Commit c0a645a7 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge branch 'fix-inefficiences-and-rename-nla_strlcpy' 

Francis Laniel says:

====================
Fix inefficiences and rename nla_strlcpy

This patch set answers to first three issues listed in:
https://github.com/KSPP/linux/issues/110

To sum up, the patch contributions are the following:
1. the first patch fixes an inefficiency where some bytes in dst were written
twice, one with 0 the other with src content.
2. The second one modifies nla_strlcpy to return the same value as strscpy,
i.e. number of bytes written or -E2BIG if src was truncated.
It also modifies code that calls nla_strlcpy and checks for its return value.
3. The third renames nla_strlcpy to nla_strscpy.

Unfortunately, I did not find how to create struct nlattr objects so I tested
my modifications on simple char* and with GDB using tc to get to
tcf_proto_check_kind.
====================

Link: https://lore.kernel.org/r/20201115170806.3578-1-laniel_francis@privacyrequired.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents 41294e6a 872f6903

drivers/infiniband/core/nldev.c

+5 −5
Original line number Diff line number Diff line
@@ -932,7 +932,7 @@ static int nldev_set_doit(struct sk_buff *skb, struct nlmsghdr *nlh, 
	if (tb[RDMA_NLDEV_ATTR_DEV_NAME]) {

		char name[IB_DEVICE_NAME_MAX] = {};



		nla_strlcpy(name, tb[RDMA_NLDEV_ATTR_DEV_NAME],

		nla_strscpy(name, tb[RDMA_NLDEV_ATTR_DEV_NAME],

			    IB_DEVICE_NAME_MAX);

		if (strlen(name) == 0) {

			err = -EINVAL;
@@ -1529,13 +1529,13 @@ static int nldev_newlink(struct sk_buff *skb, struct nlmsghdr *nlh, 
	    !tb[RDMA_NLDEV_ATTR_LINK_TYPE] || !tb[RDMA_NLDEV_ATTR_NDEV_NAME])

		return -EINVAL;



	nla_strlcpy(ibdev_name, tb[RDMA_NLDEV_ATTR_DEV_NAME],

	nla_strscpy(ibdev_name, tb[RDMA_NLDEV_ATTR_DEV_NAME],

		    sizeof(ibdev_name));

	if (strchr(ibdev_name, '%') || strlen(ibdev_name) == 0)

		return -EINVAL;



	nla_strlcpy(type, tb[RDMA_NLDEV_ATTR_LINK_TYPE], sizeof(type));

	nla_strlcpy(ndev_name, tb[RDMA_NLDEV_ATTR_NDEV_NAME],

	nla_strscpy(type, tb[RDMA_NLDEV_ATTR_LINK_TYPE], sizeof(type));

	nla_strscpy(ndev_name, tb[RDMA_NLDEV_ATTR_NDEV_NAME],

		    sizeof(ndev_name));



	ndev = dev_get_by_name(sock_net(skb->sk), ndev_name);
@@ -1602,7 +1602,7 @@ static int nldev_get_chardev(struct sk_buff *skb, struct nlmsghdr *nlh, 
	if (err || !tb[RDMA_NLDEV_ATTR_CHARDEV_TYPE])

		return -EINVAL;



	nla_strlcpy(client_name, tb[RDMA_NLDEV_ATTR_CHARDEV_TYPE],

	nla_strscpy(client_name, tb[RDMA_NLDEV_ATTR_CHARDEV_TYPE],

		    sizeof(client_name));



	if (tb[RDMA_NLDEV_ATTR_DEV_INDEX]) {

drivers/net/can/vxcan.c

+2 −2
Original line number Diff line number Diff line
@@ -186,7 +186,7 @@ static int vxcan_newlink(struct net *net, struct net_device *dev, 
	}



	if (ifmp && tbp[IFLA_IFNAME]) {

		nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);

		nla_strscpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);

		name_assign_type = NET_NAME_USER;

	} else {

		snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
@@ -223,7 +223,7 @@ static int vxcan_newlink(struct net *net, struct net_device *dev, 


	/* register first device */

	if (tb[IFLA_IFNAME])

		nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);

		nla_strscpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);

	else

		snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");

drivers/net/veth.c

+2 −2
Original line number Diff line number Diff line
@@ -1329,7 +1329,7 @@ static int veth_newlink(struct net *src_net, struct net_device *dev, 
	}



	if (ifmp && tbp[IFLA_IFNAME]) {

		nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);

		nla_strscpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);

		name_assign_type = NET_NAME_USER;

	} else {

		snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
@@ -1379,7 +1379,7 @@ static int veth_newlink(struct net *src_net, struct net_device *dev, 
		eth_hw_addr_random(dev);



	if (tb[IFLA_IFNAME])

		nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);

		nla_strscpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);

	else

		snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");

include/linux/genl_magic_struct.h

+1 −1
Original line number Diff line number Diff line
@@ -89,7 +89,7 @@ static inline int nla_put_u64_0pad(struct sk_buff *skb, int attrtype, u64 value) 
			nla_get_u64, nla_put_u64_0pad, false)

#define __str_field(attr_nr, attr_flag, name, maxlen) \

	__array(attr_nr, attr_flag, name, NLA_NUL_STRING, char, maxlen, \

			nla_strlcpy, nla_put, false)

			nla_strscpy, nla_put, false)

#define __bin_field(attr_nr, attr_flag, name, maxlen) \

	__array(attr_nr, attr_flag, name, NLA_BINARY, char, maxlen, \

			nla_memcpy, nla_put, false)

include/net/netlink.h

+2 −2
Original line number Diff line number Diff line
@@ -142,7 +142,7 @@ 
 * Attribute Misc:

 *   nla_memcpy(dest, nla, count)	copy attribute into memory

 *   nla_memcmp(nla, data, size)	compare attribute with memory area

 *   nla_strlcpy(dst, nla, size)	copy attribute to a sized string

 *   nla_strscpy(dst, nla, size)	copy attribute to a sized string

 *   nla_strcmp(nla, str)		compare attribute with string

 *

 * Attribute Parsing:
@@ -506,7 +506,7 @@ int __nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head, 
		struct netlink_ext_ack *extack);

int nla_policy_len(const struct nla_policy *, int);

struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype);

size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize);

ssize_t nla_strscpy(char *dst, const struct nlattr *nla, size_t dstsize);

char *nla_strdup(const struct nlattr *nla, gfp_t flags);

int nla_memcpy(void *dest, const struct nlattr *src, int count);

int nla_memcmp(const struct nlattr *nla, const void *data, size_t size);

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