + if (link->doit == NULL) + link = &(rtnetlink_links[PF_UNSPEC][type]); + if (link->doit == NULL) + goto err_inval; + err = link->doit(skb, nlh, (void *)&rta); + + if (exclusive) + rtnl_exunlock(); + *errp = err; + return err; + +err_inval: + if (exclusive) + rtnl_exunlock(); + *errp = -EINVAL; + return -1; +} + +/* + * Process one packet of messages. + * Malformed skbs with wrong lengths of messages are discarded silently. + */ + +extern __inline__ int rtnetlink_rcv_skb(struct sk_buff *skb) +{ + int err; + struct nlmsghdr * nlh; + + while (skb->len >= NLMSG_SPACE(0)) { + u32 rlen; + + nlh = (struct nlmsghdr *)skb->data; + if (nlh->nlmsg_len < sizeof(*nlh) || skb->len < nlh->nlmsg_len) + return 0; + rlen = NLMSG_ALIGN(nlh->nlmsg_len); + if (rlen > skb->len) + rlen = skb->len; + if (rtnetlink_rcv_msg(skb, nlh, &err)) { + /* Not error, but we must interrupt processing here: + * Note, that in this case we do not pull message + * from skb, it will be processed later. + */ + if (err == 0) + return -1; + netlink_ack(skb, nlh, err); + } else if (nlh->nlmsg_flags&NLM_F_ACK) + netlink_ack(skb, nlh, 0); + skb_pull(skb, rlen); + } + + return 0; +} + +/* + * rtnetlink input queue processing routine: + * - try to acquire shared lock. If it is failed, defer processing. + * - feed skbs to rtnetlink_rcv_skb, until it refuse a message, + * that will occur, when a dump started and/or acquisition of + * exclusive lock failed. + */ + +static void rtnetlink_rcv(struct sock *sk, int len) +{ + struct sk_buff *skb; + + if (rtnl_shlock_nowait()) + return; + + while ((skb = skb_dequeue(&sk->receive_queue)) != NULL) { + if (rtnetlink_rcv_skb(skb)) { + if (skb->len) + skb_queue_head(&sk->receive_queue, skb); + else + kfree_skb(skb); + break; + } + kfree_skb(skb); + } + + rtnl_shunlock(); +} + +static struct rtnetlink_link link_rtnetlink_table[RTM_MAX-RTM_BASE+1] = +{ + { NULL, NULL, }, + { NULL, NULL, }, + { NULL, rtnetlink_dump_ifinfo, }, + { NULL, NULL, }, + + { NULL, NULL, }, + { NULL, NULL, }, + { NULL, rtnetlink_dump_all, }, + { NULL, NULL, }, + + { NULL, NULL, }, + { NULL, NULL, }, + { NULL, rtnetlink_dump_all, }, + { NULL, NULL, }, + + { neigh_add, NULL, }, + { neigh_delete, NULL, }, + { NULL, neigh_dump_info, }, + { NULL, NULL, }, + + { NULL, NULL, }, + { NULL, NULL, }, + { NULL, NULL, }, + { NULL, NULL, }, +}; + + +static int rtnetlink_event(struct notifier_block *this, unsigned long event, void *ptr) +{ + struct device *dev = ptr; + switch (event) { + case NETDEV_UNREGISTER: + rtmsg_ifinfo(RTM_DELLINK, dev); + break; + default: + rtmsg_ifinfo(RTM_NEWLINK, dev); + break; + } + return NOTIFY_DONE; +} + +struct notifier_block rtnetlink_dev_notifier = { + rtnetlink_event, + NULL, + 0 +}; + + +__initfunc(void rtnetlink_init(void)) +{ +#ifdef RTNL_DEBUG + printk("Initializing RT netlink socket\n"); +#endif + rtnl = netlink_kernel_create(NETLINK_ROUTE, rtnetlink_rcv); + if (rtnl == NULL) + panic("rtnetlink_init: cannot initialize rtnetlink\n"); + register_netdevice_notifier(&rtnetlink_dev_notifier); + rtnetlink_links[PF_UNSPEC] = link_rtnetlink_table; + rtnetlink_links[PF_PACKET] = link_rtnetlink_table; +} + + + +#endif |