From e1a8c9b67fc97d293211773edcae9e8e2f3367ab Mon Sep 17 00:00:00 2001 From: "Dr. David Alan Gilbert" Date: Thu, 8 Jan 2015 11:11:30 +0000 Subject: [PATCH] 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: Dr. David Alan Gilbert Reviewed-by: Paolo Bonzini Reviewed-by: Amit Shah Signed-off-by: Amit Shah --- include/migration/qemu-file.h | 10 ++++++++++ include/qemu/sockets.h | 7 +++++++ migration/qemu-file-unix.c | 23 +++++++++++++++++++---- migration/qemu-file.c | 12 ++++++++++++ 4 files changed, 48 insertions(+), 4 deletions(-) diff --git a/include/migration/qemu-file.h b/include/migration/qemu-file.h index 401676b..d843c00 100644 --- a/include/migration/qemu-file.h +++ b/include/migration/qemu-file.h @@ -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) diff --git a/include/qemu/sockets.h b/include/qemu/sockets.h index f47dae6..7992ece 100644 --- a/include/qemu/sockets.h +++ b/include/qemu/sockets.h @@ -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 */ diff --git a/migration/qemu-file-unix.c b/migration/qemu-file-unix.c index 9682396..bfbc086 100644 --- a/migration/qemu-file-unix.c +++ b/migration/qemu-file-unix.c @@ -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) { @@ -192,15 +204,18 @@ QEMUFile *qemu_fdopen(int fd, const char *mode) } static const QEMUFileOps socket_read_ops = { - .get_fd = socket_get_fd, + .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, + .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) diff --git a/migration/qemu-file.c b/migration/qemu-file.c index a7f2a34..edc2830 100644 --- a/migration/qemu-file.c +++ b/migration/qemu-file.c @@ -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 || -- 2.7.4