selftests/net: add zerocopy support for PF_RDS test case

Send a cookie with sendmsg() on PF_RDS sockets, and process the
returned batched cookies in do_recv_completion()

Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 64 insertions, 4 deletions

diff --git a/tools/testing/selftests/net/msg_zerocopy.c b/tools/testing/selftests/net/msg_zerocopy.c
index 7a5b35362f84..5cc2a53bb71c 100644
--- a/tools/testing/selftests/net/msg_zerocopy.c
+++ b/tools/testing/selftests/net/msg_zerocopy.c
@@ -168,17 +168,39 @@ static int do_accept(int fd)
         return fd;
 }
 
-static bool do_sendmsg(int fd, struct msghdr *msg, bool do_zerocopy)
+static void add_zcopy_cookie(struct msghdr *msg, uint32_t cookie)
+{
+        struct cmsghdr *cm;
+
+        if (!msg->msg_control)
+                error(1, errno, "NULL cookie");
+        cm = (void *)msg->msg_control;
+        cm->cmsg_len = CMSG_LEN(sizeof(cookie));
+        cm->cmsg_level = SOL_RDS;
+        cm->cmsg_type = RDS_CMSG_ZCOPY_COOKIE;
+        memcpy(CMSG_DATA(cm), &cookie, sizeof(cookie));
+}
+
+static bool do_sendmsg(int fd, struct msghdr *msg, bool do_zerocopy, int domain)
 {
         int ret, len, i, flags;
+        static uint32_t cookie;
+        char ckbuf[CMSG_SPACE(sizeof(cookie))];
 
         len = 0;
         for (i = 0; i < msg->msg_iovlen; i++)
                 len += msg->msg_iov[i].iov_len;
 
         flags = MSG_DONTWAIT;
-        if (do_zerocopy)
+        if (do_zerocopy) {
                 flags |= MSG_ZEROCOPY;
+                if (domain == PF_RDS) {
+                        memset(&msg->msg_control, 0, sizeof(msg->msg_control));
+                        msg->msg_controllen = CMSG_SPACE(sizeof(cookie));
+                        msg->msg_control = (struct cmsghdr *)ckbuf;
+                        add_zcopy_cookie(msg, ++cookie);
+                }
+        }
 
         ret = sendmsg(fd, msg, flags);
         if (ret == -1 && errno == EAGAIN)
@@ -194,6 +216,10 @@ static bool do_sendmsg(int fd, struct msghdr *msg, bool do_zerocopy)
                 if (do_zerocopy && ret)
                         expected_completions++;
         }
+        if (do_zerocopy && domain == PF_RDS) {
+                msg->msg_control = NULL;
+                msg->msg_controllen = 0;
+        }
 
         return true;
 }
@@ -220,7 +246,9 @@ static void do_sendmsg_corked(int fd, struct msghdr *msg)
                 msg->msg_iov[0].iov_len = payload_len + extra_len;
                 extra_len = 0;
 
-                do_sendmsg(fd, msg, do_zerocopy);
+                do_sendmsg(fd, msg, do_zerocopy,
+                           (cfg_dst_addr.ss_family == AF_INET ?
+                            PF_INET : PF_INET6));
         }
 
         do_setsockopt(fd, IPPROTO_UDP, UDP_CORK, 0);
@@ -316,6 +344,26 @@ static int do_setup_tx(int domain, int type, int protocol)
         return fd;
 }
 
+static int do_process_zerocopy_cookies(struct sock_extended_err *serr,
+                                       uint32_t *ckbuf, size_t nbytes)
+{
+        int ncookies, i;
+
+        if (serr->ee_errno != 0)
+                error(1, 0, "serr: wrong error code: %u", serr->ee_errno);
+        ncookies = serr->ee_data;
+        if (ncookies > SO_EE_ORIGIN_MAX_ZCOOKIES)
+                error(1, 0, "Returned %d cookies, max expected %d\n",
+                      ncookies, SO_EE_ORIGIN_MAX_ZCOOKIES);
+        if (nbytes != ncookies * sizeof(uint32_t))
+                error(1, 0, "Expected %d cookies, got %ld\n",
+                      ncookies, nbytes/sizeof(uint32_t));
+        for (i = 0; i < ncookies; i++)
+                if (cfg_verbose >= 2)
+                        fprintf(stderr, "%d\n", ckbuf[i]);
+        return ncookies;
+}
+
 static bool do_recv_completion(int fd)
 {
         struct sock_extended_err *serr;
@@ -324,10 +372,17 @@ static bool do_recv_completion(int fd)
         uint32_t hi, lo, range;
         int ret, zerocopy;
         char control[100];
+        uint32_t ckbuf[SO_EE_ORIGIN_MAX_ZCOOKIES];
+        struct iovec iov;
 
         msg.msg_control = control;
         msg.msg_controllen = sizeof(control);
 
+        iov.iov_base = ckbuf;
+        iov.iov_len = (SO_EE_ORIGIN_MAX_ZCOOKIES * sizeof(ckbuf[0]));
+        msg.msg_iov = &iov;
+        msg.msg_iovlen = 1;
+
         ret = recvmsg(fd, &msg, MSG_ERRQUEUE);
         if (ret == -1 && errno == EAGAIN)
                 return false;
@@ -346,6 +401,11 @@ static bool do_recv_completion(int fd)
                       cm->cmsg_level, cm->cmsg_type);
 
         serr = (void *) CMSG_DATA(cm);
+
+        if (serr->ee_origin == SO_EE_ORIGIN_ZCOOKIE) {
+                completions += do_process_zerocopy_cookies(serr, ckbuf, ret);
+                return true;
+        }
         if (serr->ee_origin != SO_EE_ORIGIN_ZEROCOPY)
                 error(1, 0, "serr: wrong origin: %u", serr->ee_origin);
         if (serr->ee_errno != 0)
@@ -470,7 +530,7 @@ static void do_tx(int domain, int type, int protocol)
                 if (cfg_cork)
                         do_sendmsg_corked(fd, &msg);
                 else
-                        do_sendmsg(fd, &msg, cfg_zerocopy);
+                        do_sendmsg(fd, &msg, cfg_zerocopy, domain);
 
                 while (!do_poll(fd, POLLOUT)) {
                         if (cfg_zerocopy)