[PATCH 4/5] [AFS]: Replace rtnetlink client by direct dev_base walking
From: David Howells
Date: Thu May 03 2007 - 05:54:49 EST
Replace the large and complicated rtnetlink client by two simple
functions for getting the MAC address for the first ethernet device
and building a list of IPv4 addresses.
Signed-off-by: Patrick McHardy <kaber@xxxxxxxxx>
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---
fs/afs/Makefile | 2
fs/afs/internal.h | 1
fs/afs/netdevices.c | 54 +++++
fs/afs/use-rtnetlink.c | 473 ------------------------------------------------
4 files changed, 55 insertions(+), 475 deletions(-)
diff --git a/fs/afs/Makefile b/fs/afs/Makefile
index 01545eb..cf83e5d 100644
--- a/fs/afs/Makefile
+++ b/fs/afs/Makefile
@@ -18,7 +18,7 @@ kafs-objs := \
security.o \
server.o \
super.o \
- use-rtnetlink.o \
+ netdevices.o \
vlclient.o \
vlocation.o \
vnode.o \
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 3363e31..551db89 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -349,7 +349,6 @@ struct afs_permits {
* 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 */
diff --git a/fs/afs/netdevices.c b/fs/afs/netdevices.c
new file mode 100644
index 0000000..2b30873
--- /dev/null
+++ b/fs/afs/netdevices.c
@@ -0,0 +1,54 @@
+/* AFS network device helpers
+ *
+ * Copyright (c) 2007 Patrick McHardy <kaber@xxxxxxxxx>
+ */
+
+#include <linux/string.h>
+#include <linux/rtnetlink.h>
+#include <linux/inetdevice.h>
+#include <linux/netdevice.h>
+#include <linux/if_arp.h>
+#include "internal.h"
+
+int afs_get_MAC_address(u8 mac[ETH_ALEN])
+{
+ struct net_device *dev;
+ int ret = -ENODEV;
+
+ rtnl_lock();
+ dev = __dev_getfirstbyhwtype(ARPHRD_ETHER);
+ if (dev) {
+ memcpy(mac, dev->dev_addr, ETH_ALEN);
+ ret = 0;
+ }
+ rtnl_unlock();
+ return ret;
+}
+
+int afs_get_ipv4_interfaces(struct afs_interface *bufs, size_t maxbufs,
+ bool wantloopback)
+{
+ struct net_device *dev;
+ struct in_device *idev;
+ int n = 0;
+
+ rtnl_lock();
+ for (dev = dev_base; dev; dev = dev->next) {
+ if (dev->type == ARPHRD_LOOPBACK && !wantloopback)
+ continue;
+ idev = __in_dev_get_rtnl(dev);
+ if (!idev)
+ continue;
+ for_primary_ifa(idev) {
+ if (n == maxbufs)
+ goto out;
+ bufs[n].address.s_addr = ifa->ifa_address;
+ bufs[n].netmask.s_addr = ifa->ifa_mask;
+ bufs[n].mtu = dev->mtu;
+ n++;
+ } endfor_ifa(idev)
+ }
+out:
+ rtnl_unlock();
+ return n;
+}
diff --git a/fs/afs/use-rtnetlink.c b/fs/afs/use-rtnetlink.c
deleted file mode 100644
index f8991c7..0000000
--- a/fs/afs/use-rtnetlink.c
+++ /dev/null
@@ -1,473 +0,0 @@
-/* RTNETLINK client
- *
- * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
- * Written by David Howells (dhowells@xxxxxxxxxx)
- *
- * 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 <linux/netlink.h>
-#include <linux/rtnetlink.h>
-#include <linux/if_addr.h>
-#include <linux/if_arp.h>
-#include <linux/inetdevice.h>
-#include <net/netlink.h>
-#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(" = %zd [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;
-}
-
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