diff options
| -rw-r--r-- | nbd/client.c | 47 |
1 files changed, 33 insertions, 14 deletions
diff --git a/nbd/client.c b/nbd/client.c index 651e08cd3a..5d94e34760 100644 --- a/nbd/client.c +++ b/nbd/client.c @@ -75,6 +75,32 @@ static QTAILQ_HEAD(, NBDExport) exports = QTAILQ_HEAD_INITIALIZER(exports); */ +/* Discard length bytes from channel. Return -errno on failure, or + * the amount of bytes consumed. */ +static ssize_t drop_sync(QIOChannel *ioc, size_t size) +{ + ssize_t ret, dropped = size; + char small[1024]; + char *buffer; + + buffer = sizeof(small) < size ? small : g_malloc(MIN(65536, size)); + while (size > 0) { + ret = read_sync(ioc, buffer, MIN(65536, size)); + if (ret < 0) { + goto cleanup; + } + assert(ret <= size); + size -= ret; + } + ret = dropped; + + cleanup: + if (buffer != small) { + g_free(buffer); + } + return ret; +} + /* Send an option request. * * The request is for option @opt, with @data containing @len bytes of @@ -285,19 +311,12 @@ static int nbd_receive_list(QIOChannel *ioc, char **name, Error **errp) } (*name)[namelen] = '\0'; len -= namelen; - if (len) { - char *buf = g_malloc(len + 1); - if (read_sync(ioc, buf, len) != len) { - error_setg(errp, "failed to read export description"); - g_free(*name); - g_free(buf); - *name = NULL; - nbd_send_opt_abort(ioc); - return -1; - } - buf[len] = '\0'; - TRACE("Ignoring export description: %s", buf); - g_free(buf); + if (drop_sync(ioc, len) != len) { + error_setg(errp, "failed to read export description"); + g_free(*name); + *name = NULL; + nbd_send_opt_abort(ioc); + return -1; } } else { error_setg(errp, "Unexpected reply type %" PRIx32 " expected %x", @@ -577,7 +596,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags, } TRACE("Size is %" PRIu64 ", export flags %" PRIx16, *size, *flags); - if (read_sync(ioc, &buf, 124) != 124) { + if (drop_sync(ioc, 124) != 124) { error_setg(errp, "Failed to read reserved block"); goto fail; } |