udp_splice_namebuf is now used only for spliced sending, and so it is only ever populated with the localhost address, either IPv4 or IPv6. So, replace the awkward initialization in udp_sock_handler_splice() with statically initialized versions for IPv4 and IPv6. We then just need to update the port number in udp_sock_handler_splice(). Signed-off-by: David Gibson <david(a)gibson.dropbear.id.au> --- udp.c | 40 ++++++++++++++++++---------------------- util.h | 7 +++++++ 2 files changed, 25 insertions(+), 22 deletions(-) diff --git a/udp.c b/udp.c index 6951c4c..f6c07a5 100644 --- a/udp.c +++ b/udp.c @@ -232,11 +232,18 @@ static struct mmsghdr udp4_l2_mh_tap [UDP_MAX_FRAMES]; static struct mmsghdr udp6_l2_mh_tap [UDP_MAX_FRAMES]; /* recvmmsg()/sendmmsg() data for "spliced" connections */ -static struct sockaddr_storage udp_splice_namebuf; - static struct iovec udp4_iov_splice [UDP_MAX_FRAMES]; static struct iovec udp6_iov_splice [UDP_MAX_FRAMES]; +static struct sockaddr_in udp4_localname = { + .sin_family = AF_INET, + .sin_addr = IN4ADDR_LOOPBACK_INIT, +}; +static struct sockaddr_in6 udp6_localname = { + .sin6_family = AF_INET6, + .sin6_addr = IN6ADDR_LOOPBACK_INIT, +}; + static struct mmsghdr udp4_mh_splice [UDP_MAX_FRAMES]; static struct mmsghdr udp6_mh_splice [UDP_MAX_FRAMES]; @@ -610,23 +617,10 @@ static void udp_sock_handler_splice(const struct ctx *c, union epoll_ref ref, if (n <= 0) return; - if (v6) { - *((struct sockaddr_in6 *)&udp_splice_namebuf) = - ((struct sockaddr_in6) { - .sin6_family = AF_INET6, - .sin6_addr = IN6ADDR_LOOPBACK_INIT, - .sin6_port = htons(dst), - .sin6_scope_id = 0, - }); - } else { - *((struct sockaddr_in *)&udp_splice_namebuf) = - ((struct sockaddr_in) { - .sin_family = AF_INET, - .sin_addr = { .s_addr = htonl(INADDR_LOOPBACK) }, - .sin_port = htons(dst), - .sin_zero = { 0 }, - }); - } + if (v6) + udp6_localname.sin6_port = htons(dst); + else + udp4_localname.sin_port = htons(dst); for (i = 0; i < n; i += m) { in_port_t src = sa_port(v6, mmh_recv[i].msg_hdr.msg_name); @@ -1256,9 +1250,11 @@ static void udp_splice_iov_init(void) struct msghdr *mh4 = &udp4_mh_splice[i].msg_hdr; struct msghdr *mh6 = &udp6_mh_splice[i].msg_hdr; - mh4->msg_name = mh6->msg_name = &udp_splice_namebuf; - mh4->msg_namelen = sizeof(udp_splice_namebuf); - mh6->msg_namelen = sizeof(udp_splice_namebuf); + mh4->msg_name = &udp4_localname; + mh4->msg_namelen = sizeof(udp4_localname); + + mh6->msg_name = &udp6_localname; + mh6->msg_namelen = sizeof(udp6_localname); udp4_iov_splice[i].iov_base = udp4_l2_buf[i].data; udp6_iov_splice[i].iov_base = udp6_l2_buf[i].data; diff --git a/util.h b/util.h index 02b55a9..3baec91 100644 --- a/util.h +++ b/util.h @@ -79,6 +79,13 @@ (IN_MULTICAST(ntohl((a)->s_addr))) #define IN4_ARE_ADDR_EQUAL(a, b) \ (((struct in_addr *)(a))->s_addr == ((struct in_addr *)b)->s_addr) +#if __BYTE_ORDER == __BIG_ENDIAN +#define IN4ADDR_LOOPBACK_INIT \ + { .s_addr = INADDR_LOOPBACK } +#else +#define IN4ADDR_LOOPBACK_INIT \ + { .s_addr = __bswap_constant_32(INADDR_LOOPBACK) } +#endif #define NS_FN_STACK_SIZE (RLIMIT_STACK_VAL * 1024 / 8) int do_clone(int (*fn)(void *), char *stack_area, size_t stack_size, int flags, -- 2.39.0