[Qemu-devel] [RFC PATCH 1/2] vnc: hoist allocation of VncBasicInfo to callers

[Eric Blake <eblake@redhat.com>]

A future qapi patch will rework generated structs with a base
class to be unboxed.  In preparation for that, change the code
that allocates then populates an info struct to instead merely
populate the fields of an info field passed in as a parameter.
Add rudimentary Error handling for cases where the old code
returned NULL; but as before, callers merely ignore errors for
now.

Signed-off-by: Eric Blake <eblake@redhat.com>
---
 ui/vnc.c | 52 ++++++++++++++++++++++++++++------------------------
 1 file changed, 28 insertions(+), 24 deletions(-)

diff --git a/ui/vnc.c b/ui/vnc.c
index 1483958..7e2a017 100644
--- a/ui/vnc.c
+++ b/ui/vnc.c
@@ -153,10 +153,11 @@ char *vnc_socket_remote_addr(const char *format, int fd) {
     return addr_to_string(format, &sa, salen);
 }

-static VncBasicInfo *vnc_basic_info_get(struct sockaddr_storage *sa,
-                                        socklen_t salen)
+static void vnc_basic_info_get(struct sockaddr_storage *sa,
+                               socklen_t salen,
+                               VncBasicInfo *info,
+                               Error **errp)
 {
-    VncBasicInfo *info;
     char host[NI_MAXHOST];
     char serv[NI_MAXSERV];
     int err;
@@ -165,42 +166,44 @@ static VncBasicInfo *vnc_basic_info_get(struct sockaddr_storage *sa,
                            host, sizeof(host),
                            serv, sizeof(serv),
                            NI_NUMERICHOST | NI_NUMERICSERV)) != 0) {
-        VNC_DEBUG("Cannot resolve address %d: %s\n",
-                  err, gai_strerror(err));
-        return NULL;
+        error_setg(errp, "Cannot resolve address %d: %s",
+                   err, gai_strerror(err));
+        return;
     }

-    info = g_malloc0(sizeof(VncBasicInfo));
     info->host = g_strdup(host);
     info->service = g_strdup(serv);
     info->family = inet_netfamily(sa->ss_family);
-    return info;
 }

-static VncBasicInfo *vnc_basic_info_get_from_server_addr(int fd)
+static void vnc_basic_info_get_from_server_addr(int fd, VncBasicInfo *info,
+                                                Error **errp)
 {
     struct sockaddr_storage sa;
     socklen_t salen;

     salen = sizeof(sa);
     if (getsockname(fd, (struct sockaddr*)&sa, &salen) < 0) {
-        return NULL;
+        error_setg_errno(errp, errno, "getsockname failed");
+        return;
     }

-    return vnc_basic_info_get(&sa, salen);
+    vnc_basic_info_get(&sa, salen, info, errp);
 }

-static VncBasicInfo *vnc_basic_info_get_from_remote_addr(int fd)
+static void vnc_basic_info_get_from_remote_addr(int fd, VncBasicInfo *info,
+                                                Error **errp)
 {
     struct sockaddr_storage sa;
     socklen_t salen;

     salen = sizeof(sa);
     if (getpeername(fd, (struct sockaddr*)&sa, &salen) < 0) {
-        return NULL;
+        error_setg_errno(errp, errno, "getpeername failed");
+        return;
     }

-    return vnc_basic_info_get(&sa, salen);
+    vnc_basic_info_get(&sa, salen, info, errp);
 }

 static const char *vnc_auth_name(VncDisplay *vd) {
@@ -257,13 +260,10 @@ static const char *vnc_auth_name(VncDisplay *vd) {
 static VncServerInfo *vnc_server_info_get(VncDisplay *vd)
 {
     VncServerInfo *info;
-    VncBasicInfo *bi = vnc_basic_info_get_from_server_addr(vd->lsock);
-    if (!bi) {
-        return NULL;
-    }

     info = g_malloc(sizeof(*info));
-    info->base = bi;
+    info->base = g_malloc(sizeof(*info->base));
+    vnc_basic_info_get_from_server_addr(vd->lsock, info->base, NULL);
     info->has_auth = true;
     info->auth = g_strdup(vnc_auth_name(vd));
     return info;
@@ -293,11 +293,15 @@ static void vnc_client_cache_auth(VncState *client)

 static void vnc_client_cache_addr(VncState *client)
 {
-    VncBasicInfo *bi = vnc_basic_info_get_from_remote_addr(client->csock);
-
-    if (bi) {
-        client->info = g_malloc0(sizeof(*client->info));
-        client->info->base = bi;
+    Error *err = NULL;
+    client->info = g_malloc0(sizeof(*client->info));
+    client->info->base = g_malloc0(sizeof(*client->info->base));
+    vnc_basic_info_get_from_remote_addr(client->csock, client->info->base,
+                                        &err);
+    if (err) {
+        qapi_free_VncClientInfo(client->info);
+        client->info = NULL;
+        error_free(err);
     }
 }

-- 
2.4.3