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Re: [PATCH v2 4/6] migration: Avoid multiple parsing of uri in migration
From: |
Daniel P . Berrangé |
Subject: |
Re: [PATCH v2 4/6] migration: Avoid multiple parsing of uri in migration code flow |
Date: |
Thu, 9 Feb 2023 12:09:21 +0000 |
User-agent: |
Mutt/2.2.9 (2022-11-12) |
On Wed, Feb 08, 2023 at 09:35:58AM +0000, Het Gala wrote:
> In existing senario, 'migrate' QAPI argument - string uri, is encoded
> twice to extract migration parameters for stream connection. This is
> not a good representation of migration wire protocol as it is a data
> encoding scheme within a data encoding scheme. Qemu should be able to
> directly work with results from QAPI without having to do a second
> level parsing.
> Modified 'migrate' QAPI design supports well defined MigrateChannel
> struct which plays important role in avoiding double encoding
> of uri strings.
>
> qemu_uri_parsing() parses uri string (kept for backward
> compatibility) and populate the MigrateChannel struct parameters.
> Migration code flow for all required migration transport types -
> socket, exec and rdma is modified.
>
> Suggested-by: Daniel P. Berrange <berrange@redhat.com>
> Suggested-by: Manish Mishra <manish.mishra@nutanix.com>
> Suggested-by: Aravind Retnakaran <aravind.retnakaran@nutanix.com>
> Signed-off-by: Het Gala <het.gala@nutanix.com>
> ---
> migration/exec.c | 31 ++++++++++++++++--
> migration/exec.h | 4 ++-
> migration/migration.c | 75 +++++++++++++++++++++++++++++++++++--------
> migration/rdma.c | 30 +++++------------
> migration/rdma.h | 3 +-
> migration/socket.c | 21 ++++--------
> migration/socket.h | 3 +-
> 7 files changed, 110 insertions(+), 57 deletions(-)
>
> diff --git a/migration/exec.c b/migration/exec.c
> index 375d2e1b54..4fa9819792 100644
> --- a/migration/exec.c
> +++ b/migration/exec.c
> @@ -23,14 +23,39 @@
> #include "migration.h"
> #include "io/channel-command.h"
> #include "trace.h"
> +#include "qapi/error.h"
>
>
> -void exec_start_outgoing_migration(MigrationState *s, const char *command,
> Error **errp)
> +void init_exec_array(strList *command, const char *argv[], Error **errp)
> +{
> + int i = 0;
> + strList *lst;
> +
> + for (lst = command; lst ; lst = lst->next) {
> + argv[i++] = lst->value;
> + }
> +
> + /*
> + * Considering exec command always has 3 arguments to execute
> + * a command directly from the bash itself.
> + */
> + if (i > 3) {
> + error_setg(errp, "exec accepts maximum of 3 arguments in the list");
> + return;
> + }
By the time this check fires, the for() loop above has already
done out of bounds writes on argv[].
> +
> + argv[i] = NULL;
> + return;
> +}
> +
> +void exec_start_outgoing_migration(MigrationState *s, strList *command,
> + Error **errp)
> {
> QIOChannel *ioc;
> - const char *argv[] = { "/bin/sh", "-c", command, NULL };
> + const char *argv[4];
> + init_exec_array(command, argv, errp);
If someone invokes 'migrate' with the old URI style, the
strList will be 3 elements, and thus argv[4] is safe.
If someone invokes 'migrate' with thue new MigrateChannel style,
the strList can be arbitrarily long and thus argv[4] will be
risk of overflow.
>
> - trace_migration_exec_outgoing(command);
> + trace_migration_exec_outgoing(argv[2]);
> ioc = QIO_CHANNEL(qio_channel_command_new_spawn(argv,
> O_RDWR,
> errp));
> diff --git a/migration/exec.h b/migration/exec.h
> index b210ffde7a..5b39ba6cbb 100644
> --- a/migration/exec.h
> +++ b/migration/exec.h
> @@ -19,8 +19,10 @@
>
> #ifndef QEMU_MIGRATION_EXEC_H
> #define QEMU_MIGRATION_EXEC_H
> +void init_exec_array(strList *command, const char *argv[], Error **errp);
> +
> void exec_start_incoming_migration(const char *host_port, Error **errp);
>
> -void exec_start_outgoing_migration(MigrationState *s, const char *host_port,
> +void exec_start_outgoing_migration(MigrationState *s, strList *host_port,
> Error **errp);
> #endif
> diff --git a/migration/migration.c b/migration/migration.c
> index f6dd8dbb03..accbf72a18 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -63,6 +63,7 @@
> #include "sysemu/cpus.h"
> #include "yank_functions.h"
> #include "sysemu/qtest.h"
> +#include "qemu/sockets.h"
> #include "ui/qemu-spice.h"
>
> #define MAX_THROTTLE (128 << 20) /* Migration transfer speed
> throttling */
> @@ -489,6 +490,44 @@ void migrate_add_address(SocketAddress *address)
> QAPI_CLONE(SocketAddress, address));
> }
>
> +static bool migrate_uri_parse(const char *uri,
> + MigrateChannel **channel,
> + Error **errp)
> +{
> + Error *local_err = NULL;
> + MigrateChannel *val = g_new0(MigrateChannel, 1);
> + MigrateAddress *addrs = g_new0(MigrateAddress, 1);
> + SocketAddress *saddr = g_new0(SocketAddress, 1);
> + InetSocketAddress *isock = g_new0(InetSocketAddress, 1);
> +
> + if (strstart(uri, "exec:", NULL)) {
> + addrs->transport = MIGRATE_TRANSPORT_EXEC;
> + addrs->u.exec.data = str_split_at_comma(uri + strlen("exec:"));
> + } else if (strstart(uri, "rdma:", NULL) &&
> + !inet_parse(isock, uri + strlen("rdma:"), errp)) {
> + addrs->transport = MIGRATE_TRANSPORT_RDMA;
> + addrs->u.rdma.data = isock;
> + } else if (strstart(uri, "tcp:", NULL) ||
> + strstart(uri, "unix:", NULL) ||
> + strstart(uri, "vsock:", NULL) ||
> + strstart(uri, "fd:", NULL)) {
> + addrs->transport = MIGRATE_TRANSPORT_SOCKET;
> + saddr = socket_parse(uri, &local_err);
> + addrs->u.socket.socket_type = saddr;
> + }
> +
> + val->channeltype = MIGRATE_CHANNEL_TYPE_MAIN;
> + val->addr = addrs;
> + *channel = val;
> +
> + if (local_err) {
> + error_propagate(errp, local_err);
> + return false;
> + }
> +
> + return true;
> +}
> +
> static void qemu_start_incoming_migration(const char *uri, Error **errp)
> {
> const char *p = NULL;
> @@ -2469,7 +2508,8 @@ void qmp_migrate(const char *uri, MigrateChannel
> *channel, bool has_blk,
> {
> Error *local_err = NULL;
> MigrationState *s = migrate_get_current();
> - const char *p = NULL;
> + MigrateAddress *addrs = g_new0(MigrateAddress, 1);
> + SocketAddress *saddr = g_new0(SocketAddress, 1);
>
> if (!migrate_prepare(s, has_blk && blk, has_inc && inc,
> has_resume && resume, errp)) {
> @@ -2490,22 +2530,29 @@ void qmp_migrate(const char *uri, MigrateChannel
> *channel, bool has_blk,
> error_setg(errp, "uri and channels options should be"
> "mutually exclusive");
> return;
> + } else if (uri && !migrate_uri_parse(uri, &channel, &local_err)) {
> + error_setg(errp, "Error parsing uri");
> + return;
> }
>
> migrate_protocol_allow_multi_channels(false);
> - if (strstart(uri, "tcp:", &p) ||
> - strstart(uri, "unix:", NULL) ||
> - strstart(uri, "vsock:", NULL)) {
> - migrate_protocol_allow_multi_channels(true);
> - socket_start_outgoing_migration(s, p ? p : uri, &local_err);
> -#ifdef CONFIG_RDMA
> - } else if (strstart(uri, "rdma:", &p)) {
> - rdma_start_outgoing_migration(s, p, &local_err);
> -#endif
> - } else if (strstart(uri, "exec:", &p)) {
> - exec_start_outgoing_migration(s, p, &local_err);
> - } else if (strstart(uri, "fd:", &p)) {
> - fd_start_outgoing_migration(s, p, &local_err);
> + addrs = channel->addr;
> + saddr = channel->addr->u.socket.socket_type;
> + if (addrs->transport == MIGRATE_TRANSPORT_SOCKET) {
> + if (saddr->type == SOCKET_ADDRESS_TYPE_INET ||
> + saddr->type == SOCKET_ADDRESS_TYPE_UNIX ||
> + saddr->type == SOCKET_ADDRESS_TYPE_VSOCK) {
> + migrate_protocol_allow_multi_channels(true);
> + socket_start_outgoing_migration(s, saddr, &local_err);
> + } else if (saddr->type == SOCKET_ADDRESS_TYPE_FD) {
> + fd_start_outgoing_migration(s, saddr->u.fd.str, &local_err);
> + }
> + #ifdef CONFIG_RDMA
> + } else if (addrs->transport == MIGRATE_TRANSPORT_RDMA) {
> + rdma_start_outgoing_migration(s, addrs->u.rdma.data, &local_err);
> + #endif
> + } else if (addrs->transport == MIGRATE_TRANSPORT_EXEC) {
> + exec_start_outgoing_migration(s, addrs->u.exec.data, &local_err);
> } else {
> if (!(has_resume && resume)) {
> yank_unregister_instance(MIGRATION_YANK_INSTANCE);
> diff --git a/migration/rdma.c b/migration/rdma.c
> index 288eadc2d2..48f49add6f 100644
> --- a/migration/rdma.c
> +++ b/migration/rdma.c
> @@ -316,7 +316,6 @@ typedef struct RDMALocalBlocks {
> typedef struct RDMAContext {
> char *host;
> int port;
> - char *host_port;
>
> RDMAWorkRequestData wr_data[RDMA_WRID_MAX];
>
> @@ -2449,9 +2448,7 @@ static void qemu_rdma_cleanup(RDMAContext *rdma)
> rdma->channel = NULL;
> }
> g_free(rdma->host);
> - g_free(rdma->host_port);
> rdma->host = NULL;
> - rdma->host_port = NULL;
> }
>
>
> @@ -2733,28 +2730,17 @@ static void
> qemu_rdma_return_path_dest_init(RDMAContext *rdma_return_path,
> rdma_return_path->is_return_path = true;
> }
>
> -static void *qemu_rdma_data_init(const char *host_port, Error **errp)
> +static void *qemu_rdma_data_init(InetSocketAddress *saddr, Error **errp)
> {
> RDMAContext *rdma = NULL;
> - InetSocketAddress *addr;
>
> - if (host_port) {
> + if (saddr) {
> rdma = g_new0(RDMAContext, 1);
> rdma->current_index = -1;
> rdma->current_chunk = -1;
>
> - addr = g_new(InetSocketAddress, 1);
> - if (!inet_parse(addr, host_port, NULL)) {
> - rdma->port = atoi(addr->port);
> - rdma->host = g_strdup(addr->host);
> - rdma->host_port = g_strdup(host_port);
> - } else {
> - ERROR(errp, "bad RDMA migration address '%s'", host_port);
> - g_free(rdma);
> - rdma = NULL;
> - }
> -
> - qapi_free_InetSocketAddress(addr);
> + rdma->host = g_strdup(saddr->host);
> + rdma->port = atoi(saddr->port);
> }
>
> return rdma;
> @@ -3354,6 +3340,7 @@ static int qemu_rdma_accept(RDMAContext *rdma)
> .private_data_len = sizeof(cap),
> };
> RDMAContext *rdma_return_path = NULL;
> + InetSocketAddress *isock = g_new0(InetSocketAddress, 1);
> struct rdma_cm_event *cm_event;
> struct ibv_context *verbs;
> int ret = -EINVAL;
> @@ -4152,14 +4139,13 @@ err:
> error_propagate(errp, local_err);
> if (rdma) {
> g_free(rdma->host);
> - g_free(rdma->host_port);
> }
> g_free(rdma);
> g_free(rdma_return_path);
> }
>
> void rdma_start_outgoing_migration(void *opaque,
> - const char *host_port, Error **errp)
> + InetSocketAddress *addr, Error **errp)
> {
> MigrationState *s = opaque;
> RDMAContext *rdma_return_path = NULL;
> @@ -4172,7 +4158,7 @@ void rdma_start_outgoing_migration(void *opaque,
> return;
> }
>
> - rdma = qemu_rdma_data_init(host_port, errp);
> + rdma = qemu_rdma_data_init(addr, errp);
> if (rdma == NULL) {
> goto err;
> }
> @@ -4193,7 +4179,7 @@ void rdma_start_outgoing_migration(void *opaque,
>
> /* RDMA postcopy need a separate queue pair for return path */
> if (migrate_postcopy()) {
> - rdma_return_path = qemu_rdma_data_init(host_port, errp);
> + rdma_return_path = qemu_rdma_data_init(addr, errp);
>
> if (rdma_return_path == NULL) {
> goto return_path_err;
> diff --git a/migration/rdma.h b/migration/rdma.h
> index de2ba09dc5..8d9978e1a9 100644
> --- a/migration/rdma.h
> +++ b/migration/rdma.h
> @@ -13,11 +13,12 @@
> * later. See the COPYING file in the top-level directory.
> *
> */
> +#include "io/channel-socket.h"
>
> #ifndef QEMU_MIGRATION_RDMA_H
> #define QEMU_MIGRATION_RDMA_H
>
> -void rdma_start_outgoing_migration(void *opaque, const char *host_port,
> +void rdma_start_outgoing_migration(void *opaque, InetSocketAddress *addr,
> Error **errp);
>
> void rdma_start_incoming_migration(const char *host_port, Error **errp);
> diff --git a/migration/socket.c b/migration/socket.c
> index e6fdf3c5e1..c751e0bfc1 100644
> --- a/migration/socket.c
> +++ b/migration/socket.c
> @@ -27,6 +27,8 @@
> #include "io/net-listener.h"
> #include "trace.h"
> #include "postcopy-ram.h"
> +#include "qapi/clone-visitor.h"
> +#include "qapi/qapi-visit-sockets.h"
>
> struct SocketOutgoingArgs {
> SocketAddress *saddr;
> @@ -107,19 +109,20 @@ out:
> object_unref(OBJECT(sioc));
> }
>
> -static void
> -socket_start_outgoing_migration_internal(MigrationState *s,
> +void socket_start_outgoing_migration(MigrationState *s,
> SocketAddress *saddr,
> Error **errp)
> {
> QIOChannelSocket *sioc = qio_channel_socket_new();
> struct SocketConnectData *data = g_new0(struct SocketConnectData, 1);
> + SocketAddress *addr = g_new0(SocketAddress, 1);
> + addr = QAPI_CLONE(SocketAddress, saddr);
>
> data->s = s;
>
> /* in case previous migration leaked it */
> qapi_free_SocketAddress(outgoing_args.saddr);
> - outgoing_args.saddr = saddr;
> + outgoing_args.saddr = addr;
>
> if (saddr->type == SOCKET_ADDRESS_TYPE_INET) {
> data->hostname = g_strdup(saddr->u.inet.host);
> @@ -134,18 +137,6 @@ socket_start_outgoing_migration_internal(MigrationState
> *s,
> NULL);
> }
>
> -void socket_start_outgoing_migration(MigrationState *s,
> - const char *str,
> - Error **errp)
> -{
> - Error *err = NULL;
> - SocketAddress *saddr = socket_parse(str, &err);
> - if (!err) {
> - socket_start_outgoing_migration_internal(s, saddr, &err);
> - }
> - error_propagate(errp, err);
> -}
> -
> static void socket_accept_incoming_migration(QIONetListener *listener,
> QIOChannelSocket *cioc,
> gpointer opaque)
> diff --git a/migration/socket.h b/migration/socket.h
> index dc54df4e6c..95c9c166ec 100644
> --- a/migration/socket.h
> +++ b/migration/socket.h
> @@ -19,6 +19,7 @@
>
> #include "io/channel.h"
> #include "io/task.h"
> +#include "io/channel-socket.h"
>
> void socket_send_channel_create(QIOTaskFunc f, void *data);
> QIOChannel *socket_send_channel_create_sync(Error **errp);
> @@ -26,6 +27,6 @@ int socket_send_channel_destroy(QIOChannel *send);
>
> void socket_start_incoming_migration(const char *str, Error **errp);
>
> -void socket_start_outgoing_migration(MigrationState *s, const char *str,
> +void socket_start_outgoing_migration(MigrationState *s, SocketAddress *saddr,
> Error **errp);
> #endif
> --
> 2.22.3
>
With regards,
Daniel
--
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[PATCH v2 2/6] migration: Updated QAPI format for 'migrate' qemu monitor command, Het Gala, 2023/02/08
- Re: [PATCH v2 2/6] migration: Updated QAPI format for 'migrate' qemu monitor command, Eric Blake, 2023/02/08
- Re: [PATCH v2 2/6] migration: Updated QAPI format for 'migrate' qemu monitor command, Het Gala, 2023/02/09
- Re: [PATCH v2 2/6] migration: Updated QAPI format for 'migrate' qemu monitor command, Daniel P . Berrangé, 2023/02/09
- Re: [PATCH v2 2/6] migration: Updated QAPI format for 'migrate' qemu monitor command, Het Gala, 2023/02/09
- Re: [PATCH v2 2/6] migration: Updated QAPI format for 'migrate' qemu monitor command, Daniel P . Berrangé, 2023/02/09
- Re: [PATCH v2 2/6] migration: Updated QAPI format for 'migrate' qemu monitor command, Het Gala, 2023/02/10