[Qemu-devel] [PATCH/RFC 4/7] Allow saving screendump to a UNIX socket

["Marc-André Lureau" <marcandre.lureau@gmail.com>]

By using the 'unix:' prefix notation, similar to the migration uri, we
can now dump to a UNIX socket. IO is still sync
---
 hw/vga.c    |   64 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 qemu-file.h |    1 +
 2 files changed, 63 insertions(+), 2 deletions(-)

diff --git a/hw/vga.c b/hw/vga.c
index 24af4a1..bb5df70 100644
--- a/hw/vga.c
+++ b/hw/vga.c
@@ -30,6 +30,7 @@
 #include "pixel_ops.h"
 #include "qemu-timer.h"
 #include "xen.h"
+#include "qemu_socket.h"
 
 //#define DEBUG_VGA
 //#define DEBUG_VGA_MEM
@@ -37,6 +38,14 @@
 
 //#define DEBUG_BOCHS_VBE
 
+#ifdef DEBUG_VGA
+#define DPRINTF(fmt, ...) \
+    do { printf("vga: " fmt, ## __VA_ARGS__); } while (0)
+#else
+#define DPRINTF(fmt, ...) \
+    do { } while (0)
+#endif
+
 /*
  * Video Graphics Array (VGA)
  *
@@ -2362,7 +2371,58 @@ void vga_init_vbe(VGACommonState *s, MemoryRegion *system_memory)
 /********************************************************/
 /* vga screen dump */
 
-int ppm_save(const char *filename, struct DisplaySurface *ds)
+#if !defined(WIN32)
+static QEMUFile *qemu_fopen_unix(const char *path, const char *mode)
+{
+    struct sockaddr_un addr;
+    int ret, fd;
+
+    addr.sun_family = AF_UNIX;
+    snprintf(addr.sun_path, sizeof(addr.sun_path), "%s", path);
+
+    fd = qemu_socket(PF_UNIX, SOCK_STREAM, 0);
+    if (fd == -1) {
+        DPRINTF("Unable to open socket: %s\n", strerror(errno));
+        return NULL;
+    }
+
+    do {
+        ret = connect(fd, (struct sockaddr *)&addr, sizeof(addr));
+        if (ret == -1) {
+            ret = -errno;
+        }
+    } while (ret == -EINTR);
+
+    if (ret < 0) {
+        DPRINTF("connect failed: %s\n": strerror(errno));
+        return NULL;
+    }
+
+    return qemu_fopen_socket(fd, mode);
+}
+#endif
+
+QEMUFile *qemu_fopen_uri(const char *uri, const char *mode)
+{
+    QEMUFile *f = NULL;
+    const char *p;
+
+    g_return_val_if_fail(uri != NULL, NULL);
+    g_return_val_if_fail(mode != NULL, NULL);
+
+#if !defined(WIN32)
+    if (strstart(uri, "unix:", &p)) {
+        f = qemu_fopen_unix(p, mode);
+    }
+#endif
+    if (f == NULL) {
+        f = qemu_fopen(uri, mode);
+    }
+
+    return f;
+}
+
+int ppm_save(const char *uri, struct DisplaySurface *ds)
 {
     QEMUFile *f;
     uint8_t *d, *d1;
@@ -2372,7 +2432,7 @@ int ppm_save(const char *filename, struct DisplaySurface *ds)
     char *linebuf, *pbuf;
     gchar *header;
 
-    f = qemu_fopen(filename, "wb");
+    f = qemu_fopen_uri(uri, "wb");
     g_return_val_if_fail(f != NULL, -1);
 
     header = g_strdup_printf("P6\n%d %d\n%d\n", ds->width, ds->height, 255);
diff --git a/qemu-file.h b/qemu-file.h
index efd6b1c..0914d83 100644
--- a/qemu-file.h
+++ b/qemu-file.h
@@ -68,6 +68,7 @@ QEMUFile *qemu_fopen_ops(void *opaque, QEMUFilePutBufferFunc *put_buffer,
 QEMUFile *qemu_fopen(const char *filename, const char *mode);
 QEMUFile *qemu_fdopen(int fd, const char *mode);
 QEMUFile *qemu_fopen_socket(int fd, const char *mode);
+QEMUFile *qemu_fopen_uri(const char *uri, const char *mode);
 QEMUFile *qemu_popen(FILE *popen_file, const char *mode);
 QEMUFile *qemu_popen_cmd(const char *command, const char *mode);
 int qemu_stdio_fd(QEMUFile *f);
-- 
1.7.7.6