Paolo Bonzini <pbonz...@redhat.com> writes:
> Before:
>
> $ qemu-system-x86_64 -vnc foo.bar:12345
> getaddrinfo(foo.bar,18245): Name or service not known
> Failed to start VNC server on `foo.bar:12345'
>
> $ qemu-system-x86_64 -vnc localhost:12345,reverse=on
> inet_connect_opts: connect(ipv4,yakj.usersys.redhat.com,127.0.0.1,12345):
> Connection refused
> Failed to start VNC server on `localhost:12345,reverse=on'
>
> After:
>
> $ x86_64-softmmu/qemu-system-x86_64 -vnc foo.bar:12345
> Failed to start VNC server on `foo.bar:12345': address resolution failed
> for foo.bar:18245: Name or service not known
>
> $ x86_64-softmmu/qemu-system-x86_64 -vnc localhost:12345,reverse=on
> Failed to start VNC server on `localhost:12345,reverse=on': Failed to
> connect to socket: Connection refused
>
> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
> ---
> v1->v2: small cleanup for the if(reverse) case, do not use
> qerror_report_err.
>
> migration-exec.c | 18 ++++--------------
> console.h | 2 +-
> qmp.c | 6 ++---
> ui/vnc.c | 91
> +++++++++++++++++++++++++++++----------------------------------
> vl.c | 9 ++++---
> 4 file modificati, 51 inserzioni(+), 57 rimozioni(-)
>
> diff --git a/console.h b/console.h
> index f990684..6099d8d 100644
> --- a/console.h
> +++ b/console.h
> @@ -378,7 +378,7 @@ void cocoa_display_init(DisplayState *ds, int
> full_screen);
> /* vnc.c */
> void vnc_display_init(DisplayState *ds);
> void vnc_display_close(DisplayState *ds);
> -int vnc_display_open(DisplayState *ds, const char *display);
> +void vnc_display_open(DisplayState *ds, const char *display, Error **errp);
> void vnc_display_add_client(DisplayState *ds, int csock, int skipauth);
> int vnc_display_disable_login(DisplayState *ds);
> char *vnc_display_local_addr(DisplayState *ds);
> diff --git a/qmp.c b/qmp.c
> index 36c54c5..31bc3bf 100644
> --- a/qmp.c
> +++ b/qmp.c
> @@ -349,11 +349,9 @@ void qmp_change_vnc_password(const char *password, Error
> **errp)
> }
> }
>
> -static void qmp_change_vnc_listen(const char *target, Error **err)
> +static void qmp_change_vnc_listen(const char *target, Error **errp)
> {
> - if (vnc_display_open(NULL, target) < 0) {
> - error_set(err, QERR_VNC_SERVER_FAILED, target);
> - }
> + vnc_display_open(NULL, target, errp);
> }
>
> static void qmp_change_vnc(const char *target, bool has_arg, const char *arg,
> diff --git a/ui/vnc.c b/ui/vnc.c
> index 235596e..b8e46ca 100644
> --- a/ui/vnc.c
> +++ b/ui/vnc.c
> @@ -2844,7 +2844,7 @@ char *vnc_display_local_addr(DisplayState *ds)
> return vnc_socket_local_addr("%s:%s", vs->lsock);
> }
>
> -int vnc_display_open(DisplayState *ds, const char *display)
> +void vnc_display_open(DisplayState *ds, const char *display, Error **errp)
> {
> VncDisplay *vs = ds ? (VncDisplay *)ds->opaque : vnc_display;
> const char *options;
> @@ -2863,13 +2863,12 @@ int vnc_display_open(DisplayState *ds, const char
> *display)
> int lock_key_sync = 1;
>
> if (!vnc_display)
> - return -1;
> + goto fail;
Now executes
g_free(vs->display);
vs->display = NULL;
The latter looks innocent enough, but why is the former safe?
> vnc_display_close(ds);
> if (strcmp(display, "none") == 0)
> - return 0;
> + return;
>
> - if (!(vs->display = strdup(display)))
> - return -1;
> + vs->display = g_strdup(display);
> vs->share_policy = VNC_SHARE_POLICY_ALLOW_EXCLUSIVE;
>
> options = display;
> @@ -2877,13 +2876,11 @@ int vnc_display_open(DisplayState *ds, const char
> *display)
> options++;
> if (strncmp(options, "password", 8) == 0) {
> if (fips_get_state()) {
> - fprintf(stderr,
> - "VNC password auth disabled due to FIPS mode, "
> - "consider using the VeNCrypt or SASL authentication "
> - "methods as an alternative\n");
> - g_free(vs->display);
> - vs->display = NULL;
> - return -1;
> + error_setg(errp,
> + "VNC password auth disabled due to FIPS mode, "
> + "consider using the VeNCrypt or SASL
> authentication "
> + "methods as an alternative\n");
Message for error_setg() should not end with '\n'.
> + goto fail;
> }
> password = 1; /* Require password auth */
> } else if (strncmp(options, "reverse", 7) == 0) {
> @@ -2913,18 +2910,14 @@ int vnc_display_open(DisplayState *ds, const char
> *display)
>
> VNC_DEBUG("Trying certificate path '%s'\n", path);
> if (vnc_tls_set_x509_creds_dir(vs, path) < 0) {
> - fprintf(stderr, "Failed to find x509 certificates/keys
> in %s\n", path);
> + error_setg(errp, "Failed to find x509 certificates/keys
> in %s\n", path);
Likewise.
> g_free(path);
> - g_free(vs->display);
> - vs->display = NULL;
> - return -1;
> + goto fail;
> }
> g_free(path);
> } else {
> - fprintf(stderr, "No certificate path provided\n");
> - g_free(vs->display);
> - vs->display = NULL;
> - return -1;
> + error_setg(errp, "No certificate path provided\n");
Likewise.
> + goto fail;
> }
> #endif
> #if defined(CONFIG_VNC_TLS) || defined(CONFIG_VNC_SASL)
> @@ -2943,10 +2936,8 @@ int vnc_display_open(DisplayState *ds, const char
> *display)
> } else if (strncmp(options+6, "force-shared", 12) == 0) {
> vs->share_policy = VNC_SHARE_POLICY_FORCE_SHARED;
> } else {
> - fprintf(stderr, "unknown vnc share= option\n");
> - g_free(vs->display);
> - vs->display = NULL;
> - return -1;
> + error_setg(errp, "unknown vnc share= option\n");
Likewise.
> + goto fail;
> }
> }
> }
> @@ -3047,52 +3038,54 @@ int vnc_display_open(DisplayState *ds, const char
> *display)
>
> #ifdef CONFIG_VNC_SASL
> if ((saslErr = sasl_server_init(NULL, "qemu")) != SASL_OK) {
> - fprintf(stderr, "Failed to initialize SASL auth %s",
> - sasl_errstring(saslErr, NULL, NULL));
> - g_free(vs->display);
> - vs->display = NULL;
> - return -1;
> + error_setg(errp, "Failed to initialize SASL auth %s",
> + sasl_errstring(saslErr, NULL, NULL));
> + goto fail;
> }
> #endif
> vs->lock_key_sync = lock_key_sync;
>
> if (reverse) {
> /* connect to viewer */
> - if (strncmp(display, "unix:", 5) == 0)
> - vs->lsock = unix_connect(display+5, NULL);
> - else
> - vs->lsock = inet_connect(display, NULL);
> - if (-1 == vs->lsock) {
> - g_free(vs->display);
> - vs->display = NULL;
> - return -1;
> + int csock;
> + vs->lsock = -1;
> + if (strncmp(display, "unix:", 5) == 0) {
> + csock = unix_connect(display+5, errp);
> } else {
> - int csock = vs->lsock;
> - vs->lsock = -1;
> - vnc_connect(vs, csock, 0);
> + csock = inet_connect(display, errp);
> }
The csock / vs->lsock change confused me. I think it's correct, but I
wish it was a separate cleanup commit.
Same for the goto fail cleanup, by the way.
> - return 0;
> -
> + if (-1 == csock) {
csock < 0, please.
> + goto fail;
> + }
> + vnc_connect(vs, csock, 0);
> } else {
> /* listen for connects */
> char *dpy;
> dpy = g_malloc(256);
> if (strncmp(display, "unix:", 5) == 0) {
> pstrcpy(dpy, 256, "unix:");
> - vs->lsock = unix_listen(display+5, dpy+5, 256-5, NULL);
> + vs->lsock = unix_listen(display+5, dpy+5, 256-5, errp);
> } else {
> vs->lsock = inet_listen(display, dpy, 256,
> - SOCK_STREAM, 5900, NULL);
> + SOCK_STREAM, 5900, errp);
> }
> if (-1 == vs->lsock) {
> g_free(dpy);
> - return -1;
> - } else {
> - g_free(vs->display);
> - vs->display = dpy;
> + goto fail;
Now executes
g_free(vs->display);
vs->display = NULL;
Silent bug fix?
If yes, it should really be a separate commit!
> }
> + g_free(vs->display);
> + vs->display = dpy;
> + qemu_set_fd_handler2(vs->lsock, NULL, vnc_listen_read, NULL, vs);
> + }
> + return;
> +
> +fail:
> + if (!error_is_set(errp)) {
> + error_set(errp, QERR_VNC_SERVER_FAILED, display);
How can we get here with no error set?
1. !vnc_display (first goto fail).
2. unit_connect() or inet_listen() return failure, but don't set error.
3. unix_listen() or inet_listen() return failure, but don't set error.
Can 2. or 3. happen?
If yes, these functions suck. If no, let's fix up 1. to set a suitable
error, and drop the uninformative generic error here.
> }
> - return qemu_set_fd_handler2(vs->lsock, NULL, vnc_listen_read, NULL, vs);
> + g_free(vs->display);
> + vs->display = NULL;
> + return;
> }
>
> void vnc_display_add_client(DisplayState *ds, int csock, int skipauth)
> diff --git a/vl.c b/vl.c
> index 2a072e8..67a624f 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -3706,10 +3706,13 @@ int main(int argc, char **argv, char **envp)
> #ifdef CONFIG_VNC
> /* init remote displays */
> if (vnc_display) {
> + Error *local_err = NULL;
> vnc_display_init(ds);
> - if (vnc_display_open(ds, vnc_display) < 0) {
> - fprintf(stderr, "Failed to start VNC server on `%s'\n",
> - vnc_display);
> + vnc_display_open(ds, vnc_display, &local_err);
> + if (local_err != NULL) {
> + fprintf(stderr, "Failed to start VNC server on `%s': %s\n",
> + vnc_display, error_get_pretty(local_err));
> + error_free(local_err);
> exit(1);
> }
