[PATCH net-next] selftests: net/psock_lib: Handle EINTR and EAGAIN

[Leo Stone]

Make pair_udp_send_char handle EAGAIN, EINTR, and partial reads or
writes.

Signed-off-by: Leo Stone <leocst...@gmail.com>
---
 tools/testing/selftests/net/psock_lib.h | 39 +++++++++++++++++++------
 1 file changed, 30 insertions(+), 9 deletions(-)

diff --git a/tools/testing/selftests/net/psock_lib.h 
b/tools/testing/selftests/net/psock_lib.h
index 6e4fef560873..e28bff95c8e2 100644
--- a/tools/testing/selftests/net/psock_lib.h
+++ b/tools/testing/selftests/net/psock_lib.h
@@ -13,6 +13,7 @@
 #include <string.h>
 #include <arpa/inet.h>
 #include <unistd.h>
+#include <stdbool.h>
 
 #include "kselftest.h"
 
@@ -110,21 +111,41 @@ static __maybe_unused void pair_udp_open(int fds[], 
uint16_t port)
        }
 }
 
+static void read_write_checked(int fd, char *buf, size_t sz, bool is_write)
+{
+       int bytes_processed = 0;
+       int ret;
+
+       do {
+               if (is_write)
+                       ret = write(fd, buf + bytes_processed,
+                                   sz - bytes_processed);
+               else
+                       ret = read(fd, buf + bytes_processed,
+                                  sz - bytes_processed);
+               if (ret == -1) {
+                       if (errno == EAGAIN || errno == EINTR) {
+                               continue;
+                       } else {
+                               fprintf(stderr, "ERROR: %s failed, bytes 
left=%lu\n",
+                                       is_write ? "send" : "recv",
+                                       sz - bytes_processed);
+                               exit(1);
+                       }
+               }
+               bytes_processed += ret;
+       } while (bytes_processed < sz);
+}
+
 static __maybe_unused void pair_udp_send_char(int fds[], int num, char payload)
 {
        char buf[DATA_LEN], rbuf[DATA_LEN];
 
        memset(buf, payload, sizeof(buf));
        while (num--) {
-               /* Should really handle EINTR and EAGAIN */
-               if (write(fds[0], buf, sizeof(buf)) != sizeof(buf)) {
-                       fprintf(stderr, "ERROR: send failed left=%d\n", num);
-                       exit(1);
-               }
-               if (read(fds[1], rbuf, sizeof(rbuf)) != sizeof(rbuf)) {
-                       fprintf(stderr, "ERROR: recv failed left=%d\n", num);
-                       exit(1);
-               }
+               read_write_checked(fds[0], buf, sizeof(buf), true);
+               read_write_checked(fds[1], rbuf, sizeof(rbuf), false);
+
                if (memcmp(buf, rbuf, sizeof(buf))) {
                        fprintf(stderr, "ERROR: data failed left=%d\n", num);
                        exit(1);
-- 
2.39.5