On Fri, Sep 13, 2024 at 08:10:24PM +0800, Philo Lu wrote:
Hi Tiago,
On 2024/9/13 17:39, Tiago Lam wrote:
This patch reuses the framework already in place for sk_lookup, allowing it now to send a reply from the server fd directly, instead of having to create a socket bound to the original destination address and reply from there. It does this by passing the source address and port from where to reply from in a IP_ORIGDSTADDR ancilliary message passed in sendmsg.
Signed-off-by: Tiago Lam tiagolam@cloudflare.com
tools/testing/selftests/bpf/prog_tests/sk_lookup.c | 70 +++++++++++++++------- 1 file changed, 48 insertions(+), 22 deletions(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/sk_lookup.c b/tools/testing/selftests/bpf/prog_tests/sk_lookup.c index ae87c00867ba..b99aff2e3976 100644 --- a/tools/testing/selftests/bpf/prog_tests/sk_lookup.c +++ b/tools/testing/selftests/bpf/prog_tests/sk_lookup.c @@ -75,6 +75,7 @@ struct test { struct inet_addr listen_at; enum server accept_on; bool reuseport_has_conns; /* Add a connected socket to reuseport group */
- bool dont_bind_reply; /* Don't bind, send direct from server fd. */ }; struct cb_opts {
@@ -363,7 +364,7 @@ static void v4_to_v6(struct sockaddr_storage *ss) memset(&v6->sin6_addr.s6_addr[0], 0, 10); } -static int udp_recv_send(int server_fd) +static int udp_recv_send(int server_fd, bool dont_bind_reply) { char cmsg_buf[CMSG_SPACE(sizeof(struct sockaddr_storage))]; struct sockaddr_storage _src_addr = { 0 }; @@ -415,26 +416,41 @@ static int udp_recv_send(int server_fd) v4_to_v6(dst_addr); }
- /* Reply from original destination address. */
- fd = start_server_addr(SOCK_DGRAM, dst_addr, sizeof(*dst_addr), NULL);
- if (!ASSERT_OK_FD(fd, "start_server_addr")) {
log_err("failed to create tx socket");return -1;- }
- if (dont_bind_reply) {
/* Reply directly from server fd, specifying the source address and/or* port in struct msghdr.*/n = sendmsg(server_fd, &msg, 0);if (CHECK(n <= 0, "sendmsg", "failed\n")) {log_err("failed to send echo reply");return -1;}- } else {
/* Reply from original destination address. */fd = socket(dst_addr->ss_family, SOCK_DGRAM, 0);if (CHECK(fd < 0, "socket", "failed\n")) {log_err("failed to create tx socket");return -1;}Just curious, why not use start_server_addr() here like before?
Thanks, you're right. Initially I rebased this on commit e3d332aaf898ed755b29c8cdf59be2cfba1cac4b (v6.6.31), which didn't have start_server_addr(), and used bind() instead. I must have messed up the rebased.
I've fixed this and included your other suggestion in the patch below and will fold it into the next revision.
diff --git a/tools/testing/selftests/bpf/prog_tests/sk_lookup.c b/tools/testing/selftests/bpf/prog_tests/sk_lookup.c index b99aff2e3976..0628a67681c5 100644 --- a/tools/testing/selftests/bpf/prog_tests/sk_lookup.c +++ b/tools/testing/selftests/bpf/prog_tests/sk_lookup.c @@ -374,7 +374,7 @@ static int udp_recv_send(int server_fd, bool dont_bind_reply) struct iovec iov = { 0 }; struct cmsghdr *cm; char buf[1]; - int ret, fd; + int fd; ssize_t n;
iov.iov_base = buf; @@ -427,19 +427,12 @@ static int udp_recv_send(int server_fd, bool dont_bind_reply) } } else { /* Reply from original destination address. */ - fd = socket(dst_addr->ss_family, SOCK_DGRAM, 0); - if (CHECK(fd < 0, "socket", "failed\n")) { + fd = start_server_addr(SOCK_DGRAM, dst_addr, sizeof(*dst_addr), NULL); + if (!ASSERT_OK_FD(fd, "start_server_addr")) { log_err("failed to create tx socket"); return -1; }
- ret = bind(fd, (struct sockaddr *)dst_addr, sizeof(*dst_addr)); - if (CHECK(ret, "bind", "failed\n")) { - log_err("failed to bind tx socket"); - close(fd); - return ret; - } - msg.msg_control = NULL; msg.msg_controllen = 0; n = sendmsg(fd, &msg, 0); @@ -451,6 +444,8 @@ static int udp_recv_send(int server_fd, bool dont_bind_reply)
close(fd); } + + return 0; }
static int tcp_echo_test(int client_fd, int server_fd)