Commit 33897dc7 authored by Nick Thomas's avatar Nick Thomas Committed by Kevin Wolf
Browse files

NBD device: Separate out parsing configuration and opening sockets. 



We also change the way the file parameter is parsed so IPv6 IP
addresses can be used, e.g.: "drive=nbd:[::1]:5000"

Signed-off-by: default avatarNick Thomas <nick@bytemark.co.uk>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent c12504ce

block/nbd.c

+102 −55
Original line number Diff line number Diff line
@@ -29,96 +29,152 @@ 
#include "qemu-common.h"

#include "nbd.h"

#include "module.h"

#include "qemu_socket.h"



#include <sys/types.h>

#include <unistd.h>



#define EN_OPTSTR ":exportname="



/* #define DEBUG_NBD */



#if defined(DEBUG_NBD)

#define logout(fmt, ...) \

                fprintf(stderr, "nbd\t%-24s" fmt, __func__, ##__VA_ARGS__)

#else

#define logout(fmt, ...) ((void)0)

#endif



typedef struct BDRVNBDState {

    int sock;

    off_t size;

    size_t blocksize;

    char *export_name; /* An NBD server may export several devices */



    /* If it begins with  '/', this is a UNIX domain socket. Otherwise,

     * it's a string of the form <hostname|ip4|\[ip6\]>:port

     */

    char *host_spec;

} BDRVNBDState;



static int nbd_open(BlockDriverState *bs, const char* filename, int flags)

static int nbd_config(BDRVNBDState *s, const char *filename, int flags)

{

    BDRVNBDState *s = bs->opaque;

    uint32_t nbdflags;



    char *file;

    char *name;

    const char *host;

    char *export_name;

    const char *host_spec;

    const char *unixpath;

    int sock;

    off_t size;

    size_t blocksize;

    int ret;

    int err = -EINVAL;



    file = qemu_strdup(filename);



    name = strstr(file, EN_OPTSTR);

    if (name) {

        if (name[strlen(EN_OPTSTR)] == 0) {

    export_name = strstr(file, EN_OPTSTR);

    if (export_name) {

        if (export_name[strlen(EN_OPTSTR)] == 0) {

            goto out;

        }

        name[0] = 0;

        name += strlen(EN_OPTSTR);

        export_name[0] = 0; /* truncate 'file' */

        export_name += strlen(EN_OPTSTR);

        s->export_name = qemu_strdup(export_name);

    }



    if (!strstart(file, "nbd:", &host)) {

    /* extract the host_spec - fail if it's not nbd:... */

    if (!strstart(file, "nbd:", &host_spec)) {

        goto out;

    }



    if (strstart(host, "unix:", &unixpath)) {



        if (unixpath[0] != '/') {

    /* are we a UNIX or TCP socket? */

    if (strstart(host_spec, "unix:", &unixpath)) {

        if (unixpath[0] != '/') { /* We demand  an absolute path*/

            goto out;

        }



        sock = unix_socket_outgoing(unixpath);



        s->host_spec = qemu_strdup(unixpath);

    } else {

        uint16_t port = NBD_DEFAULT_PORT;

        char *p, *r;

        char hostname[128];



        pstrcpy(hostname, 128, host);

        s->host_spec = qemu_strdup(host_spec);

    }



        p = strchr(hostname, ':');

        if (p != NULL) {

            *p = '\0';

            p++;

    err = 0;



            port = strtol(p, &r, 0);

            if (r == p) {

                goto out;

out:

    qemu_free(file);

    if (err != 0) {

        qemu_free(s->export_name);

        qemu_free(s->host_spec);

    }

    return err;

}



        sock = tcp_socket_outgoing(hostname, port);

static int nbd_establish_connection(BlockDriverState *bs)

{

    BDRVNBDState *s = bs->opaque;

    int sock;

    int ret;

    off_t size;

    size_t blocksize;

    uint32_t nbdflags;



    if (s->host_spec[0] == '/') {

        sock = unix_socket_outgoing(s->host_spec);

    } else {

        sock = tcp_socket_outgoing_spec(s->host_spec);

    }



    /* Failed to establish connection */

    if (sock == -1) {

        err = -errno;

        goto out;

        logout("Failed to establish connection to NBD server\n");

        return -errno;

    }



    ret = nbd_receive_negotiate(sock, name, &nbdflags, &size, &blocksize);

    /* NBD handshake */

    ret = nbd_receive_negotiate(sock, s->export_name, &nbdflags, &size,

                                &blocksize);

    if (ret == -1) {

        err = -errno;

        goto out;

        logout("Failed to negotiate with the NBD server\n");

        closesocket(sock);

        return -errno;

    }



    /* Now that we're connected, set the socket to be non-blocking */

    socket_set_nonblock(sock);



    s->sock = sock;

    s->size = size;

    s->blocksize = blocksize;

    err = 0;



out:

    qemu_free(file);

    return err;

    logout("Established connection with NBD server\n");

    return 0;

}



static void nbd_teardown_connection(BlockDriverState *bs)

{

    BDRVNBDState *s = bs->opaque;

    struct nbd_request request;



    request.type = NBD_CMD_DISC;

    request.handle = (uint64_t)(intptr_t)bs;

    request.from = 0;

    request.len = 0;

    nbd_send_request(s->sock, &request);



    closesocket(s->sock);

}



static int nbd_open(BlockDriverState *bs, const char* filename, int flags)

{

    BDRVNBDState *s = bs->opaque;

    int result;



    /* Pop the config into our state object. Exit if invalid. */

    result = nbd_config(s, filename, flags);

    if (result != 0) {

        return result;

    }



    /* establish TCP connection, return error if it fails

     * TODO: Configurable retry-until-timeout behaviour.

     */

    result = nbd_establish_connection(bs);



    return result;

}



static int nbd_read(BlockDriverState *bs, int64_t sector_num,
@@ -183,16 +239,7 @@ static int nbd_write(BlockDriverState *bs, int64_t sector_num, 


static void nbd_close(BlockDriverState *bs)

{

    BDRVNBDState *s = bs->opaque;

    struct nbd_request request;



    request.type = NBD_CMD_DISC;

    request.handle = (uint64_t)(intptr_t)bs;

    request.from = 0;

    request.len = 0;

    nbd_send_request(s->sock, &request);



    close(s->sock);

    nbd_teardown_connection(bs);

}



static int64_t nbd_getlength(BlockDriverState *bs)