Instead of just checking whether it is possible to bind() on a socket, also
check that we can successfully connect() to the socket we bound to. This
more closely replicates the level of functionality that tests will actually
use.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
---
 tests/socket-helpers.c | 67 +++++++++++++++++++++++++++++++++++++++++++-------
 tests/socket-helpers.h |  4 +--
 2 files changed, 60 insertions(+), 11 deletions(-)

diff --git a/tests/socket-helpers.c b/tests/socket-helpers.c
index 13b6bb38eb..161aa5da09 100644
--- a/tests/socket-helpers.c
+++ b/tests/socket-helpers.c
@@ -30,10 +30,15 @@
 # define EAI_ADDRFAMILY 0
 #endif
 
-int socket_can_bind(const char *hostname)
+int socket_can_bind_connect(const char *hostname)
 {
-    int fd = -1;
+    int lfd = -1, cfd = -1, afd = -1;
     struct addrinfo ai, *res = NULL;
+    struct sockaddr_storage ss;
+    socklen_t sslen = sizeof(ss);
+    int soerr;
+    socklen_t soerrlen = sizeof(soerr);
+    bool check_soerr = false;
     int rc;
     int ret = -1;
 
@@ -54,24 +59,68 @@ int socket_can_bind(const char *hostname)
         goto cleanup;
     }
 
-    fd = qemu_socket(res->ai_family, res->ai_socktype, res->ai_protocol);
-    if (fd < 0) {
+    lfd = qemu_socket(res->ai_family, res->ai_socktype, res->ai_protocol);
+    if (lfd < 0) {
         goto cleanup;
     }
 
-    if (bind(fd, res->ai_addr, res->ai_addrlen) < 0) {
+    cfd = qemu_socket(res->ai_family, res->ai_socktype, res->ai_protocol);
+    if (cfd < 0) {
+        goto cleanup;
+    }
+
+    if (bind(lfd, res->ai_addr, res->ai_addrlen) < 0) {
         if (errno == EADDRNOTAVAIL) {
             goto done;
         }
         goto cleanup;
     }
 
+    if (listen(lfd, 1) < 0) {
+        goto cleanup;
+    }
+
+    if (getsockname(lfd, (struct sockaddr *)&ss, &sslen) < 0) {
+        goto cleanup;
+    }
+
+    qemu_set_nonblock(cfd);
+    if (connect(cfd, (struct sockaddr *)&ss, sslen) < 0) {
+        if (errno == EINPROGRESS) {
+            check_soerr = true;
+        } else {
+            goto cleanup;
+        }
+    }
+
+    sslen = sizeof(ss);
+    afd = accept(lfd,  (struct sockaddr *)&ss, &sslen);
+    if (afd < 0) {
+        goto cleanup;
+    }
+
+    if (check_soerr) {
+        if (qemu_getsockopt(cfd, SOL_SOCKET, SO_ERROR, &soerr, &soerrlen) < 0) {
+            goto cleanup;
+        }
+        if (soerr) {
+            errno = soerr;
+            goto cleanup;
+        }
+    }
+
  done:
     ret = 0;
 
  cleanup:
-    if (fd != -1) {
-        close(fd);
+    if (afd != -1) {
+        close(afd);
+    }
+    if (cfd != -1) {
+        close(cfd);
+    }
+    if (lfd != -1) {
+        close(lfd);
     }
     if (res) {
         freeaddrinfo(res);
@@ -84,7 +133,7 @@ int socket_check_protocol_support(bool *has_ipv4, bool *has_ipv6)
 {
     *has_ipv4 = *has_ipv6 = false;
 
-    if (socket_can_bind("127.0.0.1") < 0) {
+    if (socket_can_bind_connect("127.0.0.1") < 0) {
         if (errno != EADDRNOTAVAIL) {
             return -1;
         }
@@ -92,7 +141,7 @@ int socket_check_protocol_support(bool *has_ipv4, bool *has_ipv6)
         *has_ipv4 = true;
     }
 
-    if (socket_can_bind("::1") < 0) {
+    if (socket_can_bind_connect("::1") < 0) {
         if (errno != EADDRNOTAVAIL) {
             return -1;
         }
diff --git a/tests/socket-helpers.h b/tests/socket-helpers.h
index efa96eddc2..1c07d6d656 100644
--- a/tests/socket-helpers.h
+++ b/tests/socket-helpers.h
@@ -21,13 +21,13 @@
 /*
  * @hostname: a DNS name or numeric IP address
  *
- * Check whether it is possible to bind to ports
+ * Check whether it is possible to bind & connect to ports
  * on the DNS name or IP address @hostname. If an IP address
  * is used, it must not be a wildcard address.
  *
  * Returns 0 on success, -1 on error with errno set
  */
-int socket_can_bind(const char *hostname);
+int socket_can_bind_connect(const char *hostname);
 
 /*
  * @has_ipv4: set to true on return if IPv4 is available
-- 
2.14.3

On Fri, Dec 22, 2017 at 2:45 PM, Daniel P. Berrange <berrange@redhat.com> wrote:
> Instead of just checking whether it is possible to bind() on a socket, also
> check that we can successfully connect() to the socket we bound to. This
> more closely replicates the level of functionality that tests will actually
> use.
>
> Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>


> ---
>  tests/socket-helpers.c | 67 +++++++++++++++++++++++++++++++++++++++++++-------
>  tests/socket-helpers.h |  4 +--
>  2 files changed, 60 insertions(+), 11 deletions(-)
>
> diff --git a/tests/socket-helpers.c b/tests/socket-helpers.c
> index 13b6bb38eb..161aa5da09 100644
> --- a/tests/socket-helpers.c
> +++ b/tests/socket-helpers.c
> @@ -30,10 +30,15 @@
>  # define EAI_ADDRFAMILY 0
>  #endif
>
> -int socket_can_bind(const char *hostname)
> +int socket_can_bind_connect(const char *hostname)
>  {
> -    int fd = -1;
> +    int lfd = -1, cfd = -1, afd = -1;
>      struct addrinfo ai, *res = NULL;
> +    struct sockaddr_storage ss;
> +    socklen_t sslen = sizeof(ss);
> +    int soerr;
> +    socklen_t soerrlen = sizeof(soerr);
> +    bool check_soerr = false;
>      int rc;
>      int ret = -1;
>
> @@ -54,24 +59,68 @@ int socket_can_bind(const char *hostname)
>          goto cleanup;
>      }
>
> -    fd = qemu_socket(res->ai_family, res->ai_socktype, res->ai_protocol);
> -    if (fd < 0) {
> +    lfd = qemu_socket(res->ai_family, res->ai_socktype, res->ai_protocol);
> +    if (lfd < 0) {
>          goto cleanup;
>      }
>
> -    if (bind(fd, res->ai_addr, res->ai_addrlen) < 0) {
> +    cfd = qemu_socket(res->ai_family, res->ai_socktype, res->ai_protocol);
> +    if (cfd < 0) {
> +        goto cleanup;
> +    }
> +
> +    if (bind(lfd, res->ai_addr, res->ai_addrlen) < 0) {
>          if (errno == EADDRNOTAVAIL) {
>              goto done;
>          }
>          goto cleanup;
>      }
>
> +    if (listen(lfd, 1) < 0) {
> +        goto cleanup;
> +    }
> +
> +    if (getsockname(lfd, (struct sockaddr *)&ss, &sslen) < 0) {
> +        goto cleanup;
> +    }
> +
> +    qemu_set_nonblock(cfd);
> +    if (connect(cfd, (struct sockaddr *)&ss, sslen) < 0) {
> +        if (errno == EINPROGRESS) {
> +            check_soerr = true;
> +        } else {
> +            goto cleanup;
> +        }
> +    }
> +
> +    sslen = sizeof(ss);
> +    afd = accept(lfd,  (struct sockaddr *)&ss, &sslen);
> +    if (afd < 0) {
> +        goto cleanup;
> +    }
> +
> +    if (check_soerr) {
> +        if (qemu_getsockopt(cfd, SOL_SOCKET, SO_ERROR, &soerr, &soerrlen) < 0) {
> +            goto cleanup;
> +        }
> +        if (soerr) {
> +            errno = soerr;
> +            goto cleanup;
> +        }
> +    }
> +
>   done:
>      ret = 0;
>
>   cleanup:
> -    if (fd != -1) {
> -        close(fd);
> +    if (afd != -1) {
> +        close(afd);
> +    }
> +    if (cfd != -1) {
> +        close(cfd);
> +    }
> +    if (lfd != -1) {
> +        close(lfd);
>      }
>      if (res) {
>          freeaddrinfo(res);
> @@ -84,7 +133,7 @@ int socket_check_protocol_support(bool *has_ipv4, bool *has_ipv6)
>  {
>      *has_ipv4 = *has_ipv6 = false;
>
> -    if (socket_can_bind("127.0.0.1") < 0) {
> +    if (socket_can_bind_connect("127.0.0.1") < 0) {
>          if (errno != EADDRNOTAVAIL) {
>              return -1;
>          }
> @@ -92,7 +141,7 @@ int socket_check_protocol_support(bool *has_ipv4, bool *has_ipv6)
>          *has_ipv4 = true;
>      }
>
> -    if (socket_can_bind("::1") < 0) {
> +    if (socket_can_bind_connect("::1") < 0) {
>          if (errno != EADDRNOTAVAIL) {
>              return -1;
>          }
> diff --git a/tests/socket-helpers.h b/tests/socket-helpers.h
> index efa96eddc2..1c07d6d656 100644
> --- a/tests/socket-helpers.h
> +++ b/tests/socket-helpers.h
> @@ -21,13 +21,13 @@
>  /*
>   * @hostname: a DNS name or numeric IP address
>   *
> - * Check whether it is possible to bind to ports
> + * Check whether it is possible to bind & connect to ports
>   * on the DNS name or IP address @hostname. If an IP address
>   * is used, it must not be a wildcard address.
>   *
>   * Returns 0 on success, -1 on error with errno set
>   */
> -int socket_can_bind(const char *hostname);
> +int socket_can_bind_connect(const char *hostname);
>
>  /*
>   * @has_ipv4: set to true on return if IPv4 is available
> --
> 2.14.3
>
>



-- 
Marc-André Lureau