There are a number of places where we want to handle either a sockaddr_in
or a sockaddr_in6. In some of those we use a void *, which works ok and
matches some standard library interfaces, but doesn't give a signature
level hint that we're dealing with only sockaddr_in or sockaddr_in6, not
(say) sockaddr_un or another type of socket address. Other places we use a
sockaddr_storage, which also works, but has the same problem in addition to
allocating more on the stack than we need to.
Introduce union sockaddr_inany to explictly handle this case: it has
variants for sockaddr_in and sockaddr_in6. Use it in a number of
places where it's easy to do so.
Signed-off-by: David Gibson <david(a)gibson.dropbear.id.au>
---
icmp.c | 18 ++++++------------
inany.h | 33 +++++++++++++++++++++------------
tcp.c | 11 +++++------
tcp_splice.c | 2 +-
tcp_splice.h | 3 ++-
5 files changed, 35 insertions(+), 32 deletions(-)
diff --git a/icmp.c b/icmp.c
index faa38c81..fb2fcafc 100644
--- a/icmp.c
+++ b/icmp.c
@@ -36,6 +36,8 @@
#include "passt.h"
#include "tap.h"
#include "log.h"
+#include "siphash.h"
+#include "inany.h"
#include "icmp.h"
#define ICMP_ECHO_TIMEOUT 60 /* s, timeout for ICMP socket activity */
@@ -67,13 +69,9 @@ void icmp_sock_handler(const struct ctx *c, sa_family_t af, union
epoll_ref ref)
struct icmp_id_sock *const id_sock = af == AF_INET
? &icmp_id_map[V4][ref.icmp.id] : &icmp_id_map[V6][ref.icmp.id];
const char *const pname = af == AF_INET ? "ICMP" : "ICMPv6";
- char buf[USHRT_MAX];
- union {
- struct sockaddr sa;
- struct sockaddr_in sa4;
- struct sockaddr_in6 sa6;
- } sr;
+ union sockaddr_inany sr;
socklen_t sl = sizeof(sr);
+ char buf[USHRT_MAX];
uint16_t seq;
ssize_t n;
@@ -86,7 +84,7 @@ void icmp_sock_handler(const struct ctx *c, sa_family_t af, union
epoll_ref ref)
pname, strerror(errno));
return;
}
- if (sr.sa.sa_family != af)
+ if (sr.sa_family != af)
goto unexpected;
if (af == AF_INET) {
@@ -214,11 +212,7 @@ int icmp_tap_handler(const struct ctx *c, uint8_t pif, sa_family_t
af,
const struct pool *p, const struct timespec *now)
{
const char *const pname = af == AF_INET ? "ICMP" : "ICMPv6";
- union {
- struct sockaddr sa;
- struct sockaddr_in sa4;
- struct sockaddr_in6 sa6;
- } sa = { .sa.sa_family = af };
+ union sockaddr_inany sa = { .sa_family = af };
const socklen_t sl = af == AF_INET ? sizeof(sa.sa4) : sizeof(sa.sa6);
struct icmp_id_sock *id_sock;
uint16_t id, seq;
diff --git a/inany.h b/inany.h
index d08d1f33..474e09d0 100644
--- a/inany.h
+++ b/inany.h
@@ -9,6 +9,8 @@
#ifndef INANY_H
#define INANY_H
+struct siphash_state;
+
/** union inany_addr - Represents either an IPv4 or IPv6 address
* @a6: Address as an IPv6 address, may be IPv4-mapped
* @v4mapped.zero: All zero-bits for an IPv4 address
@@ -32,6 +34,19 @@ static_assert(sizeof(union inany_addr) == sizeof(struct in6_addr),
static_assert(_Alignof(union inany_addr) == _Alignof(uint32_t),
"union inany_addr has unexpected alignment");
+/** union sockaddr_inany - Either a sockaddr_in or a sockaddr_in6
+ * @sa_family: Address family, AF_INET or AF_INET6
+ * @sa: Plain struct sockaddr (useful to avoid casts)
+ * @sa4: IPv4 socket address, valid if sa_family == AF_INET
+ * @sa6: IPv6 socket address, valid if sa_family == AF_INET6
+ */
+union sockaddr_inany {
+ sa_family_t sa_family;
+ struct sockaddr sa;
+ struct sockaddr_in sa4;
+ struct sockaddr_in6 sa6;
+};
+
/** inany_v4 - Extract IPv4 address, if present, from IPv[46] address
* @addr: IPv4 or IPv6 address
*
@@ -91,23 +106,17 @@ static inline void inany_from_af(union inany_addr *aa,
/** inany_from_sockaddr - Extract IPv[46] address and port number from sockaddr
* @aa: Pointer to store IPv[46] address
* @port: Pointer to store port number, host order
- * @addr: struct sockaddr_in (IPv4) or struct sockaddr_in6 (IPv6)
+ * @addr: AF_INET or AF_INET6 socket address
*/
static inline void inany_from_sockaddr(union inany_addr *aa, in_port_t *port,
- const void *addr)
+ const union sockaddr_inany *sa)
{
- const struct sockaddr *sa = (const struct sockaddr *)addr;
-
if (sa->sa_family == AF_INET6) {
- struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)sa;
-
- inany_from_af(aa, AF_INET6, &sa6->sin6_addr);
- *port = ntohs(sa6->sin6_port);
+ inany_from_af(aa, AF_INET6, &sa->sa6.sin6_addr);
+ *port = ntohs(sa->sa6.sin6_port);
} else if (sa->sa_family == AF_INET) {
- struct sockaddr_in *sa4 = (struct sockaddr_in *)sa;
-
- inany_from_af(aa, AF_INET, &sa4->sin_addr);
- *port = ntohs(sa4->sin_port);
+ inany_from_af(aa, AF_INET, &sa->sa4.sin_addr);
+ *port = ntohs(sa->sa4.sin_port);
} else {
/* Not valid to call with other address families */
ASSERT(0);
diff --git a/tcp.c b/tcp.c
index bb914bff..a52a1f84 100644
--- a/tcp.c
+++ b/tcp.c
@@ -2685,7 +2685,7 @@ static void tcp_snat_inbound(const struct ctx *c, union inany_addr
*addr)
static void tcp_tap_conn_from_sock(struct ctx *c,
union tcp_listen_epoll_ref ref,
struct tcp_tap_conn *conn, int s,
- const struct sockaddr *sa,
+ const union sockaddr_inany *sa,
const struct timespec *now)
{
conn->f.type = FLOW_TCP;
@@ -2721,7 +2721,7 @@ static void tcp_tap_conn_from_sock(struct ctx *c,
void tcp_listen_handler(struct ctx *c, union epoll_ref ref,
const struct timespec *now)
{
- struct sockaddr_storage sa;
+ union sockaddr_inany sa;
socklen_t sl = sizeof(sa);
union flow *flow;
int s;
@@ -2729,16 +2729,15 @@ void tcp_listen_handler(struct ctx *c, union epoll_ref ref,
if (c->no_tcp || !(flow = flow_alloc()))
return;
- s = accept4(ref.fd, (struct sockaddr *)&sa, &sl, SOCK_NONBLOCK);
+ s = accept4(ref.fd, &sa.sa, &sl, SOCK_NONBLOCK);
if (s < 0)
goto cancel;
if (tcp_splice_conn_from_sock(c, ref.tcp_listen, &flow->tcp_splice,
- s, (struct sockaddr *)&sa))
+ s, &sa))
return;
- tcp_tap_conn_from_sock(c, ref.tcp_listen, &flow->tcp, s,
- (struct sockaddr *)&sa, now);
+ tcp_tap_conn_from_sock(c, ref.tcp_listen, &flow->tcp, s, &sa, now);
return;
cancel:
diff --git a/tcp_splice.c b/tcp_splice.c
index 3b438313..3a2c0781 100644
--- a/tcp_splice.c
+++ b/tcp_splice.c
@@ -382,7 +382,7 @@ static int tcp_splice_connect(const struct ctx *c, struct
tcp_splice_conn *conn,
bool tcp_splice_conn_from_sock(const struct ctx *c,
union tcp_listen_epoll_ref ref,
struct tcp_splice_conn *conn, int s0,
- const struct sockaddr *sa)
+ const union sockaddr_inany *sa)
{
in_port_t srcport, dstport = ref.port;
union inany_addr src;
diff --git a/tcp_splice.h b/tcp_splice.h
index d3600807..f6557cd4 100644
--- a/tcp_splice.h
+++ b/tcp_splice.h
@@ -7,13 +7,14 @@
#define TCP_SPLICE_H
struct tcp_splice_conn;
+union sockaddr_inany;
void tcp_splice_sock_handler(struct ctx *c, union epoll_ref ref,
uint32_t events);
bool tcp_splice_conn_from_sock(const struct ctx *c,
union tcp_listen_epoll_ref ref,
struct tcp_splice_conn *conn, int s0,
- const struct sockaddr *sa);
+ const union sockaddr_inany *sa);
void tcp_splice_init(struct ctx *c);
#endif /* TCP_SPLICE_H */
--
2.43.0