inany: Introduce union sockaddr_inany

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@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This commit is contained in:
David Gibson 2024-02-28 22:25:04 +11:00 committed by Stefano Brivio
parent 0cf6b2d89d
commit f6e6e8ad40
5 changed files with 35 additions and 32 deletions

18
icmp.c
View File

@ -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;

33
inany.h
View File

@ -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
@ -41,6 +43,19 @@ extern const union inany_addr inany_any4;
#define in4addr_loopback (inany_loopback4.v4mapped.a4)
#define in4addr_any (inany_any4.v4mapped.a4)
/** 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
*
@ -137,23 +152,17 @@ 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);

11
tcp.c
View File

@ -2689,7 +2689,7 @@ 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;
@ -2725,7 +2725,7 @@ 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;
@ -2733,17 +2733,16 @@ 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 (c->mode == MODE_PASTA &&
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:

View File

@ -447,7 +447,7 @@ static int tcp_splice_new(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 s,
const struct sockaddr *sa)
const union sockaddr_inany *sa)
{
union inany_addr aany;
in_port_t port;

View File

@ -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 s,
const struct sockaddr *sa);
const union sockaddr_inany *sa);
void tcp_splice_init(struct ctx *c);
#endif /* TCP_SPLICE_H */