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authorRichard Alpe <richard.alpe@ericsson.com>2015-02-09 11:50:04 +0300
committerDavid S. Miller <davem@davemloft.net>2015-02-10 00:20:47 +0300
commitd0796d1ef63deb38147729664691ba3090930b26 (patch)
treeb227569cf4d6cd2250000095f1a1867f86d08854 /net/tipc/netlink_compat.c
parentbfb3e5dd8dfd84dfd13649393abab63e43267b00 (diff)
downloadlinux-d0796d1ef63deb38147729664691ba3090930b26.tar.xz
tipc: convert legacy nl bearer dump to nl compat
Introduce a framework for dumping netlink data from the new netlink API and formatting it to the old legacy API format. This is done by looping the dump data and calling a format handler for each entity, in this case a bearer. We dump until either all data is dumped or we reach the limited buffer size of the legacy API. Remember, the legacy API doesn't scale. In this commit we convert TIPC_CMD_GET_BEARER_NAMES to use the compat layer. Signed-off-by: Richard Alpe <richard.alpe@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/tipc/netlink_compat.c')
-rw-r--r--net/tipc/netlink_compat.c274
1 files changed, 273 insertions, 1 deletions
diff --git a/net/tipc/netlink_compat.c b/net/tipc/netlink_compat.c
index f752854c8b10..bd75ea290e3a 100644
--- a/net/tipc/netlink_compat.c
+++ b/net/tipc/netlink_compat.c
@@ -33,9 +33,265 @@
#include "core.h"
#include "config.h"
+#include "bearer.h"
#include <net/genetlink.h>
#include <linux/tipc_config.h>
+/* The legacy API had an artificial message length limit called
+ * ULTRA_STRING_MAX_LEN.
+ */
+#define ULTRA_STRING_MAX_LEN 32768
+
+#define TIPC_SKB_MAX TLV_SPACE(ULTRA_STRING_MAX_LEN)
+
+#define REPLY_TRUNCATED "<truncated>\n"
+
+struct tipc_nl_compat_msg {
+ u16 cmd;
+ int rep_size;
+ struct sk_buff *rep;
+ struct tlv_desc *req;
+ struct sock *dst_sk;
+};
+
+struct tipc_nl_compat_cmd_dump {
+ int (*dumpit)(struct sk_buff *, struct netlink_callback *);
+ int (*format)(struct tipc_nl_compat_msg *msg, struct nlattr **attrs);
+};
+
+static int tipc_skb_tailroom(struct sk_buff *skb)
+{
+ int tailroom;
+ int limit;
+
+ tailroom = skb_tailroom(skb);
+ limit = TIPC_SKB_MAX - skb->len;
+
+ if (tailroom < limit)
+ return tailroom;
+
+ return limit;
+}
+
+static int tipc_add_tlv(struct sk_buff *skb, u16 type, void *data, u16 len)
+{
+ struct tlv_desc *tlv = (struct tlv_desc *)skb_tail_pointer(skb);
+
+ if (tipc_skb_tailroom(skb) < TLV_SPACE(len))
+ return -EMSGSIZE;
+
+ skb_put(skb, TLV_SPACE(len));
+ tlv->tlv_type = htons(type);
+ tlv->tlv_len = htons(TLV_LENGTH(len));
+ if (len && data)
+ memcpy(TLV_DATA(tlv), data, len);
+
+ return 0;
+}
+
+static struct sk_buff *tipc_tlv_alloc(int size)
+{
+ int hdr_len;
+ struct sk_buff *buf;
+
+ size = TLV_SPACE(size);
+ hdr_len = nlmsg_total_size(GENL_HDRLEN + TIPC_GENL_HDRLEN);
+
+ buf = alloc_skb(hdr_len + size, GFP_KERNEL);
+ if (!buf)
+ return NULL;
+
+ skb_reserve(buf, hdr_len);
+
+ return buf;
+}
+
+static struct sk_buff *tipc_get_err_tlv(char *str)
+{
+ int str_len = strlen(str) + 1;
+ struct sk_buff *buf;
+
+ buf = tipc_tlv_alloc(TLV_SPACE(str_len));
+ if (buf)
+ tipc_add_tlv(buf, TIPC_TLV_ERROR_STRING, str, str_len);
+
+ return buf;
+}
+
+static int __tipc_nl_compat_dumpit(struct tipc_nl_compat_cmd_dump *cmd,
+ struct tipc_nl_compat_msg *msg,
+ struct sk_buff *arg)
+{
+ int len = 0;
+ int err;
+ struct sk_buff *buf;
+ struct nlmsghdr *nlmsg;
+ struct netlink_callback cb;
+
+ memset(&cb, 0, sizeof(cb));
+ cb.nlh = (struct nlmsghdr *)arg->data;
+ cb.skb = arg;
+
+ buf = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ buf->sk = msg->dst_sk;
+
+ do {
+ int rem;
+
+ len = (*cmd->dumpit)(buf, &cb);
+
+ nlmsg_for_each_msg(nlmsg, nlmsg_hdr(buf), len, rem) {
+ struct nlattr **attrs;
+
+ err = tipc_nlmsg_parse(nlmsg, &attrs);
+ if (err)
+ goto err_out;
+
+ err = (*cmd->format)(msg, attrs);
+ if (err)
+ goto err_out;
+
+ if (tipc_skb_tailroom(msg->rep) <= 1) {
+ err = -EMSGSIZE;
+ goto err_out;
+ }
+ }
+
+ skb_reset_tail_pointer(buf);
+ buf->len = 0;
+
+ } while (len);
+
+ err = 0;
+
+err_out:
+ kfree_skb(buf);
+
+ if (err == -EMSGSIZE) {
+ /* The legacy API only considered messages filling
+ * "ULTRA_STRING_MAX_LEN" to be truncated.
+ */
+ if ((TIPC_SKB_MAX - msg->rep->len) <= 1) {
+ char *tail = skb_tail_pointer(msg->rep);
+
+ if (*tail != '\0')
+ sprintf(tail - sizeof(REPLY_TRUNCATED) - 1,
+ REPLY_TRUNCATED);
+ }
+
+ return 0;
+ }
+
+ return err;
+}
+
+static int tipc_nl_compat_dumpit(struct tipc_nl_compat_cmd_dump *cmd,
+ struct tipc_nl_compat_msg *msg)
+{
+ int err;
+ struct sk_buff *arg;
+
+ msg->rep = tipc_tlv_alloc(msg->rep_size);
+ if (!msg->rep)
+ return -ENOMEM;
+
+ arg = nlmsg_new(0, GFP_KERNEL);
+ if (!arg) {
+ kfree_skb(msg->rep);
+ return -ENOMEM;
+ }
+
+ err = __tipc_nl_compat_dumpit(cmd, msg, arg);
+ if (err)
+ kfree_skb(msg->rep);
+
+ kfree_skb(arg);
+
+ return err;
+}
+
+static int tipc_nl_compat_bearer_dump(struct tipc_nl_compat_msg *msg,
+ struct nlattr **attrs)
+{
+ struct nlattr *bearer[TIPC_NLA_BEARER_MAX + 1];
+
+ nla_parse_nested(bearer, TIPC_NLA_BEARER_MAX, attrs[TIPC_NLA_BEARER],
+ NULL);
+
+ return tipc_add_tlv(msg->rep, TIPC_TLV_BEARER_NAME,
+ nla_data(bearer[TIPC_NLA_BEARER_NAME]),
+ nla_len(bearer[TIPC_NLA_BEARER_NAME]));
+}
+
+static int tipc_nl_compat_handle(struct tipc_nl_compat_msg *msg)
+{
+ struct tipc_nl_compat_cmd_dump dump;
+
+ memset(&dump, 0, sizeof(dump));
+
+ switch (msg->cmd) {
+ case TIPC_CMD_GET_BEARER_NAMES:
+ msg->rep_size = MAX_BEARERS * TLV_SPACE(TIPC_MAX_BEARER_NAME);
+ dump.dumpit = tipc_nl_bearer_dump;
+ dump.format = tipc_nl_compat_bearer_dump;
+ return tipc_nl_compat_dumpit(&dump, msg);
+ }
+
+ return -EOPNOTSUPP;
+}
+
+static int tipc_nl_compat_recv(struct sk_buff *skb, struct genl_info *info)
+{
+ int err;
+ int len;
+ struct tipc_nl_compat_msg msg;
+ struct nlmsghdr *req_nlh;
+ struct nlmsghdr *rep_nlh;
+ struct tipc_genlmsghdr *req_userhdr = info->userhdr;
+ struct net *net = genl_info_net(info);
+
+ memset(&msg, 0, sizeof(msg));
+
+ req_nlh = (struct nlmsghdr *)skb->data;
+ msg.req = nlmsg_data(req_nlh) + GENL_HDRLEN + TIPC_GENL_HDRLEN;
+ msg.cmd = req_userhdr->cmd;
+ msg.dst_sk = info->dst_sk;
+
+ if ((msg.cmd & 0xC000) && (!netlink_net_capable(skb, CAP_NET_ADMIN))) {
+ msg.rep = tipc_get_err_tlv(TIPC_CFG_NOT_NET_ADMIN);
+ err = -EACCES;
+ goto send;
+ }
+
+ len = nlmsg_attrlen(req_nlh, GENL_HDRLEN + TIPC_GENL_HDRLEN);
+ if (TLV_GET_LEN(msg.req) && !TLV_OK(msg.req, len)) {
+ msg.rep = tipc_get_err_tlv(TIPC_CFG_NOT_SUPPORTED);
+ err = -EOPNOTSUPP;
+ goto send;
+ }
+
+ err = tipc_nl_compat_handle(&msg);
+ if (err == -EOPNOTSUPP)
+ msg.rep = tipc_get_err_tlv(TIPC_CFG_NOT_SUPPORTED);
+ else if (err == -EINVAL)
+ msg.rep = tipc_get_err_tlv(TIPC_CFG_TLV_ERROR);
+send:
+ if (!msg.rep)
+ return err;
+
+ len = nlmsg_total_size(GENL_HDRLEN + TIPC_GENL_HDRLEN);
+ skb_push(msg.rep, len);
+ rep_nlh = nlmsg_hdr(msg.rep);
+ memcpy(rep_nlh, info->nlhdr, len);
+ rep_nlh->nlmsg_len = msg.rep->len;
+ genlmsg_unicast(net, msg.rep, NETLINK_CB(skb).portid);
+
+ return err;
+}
+
static int handle_cmd(struct sk_buff *skb, struct genl_info *info)
{
struct net *net = genl_info_net(info);
@@ -69,6 +325,22 @@ static int handle_cmd(struct sk_buff *skb, struct genl_info *info)
return 0;
}
+/* Temporary function to keep functionality throughout the patchset
+ * without having to mess with the global variables and other trickery
+ * of the old API.
+ */
+static int tipc_nl_compat_tmp_wrap(struct sk_buff *skb, struct genl_info *info)
+{
+ struct tipc_genlmsghdr *req = info->userhdr;
+
+ switch (req->cmd) {
+ case TIPC_CMD_GET_BEARER_NAMES:
+ return tipc_nl_compat_recv(skb, info);
+ }
+
+ return handle_cmd(skb, info);
+}
+
static struct genl_family tipc_genl_compat_family = {
.id = GENL_ID_GENERATE,
.name = TIPC_GENL_NAME,
@@ -81,7 +353,7 @@ static struct genl_family tipc_genl_compat_family = {
static struct genl_ops tipc_genl_compat_ops[] = {
{
.cmd = TIPC_GENL_CMD,
- .doit = handle_cmd,
+ .doit = tipc_nl_compat_tmp_wrap,
},
};