Commit e1a8c9b6 authored by Dr. David Alan Gilbert's avatar Dr. David Alan Gilbert Committed by Amit Shah
Browse files

socket shutdown 



Add QEMUFile interface to allow a socket to be 'shut down' - i.e. any
reads/writes will fail (and any blocking read/write will be woken).

Signed-off-by: default avatarDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: default avatarAmit Shah <amit.shah@redhat.com>
Signed-off-by: default avatarAmit Shah <amit.shah@redhat.com>
parent 8580b064

include/migration/qemu-file.h

+10 −0
Original line number Diff line number Diff line
@@ -84,6 +84,14 @@ typedef size_t (QEMURamSaveFunc)(QEMUFile *f, void *opaque, 
                               size_t size,

                               int *bytes_sent);



/*

 * Stop any read or write (depending on flags) on the underlying

 * transport on the QEMUFile.

 * Existing blocking reads/writes must be woken

 * Returns 0 on success, -err on error

 */

typedef int (QEMUFileShutdownFunc)(void *opaque, bool rd, bool wr);



typedef struct QEMUFileOps {

    QEMUFilePutBufferFunc *put_buffer;

    QEMUFileGetBufferFunc *get_buffer;
@@ -94,6 +102,7 @@ typedef struct QEMUFileOps { 
    QEMURamHookFunc *after_ram_iterate;

    QEMURamHookFunc *hook_ram_load;

    QEMURamSaveFunc *save_page;

    QEMUFileShutdownFunc *shut_down;

} QEMUFileOps;



struct QEMUSizedBuffer {
@@ -177,6 +186,7 @@ void qemu_file_set_rate_limit(QEMUFile *f, int64_t new_rate); 
int64_t qemu_file_get_rate_limit(QEMUFile *f);

int qemu_file_get_error(QEMUFile *f);

void qemu_file_set_error(QEMUFile *f, int ret);

int qemu_file_shutdown(QEMUFile *f);

void qemu_fflush(QEMUFile *f);



static inline void qemu_put_be64s(QEMUFile *f, const uint64_t *pv)

include/qemu/sockets.h

+7 −0
Original line number Diff line number Diff line
@@ -44,6 +44,13 @@ int socket_set_fast_reuse(int fd); 
int send_all(int fd, const void *buf, int len1);

int recv_all(int fd, void *buf, int len1, bool single_read);



#ifdef WIN32

/* Windows has different names for the same constants with the same values */

#define SHUT_RD   0

#define SHUT_WR   1

#define SHUT_RDWR 2

#endif



/* callback function for nonblocking connect

 * valid fd on success, negative error code on failure

 */

migration/qemu-file-unix.c

+19 −4
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ 
#include "qemu/sockets.h"

#include "block/coroutine.h"

#include "migration/qemu-file.h"

#include "migration/qemu-file-internal.h"



typedef struct QEMUFileSocket {

    int fd;
@@ -84,6 +85,17 @@ static int socket_close(void *opaque) 
    return 0;

}



static int socket_shutdown(void *opaque, bool rd, bool wr)

{

    QEMUFileSocket *s = opaque;



    if (shutdown(s->fd, rd ? (wr ? SHUT_RDWR : SHUT_RD) : SHUT_WR)) {

        return -errno;

    } else {

        return 0;

    }

}



static ssize_t unix_writev_buffer(void *opaque, struct iovec *iov, int iovcnt,

                                  int64_t pos)

{
@@ -194,13 +206,16 @@ QEMUFile *qemu_fdopen(int fd, const char *mode) 
static const QEMUFileOps socket_read_ops = {

    .get_fd     = socket_get_fd,

    .get_buffer = socket_get_buffer,

    .close =      socket_close

    .close      = socket_close,

    .shut_down  = socket_shutdown



};



static const QEMUFileOps socket_write_ops = {

    .get_fd        = socket_get_fd,

    .writev_buffer = socket_writev_buffer,

    .close =      socket_close

    .close         = socket_close,

    .shut_down     = socket_shutdown

};



QEMUFile *qemu_fopen_socket(int fd, const char *mode)

migration/qemu-file.c

+12 −0
Original line number Diff line number Diff line
@@ -30,6 +30,18 @@ 
#include "migration/qemu-file-internal.h"

#include "trace.h"



/*

 * Stop a file from being read/written - not all backing files can do this

 * typically only sockets can.

 */

int qemu_file_shutdown(QEMUFile *f)

{

    if (!f->ops->shut_down) {

        return -ENOSYS;

    }

    return f->ops->shut_down(f->opaque, true, true);

}



bool qemu_file_mode_is_not_valid(const char *mode)

{

    if (mode == NULL ||