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inet: introduce inet->inet_flags
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Various inet fields are currently racy.

do_ip_setsockopt() and do_ip_getsockopt() are mostly holding
the socket lock, but some (fast) paths do not.

Use a new inet->inet_flags to hold atomic bits in the series.

Remove inet->cmsg_flags, and use instead 9 bits from inet_flags.

Signed-off-by: Eric Dumazet <[email protected]>
Acked-by: Soheil Hassas Yeganeh <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
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@davem330
Eric Dumazet authored and davem330 committed Aug 16, 2023
1 parent 936db83 commit c274af2
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Showing 8 changed files with 83 additions and 71 deletions.
55 changes: 44 additions & 11 deletions include/net/inet_sock.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -194,6 +194,7 @@ struct rtable;
* @inet_rcv_saddr - Bound local IPv4 addr
* @inet_dport - Destination port
* @inet_num - Local port
* @inet_flags - various atomic flags
* @inet_saddr - Sending source
* @uc_ttl - Unicast TTL
* @inet_sport - Source port
Expand All @@ -218,11 +219,11 @@ struct inet_sock {
#define inet_dport sk.__sk_common.skc_dport
#define inet_num sk.__sk_common.skc_num

unsigned long inet_flags;
__be32 inet_saddr;
__s16 uc_ttl;
__u16 cmsg_flags;
struct ip_options_rcu __rcu *inet_opt;
__be16 inet_sport;
struct ip_options_rcu __rcu *inet_opt;
__u16 inet_id;

__u8 tos;
Expand Down Expand Up @@ -259,16 +260,48 @@ struct inet_sock {
#define IPCORK_OPT 1 /* ip-options has been held in ipcork.opt */
#define IPCORK_ALLFRAG 2 /* always fragment (for ipv6 for now) */

enum {
INET_FLAGS_PKTINFO = 0,
INET_FLAGS_TTL = 1,
INET_FLAGS_TOS = 2,
INET_FLAGS_RECVOPTS = 3,
INET_FLAGS_RETOPTS = 4,
INET_FLAGS_PASSSEC = 5,
INET_FLAGS_ORIGDSTADDR = 6,
INET_FLAGS_CHECKSUM = 7,
INET_FLAGS_RECVFRAGSIZE = 8,
};

/* cmsg flags for inet */
#define IP_CMSG_PKTINFO BIT(0)
#define IP_CMSG_TTL BIT(1)
#define IP_CMSG_TOS BIT(2)
#define IP_CMSG_RECVOPTS BIT(3)
#define IP_CMSG_RETOPTS BIT(4)
#define IP_CMSG_PASSSEC BIT(5)
#define IP_CMSG_ORIGDSTADDR BIT(6)
#define IP_CMSG_CHECKSUM BIT(7)
#define IP_CMSG_RECVFRAGSIZE BIT(8)
#define IP_CMSG_PKTINFO BIT(INET_FLAGS_PKTINFO)
#define IP_CMSG_TTL BIT(INET_FLAGS_TTL)
#define IP_CMSG_TOS BIT(INET_FLAGS_TOS)
#define IP_CMSG_RECVOPTS BIT(INET_FLAGS_RECVOPTS)
#define IP_CMSG_RETOPTS BIT(INET_FLAGS_RETOPTS)
#define IP_CMSG_PASSSEC BIT(INET_FLAGS_PASSSEC)
#define IP_CMSG_ORIGDSTADDR BIT(INET_FLAGS_ORIGDSTADDR)
#define IP_CMSG_CHECKSUM BIT(INET_FLAGS_CHECKSUM)
#define IP_CMSG_RECVFRAGSIZE BIT(INET_FLAGS_RECVFRAGSIZE)

#define IP_CMSG_ALL (IP_CMSG_PKTINFO | IP_CMSG_TTL | \
IP_CMSG_TOS | IP_CMSG_RECVOPTS | \
IP_CMSG_RETOPTS | IP_CMSG_PASSSEC | \
IP_CMSG_ORIGDSTADDR | IP_CMSG_CHECKSUM | \
IP_CMSG_RECVFRAGSIZE)

static inline unsigned long inet_cmsg_flags(const struct inet_sock *inet)
{
return READ_ONCE(inet->inet_flags) & IP_CMSG_ALL;
}

#define inet_test_bit(nr, sk) \
test_bit(INET_FLAGS_##nr, &inet_sk(sk)->inet_flags)
#define inet_set_bit(nr, sk) \
set_bit(INET_FLAGS_##nr, &inet_sk(sk)->inet_flags)
#define inet_clear_bit(nr, sk) \
clear_bit(INET_FLAGS_##nr, &inet_sk(sk)->inet_flags)
#define inet_assign_bit(nr, sk, val) \
assign_bit(INET_FLAGS_##nr, &inet_sk(sk)->inet_flags, val)

static inline bool sk_is_inet(struct sock *sk)
{
Expand Down
84 changes: 31 additions & 53 deletions net/ipv4/ip_sockglue.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -171,8 +171,10 @@ static void ip_cmsg_recv_dstaddr(struct msghdr *msg, struct sk_buff *skb)
void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk,
struct sk_buff *skb, int tlen, int offset)
{
struct inet_sock *inet = inet_sk(sk);
unsigned int flags = inet->cmsg_flags;
unsigned long flags = inet_cmsg_flags(inet_sk(sk));

if (!flags)
return;

/* Ordered by supposed usage frequency */
if (flags & IP_CMSG_PKTINFO) {
Expand Down Expand Up @@ -568,7 +570,7 @@ int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
if (ipv4_datagram_support_cmsg(sk, skb, serr->ee.ee_origin)) {
sin->sin_family = AF_INET;
sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
if (inet_sk(sk)->cmsg_flags)
if (inet_cmsg_flags(inet_sk(sk)))
ip_cmsg_recv(msg, skb);
}

Expand Down Expand Up @@ -635,7 +637,7 @@ EXPORT_SYMBOL(ip_sock_set_mtu_discover);
void ip_sock_set_pktinfo(struct sock *sk)
{
lock_sock(sk);
inet_sk(sk)->cmsg_flags |= IP_CMSG_PKTINFO;
inet_set_bit(PKTINFO, sk);
release_sock(sk);
}
EXPORT_SYMBOL(ip_sock_set_pktinfo);
Expand Down Expand Up @@ -990,67 +992,43 @@ int do_ip_setsockopt(struct sock *sk, int level, int optname,
break;
}
case IP_PKTINFO:
if (val)
inet->cmsg_flags |= IP_CMSG_PKTINFO;
else
inet->cmsg_flags &= ~IP_CMSG_PKTINFO;
inet_assign_bit(PKTINFO, sk, val);
break;
case IP_RECVTTL:
if (val)
inet->cmsg_flags |= IP_CMSG_TTL;
else
inet->cmsg_flags &= ~IP_CMSG_TTL;
inet_assign_bit(TTL, sk, val);
break;
case IP_RECVTOS:
if (val)
inet->cmsg_flags |= IP_CMSG_TOS;
else
inet->cmsg_flags &= ~IP_CMSG_TOS;
inet_assign_bit(TOS, sk, val);
break;
case IP_RECVOPTS:
if (val)
inet->cmsg_flags |= IP_CMSG_RECVOPTS;
else
inet->cmsg_flags &= ~IP_CMSG_RECVOPTS;
inet_assign_bit(RECVOPTS, sk, val);
break;
case IP_RETOPTS:
if (val)
inet->cmsg_flags |= IP_CMSG_RETOPTS;
else
inet->cmsg_flags &= ~IP_CMSG_RETOPTS;
inet_assign_bit(RETOPTS, sk, val);
break;
case IP_PASSSEC:
if (val)
inet->cmsg_flags |= IP_CMSG_PASSSEC;
else
inet->cmsg_flags &= ~IP_CMSG_PASSSEC;
inet_assign_bit(PASSSEC, sk, val);
break;
case IP_RECVORIGDSTADDR:
if (val)
inet->cmsg_flags |= IP_CMSG_ORIGDSTADDR;
else
inet->cmsg_flags &= ~IP_CMSG_ORIGDSTADDR;
inet_assign_bit(ORIGDSTADDR, sk, val);
break;
case IP_CHECKSUM:
if (val) {
if (!(inet->cmsg_flags & IP_CMSG_CHECKSUM)) {
if (!(inet_test_bit(CHECKSUM, sk))) {
inet_inc_convert_csum(sk);
inet->cmsg_flags |= IP_CMSG_CHECKSUM;
inet_set_bit(CHECKSUM, sk);
}
} else {
if (inet->cmsg_flags & IP_CMSG_CHECKSUM) {
if (inet_test_bit(CHECKSUM, sk)) {
inet_dec_convert_csum(sk);
inet->cmsg_flags &= ~IP_CMSG_CHECKSUM;
inet_clear_bit(CHECKSUM, sk);
}
}
break;
case IP_RECVFRAGSIZE:
if (sk->sk_type != SOCK_RAW && sk->sk_type != SOCK_DGRAM)
goto e_inval;
if (val)
inet->cmsg_flags |= IP_CMSG_RECVFRAGSIZE;
else
inet->cmsg_flags &= ~IP_CMSG_RECVFRAGSIZE;
inet_assign_bit(RECVFRAGSIZE, sk, val);
break;
case IP_TOS: /* This sets both TOS and Precedence */
__ip_sock_set_tos(sk, val);
Expand Down Expand Up @@ -1415,7 +1393,7 @@ int do_ip_setsockopt(struct sock *sk, int level, int optname,
void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb)
{
struct in_pktinfo *pktinfo = PKTINFO_SKB_CB(skb);
bool prepare = (inet_sk(sk)->cmsg_flags & IP_CMSG_PKTINFO) ||
bool prepare = inet_test_bit(PKTINFO, sk) ||
ipv6_sk_rxinfo(sk);

if (prepare && skb_rtable(skb)) {
Expand Down Expand Up @@ -1601,31 +1579,31 @@ int do_ip_getsockopt(struct sock *sk, int level, int optname,
return 0;
}
case IP_PKTINFO:
val = (inet->cmsg_flags & IP_CMSG_PKTINFO) != 0;
val = inet_test_bit(PKTINFO, sk);
break;
case IP_RECVTTL:
val = (inet->cmsg_flags & IP_CMSG_TTL) != 0;
val = inet_test_bit(TTL, sk);
break;
case IP_RECVTOS:
val = (inet->cmsg_flags & IP_CMSG_TOS) != 0;
val = inet_test_bit(TOS, sk);
break;
case IP_RECVOPTS:
val = (inet->cmsg_flags & IP_CMSG_RECVOPTS) != 0;
val = inet_test_bit(RECVOPTS, sk);
break;
case IP_RETOPTS:
val = (inet->cmsg_flags & IP_CMSG_RETOPTS) != 0;
val = inet_test_bit(RETOPTS, sk);
break;
case IP_PASSSEC:
val = (inet->cmsg_flags & IP_CMSG_PASSSEC) != 0;
val = inet_test_bit(PASSSEC, sk);
break;
case IP_RECVORIGDSTADDR:
val = (inet->cmsg_flags & IP_CMSG_ORIGDSTADDR) != 0;
val = inet_test_bit(ORIGDSTADDR, sk);
break;
case IP_CHECKSUM:
val = (inet->cmsg_flags & IP_CMSG_CHECKSUM) != 0;
val = inet_test_bit(CHECKSUM, sk);
break;
case IP_RECVFRAGSIZE:
val = (inet->cmsg_flags & IP_CMSG_RECVFRAGSIZE) != 0;
val = inet_test_bit(RECVFRAGSIZE, sk);
break;
case IP_TOS:
val = inet->tos;
Expand Down Expand Up @@ -1737,19 +1715,19 @@ int do_ip_getsockopt(struct sock *sk, int level, int optname,
msg.msg_controllen = len;
msg.msg_flags = in_compat_syscall() ? MSG_CMSG_COMPAT : 0;

if (inet->cmsg_flags & IP_CMSG_PKTINFO) {
if (inet_test_bit(PKTINFO, sk)) {
struct in_pktinfo info;

info.ipi_addr.s_addr = inet->inet_rcv_saddr;
info.ipi_spec_dst.s_addr = inet->inet_rcv_saddr;
info.ipi_ifindex = inet->mc_index;
put_cmsg(&msg, SOL_IP, IP_PKTINFO, sizeof(info), &info);
}
if (inet->cmsg_flags & IP_CMSG_TTL) {
if (inet_test_bit(TTL, sk)) {
int hlim = inet->mc_ttl;
put_cmsg(&msg, SOL_IP, IP_TTL, sizeof(hlim), &hlim);
}
if (inet->cmsg_flags & IP_CMSG_TOS) {
if (inet_test_bit(TOS, sk)) {
int tos = inet->rcv_tos;
put_cmsg(&msg, SOL_IP, IP_TOS, sizeof(tos), &tos);
}
Expand Down
5 changes: 3 additions & 2 deletions net/ipv4/ping.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -894,7 +894,7 @@ int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int flags,
*addr_len = sizeof(*sin);
}

if (isk->cmsg_flags)
if (inet_cmsg_flags(isk))
ip_cmsg_recv(msg, skb);

#if IS_ENABLED(CONFIG_IPV6)
Expand All @@ -921,7 +921,8 @@ int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int flags,
if (skb->protocol == htons(ETH_P_IPV6) &&
inet6_sk(sk)->rxopt.all)
pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb);
else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags)
else if (skb->protocol == htons(ETH_P_IP) &&
inet_cmsg_flags(isk))
ip_cmsg_recv(msg, skb);
#endif
} else {
Expand Down
2 changes: 1 addition & 1 deletion net/ipv4/raw.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -767,7 +767,7 @@ static int raw_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
*addr_len = sizeof(*sin);
}
if (inet->cmsg_flags)
if (inet_cmsg_flags(inet))
ip_cmsg_recv(msg, skb);
if (flags & MSG_TRUNC)
copied = skb->len;
Expand Down
2 changes: 1 addition & 1 deletion net/ipv4/udp.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1870,7 +1870,7 @@ int udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int flags,
if (udp_sk(sk)->gro_enabled)
udp_cmsg_recv(msg, sk, skb);

if (inet->cmsg_flags)
if (inet_cmsg_flags(inet))
ip_cmsg_recv_offset(msg, sk, skb, sizeof(struct udphdr), off);

err = copied;
Expand Down
2 changes: 1 addition & 1 deletion net/ipv6/datagram.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -524,7 +524,7 @@ int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
} else {
ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
&sin->sin6_addr);
if (inet_sk(sk)->cmsg_flags)
if (inet_cmsg_flags(inet_sk(sk)))
ip_cmsg_recv(msg, skb);
}
}
Expand Down
2 changes: 1 addition & 1 deletion net/ipv6/udp.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -420,7 +420,7 @@ int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
ip6_datagram_recv_common_ctl(sk, msg, skb);

if (is_udp4) {
if (inet->cmsg_flags)
if (inet_cmsg_flags(inet))
ip_cmsg_recv_offset(msg, sk, skb,
sizeof(struct udphdr), off);
} else {
Expand Down
2 changes: 1 addition & 1 deletion net/l2tp/l2tp_ip.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -552,7 +552,7 @@ static int l2tp_ip_recvmsg(struct sock *sk, struct msghdr *msg,
memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
*addr_len = sizeof(*sin);
}
if (inet->cmsg_flags)
if (inet_cmsg_flags(inet))
ip_cmsg_recv(msg, skb);
if (flags & MSG_TRUNC)
copied = skb->len;
Expand Down

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