From e6798f06a67a25def45a6636259de38cc38f1414 Mon Sep 17 00:00:00 2001 From: Vladimir Sementsov-Ogievskiy Date: Mon, 28 Jan 2019 19:58:30 +0300 Subject: [PATCH] nbd: generalize usage of nbd_read We generally do very similar things around nbd_read: error_prepend specifying what we have tried to read, and be_to_cpu conversion of integers. So, it seems reasonable to move common things to helper functions, which: 1. simplify code a bit 2. generalize nbd_read error descriptions, all starting with "Failed to read" 3. make it more difficult to forget to convert things from BE Signed-off-by: Vladimir Sementsov-Ogievskiy Reviewed-by: Eric Blake Message-Id: <20190128165830.165170-1-vsementsov@virtuozzo.com> [eblake: rename macro to DEF_NBD_READ_N and formatting tweaks; checkpatch has false positive complaint] Signed-off-by: Eric Blake --- block/nbd-client.c | 5 ++- include/block/nbd.h | 32 +++++++++++++++-- nbd/client.c | 88 +++++++++++++++------------------------------ nbd/common.c | 2 +- nbd/server.c | 27 +++++--------- 5 files changed, 71 insertions(+), 83 deletions(-) diff --git a/block/nbd-client.c b/block/nbd-client.c index 50a8dadd85..57f679ad4d 100644 --- a/block/nbd-client.c +++ b/block/nbd-client.c @@ -338,10 +338,9 @@ static int nbd_co_receive_offset_data_payload(NBDClientSession *s, return -EINVAL; } - if (nbd_read(s->ioc, &offset, sizeof(offset), errp) < 0) { + if (nbd_read64(s->ioc, &offset, "OFFSET_DATA offset", errp) < 0) { return -EIO; } - be64_to_cpus(&offset); data_size = chunk->length - sizeof(offset); assert(data_size); @@ -388,7 +387,7 @@ static coroutine_fn int nbd_co_receive_structured_payload( } *payload = g_new(char, len); - ret = nbd_read(s->ioc, *payload, len, errp); + ret = nbd_read(s->ioc, *payload, len, "structured payload", errp); if (ret < 0) { g_free(*payload); *payload = NULL; diff --git a/include/block/nbd.h b/include/block/nbd.h index 4faf394e34..96cfb1d7d5 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -23,6 +23,7 @@ #include "qapi/qapi-types-block.h" #include "io/channel-socket.h" #include "crypto/tlscreds.h" +#include "qapi/error.h" /* Handshake phase structs - this struct is passed on the wire */ @@ -336,11 +337,38 @@ void nbd_server_start(SocketAddress *addr, const char *tls_creds, * Reads @size bytes from @ioc. Returns 0 on success. */ static inline int nbd_read(QIOChannel *ioc, void *buffer, size_t size, - Error **errp) + const char *desc, Error **errp) { - return qio_channel_read_all(ioc, buffer, size, errp) < 0 ? -EIO : 0; + int ret = qio_channel_read_all(ioc, buffer, size, errp) < 0 ? -EIO : 0; + + if (ret < 0) { + if (desc) { + error_prepend(errp, "Failed to read %s: ", desc); + } + return -1; + } + + return 0; } +#define DEF_NBD_READ_N(bits) \ +static inline int nbd_read##bits(QIOChannel *ioc, \ + uint##bits##_t *val, \ + const char *desc, Error **errp) \ +{ \ + if (nbd_read(ioc, val, sizeof(*val), desc, errp) < 0) { \ + return -1; \ + } \ + *val = be##bits##_to_cpu(*val); \ + return 0; \ +} + +DEF_NBD_READ_N(16) /* Defines nbd_read16(). */ +DEF_NBD_READ_N(32) /* Defines nbd_read32(). */ +DEF_NBD_READ_N(64) /* Defines nbd_read64(). */ + +#undef DEF_NBD_READ_N + static inline bool nbd_reply_is_simple(NBDReply *reply) { return reply->magic == NBD_SIMPLE_REPLY_MAGIC; diff --git a/nbd/client.c b/nbd/client.c index 8a083c2f42..10a52ad7d0 100644 --- a/nbd/client.c +++ b/nbd/client.c @@ -113,8 +113,7 @@ static int nbd_receive_option_reply(QIOChannel *ioc, uint32_t opt, NBDOptionReply *reply, Error **errp) { QEMU_BUILD_BUG_ON(sizeof(*reply) != 20); - if (nbd_read(ioc, reply, sizeof(*reply), errp) < 0) { - error_prepend(errp, "failed to read option reply: "); + if (nbd_read(ioc, reply, sizeof(*reply), "option reply", errp) < 0) { nbd_send_opt_abort(ioc); return -1; } @@ -166,8 +165,8 @@ static int nbd_handle_reply_err(QIOChannel *ioc, NBDOptionReply *reply, goto cleanup; } msg = g_malloc(reply->length + 1); - if (nbd_read(ioc, msg, reply->length, errp) < 0) { - error_prepend(errp, "failed to read option error %" PRIu32 + if (nbd_read(ioc, msg, reply->length, NULL, errp) < 0) { + error_prepend(errp, "Failed to read option error %" PRIu32 " (%s) message: ", reply->type, nbd_rep_lookup(reply->type)); goto cleanup; @@ -284,12 +283,10 @@ static int nbd_receive_list(QIOChannel *ioc, char **name, char **description, nbd_send_opt_abort(ioc); return -1; } - if (nbd_read(ioc, &namelen, sizeof(namelen), errp) < 0) { - error_prepend(errp, "failed to read option name length: "); + if (nbd_read32(ioc, &namelen, "option name length", errp) < 0) { nbd_send_opt_abort(ioc); return -1; } - namelen = be32_to_cpu(namelen); len -= sizeof(namelen); if (len < namelen) { error_setg(errp, "incorrect option name length"); @@ -298,8 +295,7 @@ static int nbd_receive_list(QIOChannel *ioc, char **name, char **description, } local_name = g_malloc(namelen + 1); - if (nbd_read(ioc, local_name, namelen, errp) < 0) { - error_prepend(errp, "failed to read export name: "); + if (nbd_read(ioc, local_name, namelen, "export name", errp) < 0) { nbd_send_opt_abort(ioc); goto out; } @@ -307,8 +303,7 @@ static int nbd_receive_list(QIOChannel *ioc, char **name, char **description, len -= namelen; if (len) { local_desc = g_malloc(len + 1); - if (nbd_read(ioc, local_desc, len, errp) < 0) { - error_prepend(errp, "failed to read export description: "); + if (nbd_read(ioc, local_desc, len, "export description", errp) < 0) { nbd_send_opt_abort(ioc); goto out; } @@ -410,13 +405,11 @@ static int nbd_opt_info_or_go(QIOChannel *ioc, uint32_t opt, nbd_send_opt_abort(ioc); return -1; } - if (nbd_read(ioc, &type, sizeof(type), errp) < 0) { - error_prepend(errp, "failed to read info type: "); + if (nbd_read16(ioc, &type, "info type", errp) < 0) { nbd_send_opt_abort(ioc); return -1; } len -= sizeof(type); - type = be16_to_cpu(type); switch (type) { case NBD_INFO_EXPORT: if (len != sizeof(info->size) + sizeof(info->flags)) { @@ -425,18 +418,14 @@ static int nbd_opt_info_or_go(QIOChannel *ioc, uint32_t opt, nbd_send_opt_abort(ioc); return -1; } - if (nbd_read(ioc, &info->size, sizeof(info->size), errp) < 0) { - error_prepend(errp, "failed to read info size: "); + if (nbd_read64(ioc, &info->size, "info size", errp) < 0) { nbd_send_opt_abort(ioc); return -1; } - info->size = be64_to_cpu(info->size); - if (nbd_read(ioc, &info->flags, sizeof(info->flags), errp) < 0) { - error_prepend(errp, "failed to read info flags: "); + if (nbd_read16(ioc, &info->flags, "info flags", errp) < 0) { nbd_send_opt_abort(ioc); return -1; } - info->flags = be16_to_cpu(info->flags); trace_nbd_receive_negotiate_size_flags(info->size, info->flags); break; @@ -447,27 +436,23 @@ static int nbd_opt_info_or_go(QIOChannel *ioc, uint32_t opt, nbd_send_opt_abort(ioc); return -1; } - if (nbd_read(ioc, &info->min_block, sizeof(info->min_block), - errp) < 0) { - error_prepend(errp, "failed to read info minimum block size: "); + if (nbd_read32(ioc, &info->min_block, "info minimum block size", + errp) < 0) { nbd_send_opt_abort(ioc); return -1; } - info->min_block = be32_to_cpu(info->min_block); if (!is_power_of_2(info->min_block)) { error_setg(errp, "server minimum block size %" PRIu32 " is not a power of two", info->min_block); nbd_send_opt_abort(ioc); return -1; } - if (nbd_read(ioc, &info->opt_block, sizeof(info->opt_block), - errp) < 0) { - error_prepend(errp, - "failed to read info preferred block size: "); + if (nbd_read32(ioc, &info->opt_block, "info preferred block size", + errp) < 0) + { nbd_send_opt_abort(ioc); return -1; } - info->opt_block = be32_to_cpu(info->opt_block); if (!is_power_of_2(info->opt_block) || info->opt_block < info->min_block) { error_setg(errp, "server preferred block size %" PRIu32 @@ -475,13 +460,12 @@ static int nbd_opt_info_or_go(QIOChannel *ioc, uint32_t opt, nbd_send_opt_abort(ioc); return -1; } - if (nbd_read(ioc, &info->max_block, sizeof(info->max_block), - errp) < 0) { - error_prepend(errp, "failed to read info maximum block size: "); + if (nbd_read32(ioc, &info->max_block, "info maximum block size", + errp) < 0) + { nbd_send_opt_abort(ioc); return -1; } - info->max_block = be32_to_cpu(info->max_block); if (info->max_block < info->min_block) { error_setg(errp, "server maximum block size %" PRIu32 " is not valid", info->max_block); @@ -731,14 +715,13 @@ static int nbd_receive_one_meta_context(QIOChannel *ioc, return -1; } - if (nbd_read(ioc, &local_id, sizeof(local_id), errp) < 0) { + if (nbd_read32(ioc, &local_id, "context id", errp) < 0) { return -1; } - local_id = be32_to_cpu(local_id); reply.length -= sizeof(local_id); local_name = g_malloc(reply.length + 1); - if (nbd_read(ioc, local_name, reply.length, errp) < 0) { + if (nbd_read(ioc, local_name, reply.length, "context name", errp) < 0) { g_free(local_name); return -1; } @@ -896,11 +879,9 @@ static int nbd_start_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, return -EINVAL; } - if (nbd_read(ioc, &magic, sizeof(magic), errp) < 0) { - error_prepend(errp, "Failed to read initial magic: "); + if (nbd_read64(ioc, &magic, "initial magic", errp) < 0) { return -EINVAL; } - magic = be64_to_cpu(magic); trace_nbd_receive_negotiate_magic(magic); if (magic != NBD_INIT_MAGIC) { @@ -908,11 +889,9 @@ static int nbd_start_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, return -EINVAL; } - if (nbd_read(ioc, &magic, sizeof(magic), errp) < 0) { - error_prepend(errp, "Failed to read server magic: "); + if (nbd_read64(ioc, &magic, "server magic", errp) < 0) { return -EINVAL; } - magic = be64_to_cpu(magic); trace_nbd_receive_negotiate_magic(magic); if (magic == NBD_OPTS_MAGIC) { @@ -920,11 +899,9 @@ static int nbd_start_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, uint16_t globalflags; bool fixedNewStyle = false; - if (nbd_read(ioc, &globalflags, sizeof(globalflags), errp) < 0) { - error_prepend(errp, "Failed to read server flags: "); + if (nbd_read16(ioc, &globalflags, "server flags", errp) < 0) { return -EINVAL; } - globalflags = be16_to_cpu(globalflags); trace_nbd_receive_negotiate_server_flags(globalflags); if (globalflags & NBD_FLAG_FIXED_NEWSTYLE) { fixedNewStyle = true; @@ -992,17 +969,13 @@ static int nbd_negotiate_finish_oldstyle(QIOChannel *ioc, NBDExportInfo *info, { uint32_t oldflags; - if (nbd_read(ioc, &info->size, sizeof(info->size), errp) < 0) { - error_prepend(errp, "Failed to read export length: "); + if (nbd_read64(ioc, &info->size, "export length", errp) < 0) { return -EINVAL; } - info->size = be64_to_cpu(info->size); - if (nbd_read(ioc, &oldflags, sizeof(oldflags), errp) < 0) { - error_prepend(errp, "Failed to read export flags: "); + if (nbd_read32(ioc, &oldflags, "export flags", errp) < 0) { return -EINVAL; } - oldflags = be32_to_cpu(oldflags); if (oldflags & ~0xffff) { error_setg(errp, "Unexpected export flags %0x" PRIx32, oldflags); return -EINVAL; @@ -1079,17 +1052,13 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, } /* Read the response */ - if (nbd_read(ioc, &info->size, sizeof(info->size), errp) < 0) { - error_prepend(errp, "Failed to read export length: "); + if (nbd_read64(ioc, &info->size, "export length", errp) < 0) { return -EINVAL; } - info->size = be64_to_cpu(info->size); - if (nbd_read(ioc, &info->flags, sizeof(info->flags), errp) < 0) { - error_prepend(errp, "Failed to read export flags: "); + if (nbd_read16(ioc, &info->flags, "export flags", errp) < 0) { return -EINVAL; } - info->flags = be16_to_cpu(info->flags); break; case 0: /* oldstyle, parse length and flags */ if (*info->name) { @@ -1379,7 +1348,7 @@ static int nbd_receive_simple_reply(QIOChannel *ioc, NBDSimpleReply *reply, assert(reply->magic == NBD_SIMPLE_REPLY_MAGIC); ret = nbd_read(ioc, (uint8_t *)reply + sizeof(reply->magic), - sizeof(*reply) - sizeof(reply->magic), errp); + sizeof(*reply) - sizeof(reply->magic), "reply", errp); if (ret < 0) { return ret; } @@ -1404,7 +1373,8 @@ static int nbd_receive_structured_reply_chunk(QIOChannel *ioc, assert(chunk->magic == NBD_STRUCTURED_REPLY_MAGIC); ret = nbd_read(ioc, (uint8_t *)chunk + sizeof(chunk->magic), - sizeof(*chunk) - sizeof(chunk->magic), errp); + sizeof(*chunk) - sizeof(chunk->magic), "structured chunk", + errp); if (ret < 0) { return ret; } diff --git a/nbd/common.c b/nbd/common.c index 41f5ed8d9f..cc8b278e54 100644 --- a/nbd/common.c +++ b/nbd/common.c @@ -31,7 +31,7 @@ int nbd_drop(QIOChannel *ioc, size_t size, Error **errp) buffer = sizeof(small) >= size ? small : g_malloc(MIN(65536, size)); while (size > 0) { ssize_t count = MIN(65536, size); - ret = nbd_read(ioc, buffer, MIN(65536, size), errp); + ret = nbd_read(ioc, buffer, MIN(65536, size), NULL, errp); if (ret < 0) { goto cleanup; diff --git a/nbd/server.c b/nbd/server.c index cb0d5634fa..838c150d8c 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -438,8 +438,7 @@ static int nbd_negotiate_handle_export_name(NBDClient *client, error_setg(errp, "Bad length received"); return -EINVAL; } - if (nbd_read(client->ioc, name, client->optlen, errp) < 0) { - error_prepend(errp, "read failed: "); + if (nbd_read(client->ioc, name, client->optlen, "export name", errp) < 0) { return -EIO; } name[client->optlen] = '\0'; @@ -1046,11 +1045,9 @@ static int nbd_negotiate_options(NBDClient *client, uint16_t myflags, ... Rest of request */ - if (nbd_read(client->ioc, &flags, sizeof(flags), errp) < 0) { - error_prepend(errp, "read failed: "); + if (nbd_read32(client->ioc, &flags, "flags", errp) < 0) { return -EIO; } - flags = be32_to_cpu(flags); trace_nbd_negotiate_options_flags(flags); if (flags & NBD_FLAG_C_FIXED_NEWSTYLE) { fixedNewstyle = true; @@ -1070,30 +1067,23 @@ static int nbd_negotiate_options(NBDClient *client, uint16_t myflags, uint32_t option, length; uint64_t magic; - if (nbd_read(client->ioc, &magic, sizeof(magic), errp) < 0) { - error_prepend(errp, "read failed: "); + if (nbd_read64(client->ioc, &magic, "opts magic", errp) < 0) { return -EINVAL; } - magic = be64_to_cpu(magic); trace_nbd_negotiate_options_check_magic(magic); if (magic != NBD_OPTS_MAGIC) { error_setg(errp, "Bad magic received"); return -EINVAL; } - if (nbd_read(client->ioc, &option, - sizeof(option), errp) < 0) { - error_prepend(errp, "read failed: "); + if (nbd_read32(client->ioc, &option, "option", errp) < 0) { return -EINVAL; } - option = be32_to_cpu(option); client->opt = option; - if (nbd_read(client->ioc, &length, sizeof(length), errp) < 0) { - error_prepend(errp, "read failed: "); + if (nbd_read32(client->ioc, &length, "option length", errp) < 0) { return -EINVAL; } - length = be32_to_cpu(length); assert(!client->optlen); client->optlen = length; @@ -1306,7 +1296,7 @@ static int nbd_receive_request(QIOChannel *ioc, NBDRequest *request, uint32_t magic; int ret; - ret = nbd_read(ioc, buf, sizeof(buf), errp); + ret = nbd_read(ioc, buf, sizeof(buf), "request", errp); if (ret < 0) { return ret; } @@ -2111,8 +2101,9 @@ static int nbd_co_receive_request(NBDRequestData *req, NBDRequest *request, } } if (request->type == NBD_CMD_WRITE) { - if (nbd_read(client->ioc, req->data, request->len, errp) < 0) { - error_prepend(errp, "reading from socket failed: "); + if (nbd_read(client->ioc, req->data, request->len, "CMD_WRITE data", + errp) < 0) + { return -EIO; } req->complete = true;