diff options
Diffstat (limited to 'nbd')
| -rw-r--r-- | nbd/client.c | 255 | ||||
| -rw-r--r-- | nbd/nbd-internal.h | 2 |
2 files changed, 109 insertions, 148 deletions
diff --git a/nbd/client.c b/nbd/client.c index fe24d31ec6..e78000a28a 100644 --- a/nbd/client.c +++ b/nbd/client.c @@ -75,64 +75,128 @@ static QTAILQ_HEAD(, NBDExport) exports = QTAILQ_HEAD_INITIALIZER(exports); */ +/* Send an option request. + * + * The request is for option @opt, with @data containing @len bytes of + * additional payload for the request (@len may be -1 to treat @data as + * a C string; and @data may be NULL if @len is 0). + * Return 0 if successful, -1 with errp set if it is impossible to + * continue. */ +static int nbd_send_option_request(QIOChannel *ioc, uint32_t opt, + uint32_t len, const char *data, + Error **errp) +{ + nbd_option req; + QEMU_BUILD_BUG_ON(sizeof(req) != 16); + + if (len == -1) { + req.length = len = strlen(data); + } + TRACE("Sending option request %" PRIu32", len %" PRIu32, opt, len); + + stq_be_p(&req.magic, NBD_OPTS_MAGIC); + stl_be_p(&req.option, opt); + stl_be_p(&req.length, len); + + if (write_sync(ioc, &req, sizeof(req)) != sizeof(req)) { + error_setg(errp, "Failed to send option request header"); + return -1; + } + + if (len && write_sync(ioc, (char *) data, len) != len) { + error_setg(errp, "Failed to send option request data"); + return -1; + } + + return 0; +} + +/* Receive the header of an option reply, which should match the given + * opt. Read through the length field, but NOT the length bytes of + * payload. Return 0 if successful, -1 with errp set if it is + * impossible to continue. */ +static int nbd_receive_option_reply(QIOChannel *ioc, uint32_t opt, + nbd_opt_reply *reply, Error **errp) +{ + QEMU_BUILD_BUG_ON(sizeof(*reply) != 20); + if (read_sync(ioc, reply, sizeof(*reply)) != sizeof(*reply)) { + error_setg(errp, "failed to read option reply"); + return -1; + } + be64_to_cpus(&reply->magic); + be32_to_cpus(&reply->option); + be32_to_cpus(&reply->type); + be32_to_cpus(&reply->length); + + TRACE("Received option reply %" PRIx32", type %" PRIx32", len %" PRIu32, + reply->option, reply->type, reply->length); -/* If type represents success, return 1 without further action. - * If type represents an error reply, consume the rest of the packet on ioc. - * Then return 0 for unsupported (so the client can fall back to - * other approaches), or -1 with errp set for other errors. + if (reply->magic != NBD_REP_MAGIC) { + error_setg(errp, "Unexpected option reply magic"); + return -1; + } + if (reply->option != opt) { + error_setg(errp, "Unexpected option type %x expected %x", + reply->option, opt); + return -1; + } + return 0; +} + +/* If reply represents success, return 1 without further action. + * If reply represents an error, consume the optional payload of + * the packet on ioc. Then return 0 for unsupported (so the client + * can fall back to other approaches), or -1 with errp set for other + * errors. */ -static int nbd_handle_reply_err(QIOChannel *ioc, uint32_t opt, uint32_t type, +static int nbd_handle_reply_err(QIOChannel *ioc, nbd_opt_reply *reply, Error **errp) { - uint32_t len; char *msg = NULL; int result = -1; - if (!(type & (1 << 31))) { + if (!(reply->type & (1 << 31))) { return 1; } - if (read_sync(ioc, &len, sizeof(len)) != sizeof(len)) { - error_setg(errp, "failed to read option length"); - return -1; - } - len = be32_to_cpu(len); - if (len) { - if (len > NBD_MAX_BUFFER_SIZE) { + if (reply->length) { + if (reply->length > NBD_MAX_BUFFER_SIZE) { error_setg(errp, "server's error message is too long"); goto cleanup; } - msg = g_malloc(len + 1); - if (read_sync(ioc, msg, len) != len) { + msg = g_malloc(reply->length + 1); + if (read_sync(ioc, msg, reply->length) != reply->length) { error_setg(errp, "failed to read option error message"); goto cleanup; } - msg[len] = '\0'; + msg[reply->length] = '\0'; } - switch (type) { + switch (reply->type) { case NBD_REP_ERR_UNSUP: TRACE("server doesn't understand request %" PRIx32 - ", attempting fallback", opt); + ", attempting fallback", reply->option); result = 0; goto cleanup; case NBD_REP_ERR_POLICY: - error_setg(errp, "Denied by server for option %" PRIx32, opt); + error_setg(errp, "Denied by server for option %" PRIx32, + reply->option); break; case NBD_REP_ERR_INVALID: - error_setg(errp, "Invalid data length for option %" PRIx32, opt); + error_setg(errp, "Invalid data length for option %" PRIx32, + reply->option); break; case NBD_REP_ERR_TLS_REQD: error_setg(errp, "TLS negotiation required before option %" PRIx32, - opt); + reply->option); break; default: error_setg(errp, "Unknown error code when asking for option %" PRIx32, - opt); + reply->option); break; } @@ -147,58 +211,29 @@ static int nbd_handle_reply_err(QIOChannel *ioc, uint32_t opt, uint32_t type, static int nbd_receive_list(QIOChannel *ioc, char **name, Error **errp) { - uint64_t magic; - uint32_t opt; - uint32_t type; + nbd_opt_reply reply; uint32_t len; uint32_t namelen; int error; *name = NULL; - if (read_sync(ioc, &magic, sizeof(magic)) != sizeof(magic)) { - error_setg(errp, "failed to read list option magic"); - return -1; - } - magic = be64_to_cpu(magic); - if (magic != NBD_REP_MAGIC) { - error_setg(errp, "Unexpected option list magic"); - return -1; - } - if (read_sync(ioc, &opt, sizeof(opt)) != sizeof(opt)) { - error_setg(errp, "failed to read list option"); - return -1; - } - opt = be32_to_cpu(opt); - if (opt != NBD_OPT_LIST) { - error_setg(errp, "Unexpected option type %" PRIx32 " expected %x", - opt, NBD_OPT_LIST); - return -1; - } - - if (read_sync(ioc, &type, sizeof(type)) != sizeof(type)) { - error_setg(errp, "failed to read list option type"); + if (nbd_receive_option_reply(ioc, NBD_OPT_LIST, &reply, errp) < 0) { return -1; } - type = be32_to_cpu(type); - error = nbd_handle_reply_err(ioc, opt, type, errp); + error = nbd_handle_reply_err(ioc, &reply, errp); if (error <= 0) { return error; } + len = reply.length; - if (read_sync(ioc, &len, sizeof(len)) != sizeof(len)) { - error_setg(errp, "failed to read option length"); - return -1; - } - len = be32_to_cpu(len); - - if (type == NBD_REP_ACK) { + if (reply.type == NBD_REP_ACK) { if (len != 0) { error_setg(errp, "length too long for option end"); return -1; } - } else if (type == NBD_REP_SERVER) { + } else if (reply.type == NBD_REP_SERVER) { if (len < sizeof(namelen) || len > NBD_MAX_BUFFER_SIZE) { - error_setg(errp, "incorrect option length"); + error_setg(errp, "incorrect option length %" PRIu32, len); return -1; } if (read_sync(ioc, &namelen, sizeof(namelen)) != sizeof(namelen)) { @@ -240,7 +275,7 @@ static int nbd_receive_list(QIOChannel *ioc, char **name, Error **errp) } } else { error_setg(errp, "Unexpected reply type %" PRIx32 " expected %x", - type, NBD_REP_SERVER); + reply.type, NBD_REP_SERVER); return -1; } return 1; @@ -251,24 +286,10 @@ static int nbd_receive_query_exports(QIOChannel *ioc, const char *wantname, Error **errp) { - uint64_t magic = cpu_to_be64(NBD_OPTS_MAGIC); - uint32_t opt = cpu_to_be32(NBD_OPT_LIST); - uint32_t length = 0; bool foundExport = false; TRACE("Querying export list"); - if (write_sync(ioc, &magic, sizeof(magic)) != sizeof(magic)) { - error_setg(errp, "Failed to send list option magic"); - return -1; - } - - if (write_sync(ioc, &opt, sizeof(opt)) != sizeof(opt)) { - error_setg(errp, "Failed to send list option number"); - return -1; - } - - if (write_sync(ioc, &length, sizeof(length)) != sizeof(length)) { - error_setg(errp, "Failed to send list option length"); + if (nbd_send_option_request(ioc, NBD_OPT_LIST, 0, NULL, errp) < 0) { return -1; } @@ -314,72 +335,29 @@ static QIOChannel *nbd_receive_starttls(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, const char *hostname, Error **errp) { - uint64_t magic = cpu_to_be64(NBD_OPTS_MAGIC); - uint32_t opt = cpu_to_be32(NBD_OPT_STARTTLS); - uint32_t length = 0; - uint32_t type; + nbd_opt_reply reply; QIOChannelTLS *tioc; struct NBDTLSHandshakeData data = { 0 }; TRACE("Requesting TLS from server"); - if (write_sync(ioc, &magic, sizeof(magic)) != sizeof(magic)) { - error_setg(errp, "Failed to send option magic"); - return NULL; - } - - if (write_sync(ioc, &opt, sizeof(opt)) != sizeof(opt)) { - error_setg(errp, "Failed to send option number"); - return NULL; - } - - if (write_sync(ioc, &length, sizeof(length)) != sizeof(length)) { - error_setg(errp, "Failed to send option length"); - return NULL; - } - - TRACE("Getting TLS reply from server1"); - if (read_sync(ioc, &magic, sizeof(magic)) != sizeof(magic)) { - error_setg(errp, "failed to read option magic"); - return NULL; - } - magic = be64_to_cpu(magic); - if (magic != NBD_REP_MAGIC) { - error_setg(errp, "Unexpected option magic"); - return NULL; - } - TRACE("Getting TLS reply from server2"); - if (read_sync(ioc, &opt, sizeof(opt)) != sizeof(opt)) { - error_setg(errp, "failed to read option"); - return NULL; - } - opt = be32_to_cpu(opt); - if (opt != NBD_OPT_STARTTLS) { - error_setg(errp, "Unexpected option type %" PRIx32 " expected %x", - opt, NBD_OPT_STARTTLS); + if (nbd_send_option_request(ioc, NBD_OPT_STARTTLS, 0, NULL, errp) < 0) { return NULL; } TRACE("Getting TLS reply from server"); - if (read_sync(ioc, &type, sizeof(type)) != sizeof(type)) { - error_setg(errp, "failed to read option type"); + if (nbd_receive_option_reply(ioc, NBD_OPT_STARTTLS, &reply, errp) < 0) { return NULL; } - type = be32_to_cpu(type); - if (type != NBD_REP_ACK) { + + if (reply.type != NBD_REP_ACK) { error_setg(errp, "Server rejected request to start TLS %" PRIx32, - type); + reply.type); return NULL; } - TRACE("Getting TLS reply from server"); - if (read_sync(ioc, &length, sizeof(length)) != sizeof(length)) { - error_setg(errp, "failed to read option length"); - return NULL; - } - length = be32_to_cpu(length); - if (length != 0) { + if (reply.length != 0) { error_setg(errp, "Start TLS response was not zero %" PRIu32, - length); + reply.length); return NULL; } @@ -467,8 +445,6 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags, if (magic == NBD_OPTS_MAGIC) { uint32_t clientflags = 0; - uint32_t opt; - uint32_t namesize; uint16_t globalflags; bool fixedNewStyle = false; @@ -518,28 +494,13 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags, goto fail; } } - /* write the export name */ - magic = cpu_to_be64(magic); - if (write_sync(ioc, &magic, sizeof(magic)) != sizeof(magic)) { - error_setg(errp, "Failed to send export name magic"); - goto fail; - } - opt = cpu_to_be32(NBD_OPT_EXPORT_NAME); - if (write_sync(ioc, &opt, sizeof(opt)) != sizeof(opt)) { - error_setg(errp, "Failed to send export name option number"); - goto fail; - } - namesize = cpu_to_be32(strlen(name)); - if (write_sync(ioc, &namesize, sizeof(namesize)) != - sizeof(namesize)) { - error_setg(errp, "Failed to send export name length"); - goto fail; - } - if (write_sync(ioc, (char *)name, strlen(name)) != strlen(name)) { - error_setg(errp, "Failed to send export name"); + /* write the export name request */ + if (nbd_send_option_request(ioc, NBD_OPT_EXPORT_NAME, -1, name, + errp) < 0) { goto fail; } + /* Read the response */ if (read_sync(ioc, &s, sizeof(s)) != sizeof(s)) { error_setg(errp, "Failed to read export length"); goto fail; diff --git a/nbd/nbd-internal.h b/nbd/nbd-internal.h index 99e51571a2..dd57e18833 100644 --- a/nbd/nbd-internal.h +++ b/nbd/nbd-internal.h @@ -62,7 +62,7 @@ #define NBD_REPLY_MAGIC 0x67446698 #define NBD_OPTS_MAGIC 0x49484156454F5054LL #define NBD_CLIENT_MAGIC 0x0000420281861253LL -#define NBD_REP_MAGIC 0x3e889045565a9LL +#define NBD_REP_MAGIC 0x0003e889045565a9LL #define NBD_SET_SOCK _IO(0xab, 0) #define NBD_SET_BLKSIZE _IO(0xab, 1) |