From f87fa77ca999f2f8d595156309222fa373218f1a Mon Sep 17 00:00:00 2001 From: Peter Krempa Date: Thu, 27 Jan 2022 16:48:00 +0100 Subject: [PATCH] lib: Introduce 'virDomainQemuMonitorCommandWithFiles' MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This API has the same semantics as 'virDomainQemuMonitorCommand' but accepts file descriptors which are then forwarded to qemu. Signed-off-by: Peter Krempa Reviewed-by: Ján Tomko --- include/libvirt/libvirt-qemu.h | 8 +++ src/driver-hypervisor.h | 10 ++++ src/libvirt-qemu.c | 89 +++++++++++++++++++++++++++++ src/libvirt_qemu.syms | 5 ++ src/qemu_protocol-structs | 9 +++ src/remote/qemu_protocol.x | 20 ++++++- src/remote/remote_daemon_dispatch.c | 62 ++++++++++++++++++++ src/remote/remote_driver.c | 57 ++++++++++++++++++ 8 files changed, 259 insertions(+), 1 deletion(-) diff --git a/include/libvirt/libvirt-qemu.h b/include/libvirt/libvirt-qemu.h index 0cc2872821..98f2ac3823 100644 --- a/include/libvirt/libvirt-qemu.h +++ b/include/libvirt/libvirt-qemu.h @@ -37,6 +37,14 @@ typedef enum { int virDomainQemuMonitorCommand(virDomainPtr domain, const char *cmd, char **result, unsigned int flags); +int virDomainQemuMonitorCommandWithFiles(virDomainPtr domain, + const char *cmd, + unsigned int ninfiles, + int *infiles, + unsigned int *noutfiles, + int **outfiles, + char **result, + unsigned int flags); virDomainPtr virDomainQemuAttach(virConnectPtr domain, unsigned int pid_value, diff --git a/src/driver-hypervisor.h b/src/driver-hypervisor.h index c83fb648a2..4423eb0885 100644 --- a/src/driver-hypervisor.h +++ b/src/driver-hypervisor.h @@ -874,6 +874,15 @@ typedef int const char *cmd, char **result, unsigned int flags); +typedef int +(*virDrvDomainQemuMonitorCommandWithFiles)(virDomainPtr domain, + const char *cmd, + unsigned int ninfiles, + int *infiles, + unsigned int *noutfiles, + int **outfiles, + char **result, + unsigned int flags); typedef char * (*virDrvDomainQemuAgentCommand)(virDomainPtr domain, @@ -1597,6 +1606,7 @@ struct _virHypervisorDriver { virDrvDomainRevertToSnapshot domainRevertToSnapshot; virDrvDomainSnapshotDelete domainSnapshotDelete; virDrvDomainQemuMonitorCommand domainQemuMonitorCommand; + virDrvDomainQemuMonitorCommandWithFiles domainQemuMonitorCommandWithFiles; virDrvDomainQemuAttach domainQemuAttach; virDrvDomainQemuAgentCommand domainQemuAgentCommand; virDrvConnectDomainQemuMonitorEventRegister connectDomainQemuMonitorEventRegister; diff --git a/src/libvirt-qemu.c b/src/libvirt-qemu.c index 1afb5fe529..9e80577b56 100644 --- a/src/libvirt-qemu.c +++ b/src/libvirt-qemu.c @@ -96,6 +96,95 @@ virDomainQemuMonitorCommand(virDomainPtr domain, const char *cmd, } +/** + * virDomainQemuMonitorCommandWithFiles: + * @domain: a domain object + * @cmd: the qemu monitor command string + * @ninfiles: number of filedescriptors passed in @infiles + * @infiles: filedescriptors to be passed to qemu with the command + * @noutfiles: if non-NULL filled with number of returned file descriptors + * @outfiles: if non-NULL filled with an array of returned file descriptors + * @result: a string returned by @cmd + * @flags: bitwise-or of supported virDomainQemuMonitorCommandFlags + * + * This API is QEMU specific, so it will only work with hypervisor + * connections to the QEMU driver with local connections using the unix socket. + * + * Send an arbitrary monitor command @cmd with file descriptors @infiles to + * @domain through the qemu monitor and optionally return file descriptors via + * @outfiles. There are several requirements to safely and successfully use + * this API: + * + * - A @cmd that queries state without making any modifications is safe + * - A @cmd that alters state that is also tracked by libvirt is unsafe, + * and may cause libvirtd to crash + * - A @cmd that alters state not tracked by the current version of + * libvirt is possible as a means to test new qemu features before + * they have support in libvirt, but no guarantees are made to safety + * + * If VIR_DOMAIN_QEMU_MONITOR_COMMAND_HMP is set, the command is + * considered to be a human monitor command and libvirt will automatically + * convert it into QMP if needed. In that case the @result will also + * be converted back from QMP. + * + * If successful, @result will be filled with the string output of the + * @cmd, and the caller must free this string. + * + * Returns 0 in case of success, -1 in case of failure + */ +int +virDomainQemuMonitorCommandWithFiles(virDomainPtr domain, + const char *cmd, + unsigned int ninfiles, + int *infiles, + unsigned int *noutfiles, + int **outfiles, + char **result, + unsigned int flags) +{ + virConnectPtr conn; + + VIR_DOMAIN_DEBUG(domain, + "cmd=%s, ninfiles=%u, infiles=%p, noutfiles=%p, outfiles=%p, result=%p, flags=0x%x", + cmd, ninfiles, infiles, noutfiles, outfiles, result, flags); + + virResetLastError(); + + virCheckDomainReturn(domain, -1); + conn = domain->conn; + + if (ninfiles > 0 || outfiles) { + int rc; + if ((rc = VIR_DRV_SUPPORTS_FEATURE(conn->driver, conn, + VIR_DRV_FEATURE_FD_PASSING) <= 0)) { + if (rc == 0) + virReportError(VIR_ERR_ARGUMENT_UNSUPPORTED, "%s", + _("fd passing is not supported by this connection")); + goto error; + } + } + + virCheckNonNullArgGoto(result, error); + virCheckReadOnlyGoto(conn->flags, error); + + if (conn->driver->domainQemuMonitorCommandWithFiles) { + int ret; + ret = conn->driver->domainQemuMonitorCommandWithFiles(domain, cmd, + ninfiles, infiles, + noutfiles, outfiles, + result, flags); + if (ret < 0) + goto error; + return ret; + } + + virReportUnsupportedError(); + + error: + virDispatchError(conn); + return -1; +} + /** * virDomainQemuAttach: * @conn: pointer to a hypervisor connection diff --git a/src/libvirt_qemu.syms b/src/libvirt_qemu.syms index 3a297e3a2b..182658bd0d 100644 --- a/src/libvirt_qemu.syms +++ b/src/libvirt_qemu.syms @@ -30,3 +30,8 @@ LIBVIRT_QEMU_1.2.3 { virConnectDomainQemuMonitorEventDeregister; virConnectDomainQemuMonitorEventRegister; } LIBVIRT_QEMU_0.10.0; + +LIBVIRT_QEMU_8.2.0 { + global: + virDomainQemuMonitorCommandWithFiles; +} LIBVIRT_QEMU_1.2.3; diff --git a/src/qemu_protocol-structs b/src/qemu_protocol-structs index 8501543cd9..ea0854385f 100644 --- a/src/qemu_protocol-structs +++ b/src/qemu_protocol-structs @@ -47,6 +47,14 @@ struct qemu_domain_monitor_event_msg { u_int micros; remote_string details; }; +struct qemu_domain_monitor_command_with_files_args { + remote_nonnull_domain dom; + remote_nonnull_string cmd; + u_int flags; +}; +struct qemu_domain_monitor_command_with_files_ret { + remote_nonnull_string result; +}; enum qemu_procedure { QEMU_PROC_DOMAIN_MONITOR_COMMAND = 1, QEMU_PROC_DOMAIN_ATTACH = 2, @@ -54,4 +62,5 @@ enum qemu_procedure { QEMU_PROC_CONNECT_DOMAIN_MONITOR_EVENT_REGISTER = 4, QEMU_PROC_CONNECT_DOMAIN_MONITOR_EVENT_DEREGISTER = 5, QEMU_PROC_DOMAIN_MONITOR_EVENT = 6, + QEMU_PROC_DOMAIN_MONITOR_COMMAND_WITH_FILES = 7, }; diff --git a/src/remote/qemu_protocol.x b/src/remote/qemu_protocol.x index 8ff5dc8568..c7f3abfcbf 100644 --- a/src/remote/qemu_protocol.x +++ b/src/remote/qemu_protocol.x @@ -79,6 +79,17 @@ struct qemu_domain_monitor_event_msg { remote_string details; }; +struct qemu_domain_monitor_command_with_files_args { + remote_nonnull_domain dom; + remote_nonnull_string cmd; + unsigned int flags; +}; + +struct qemu_domain_monitor_command_with_files_ret { + remote_nonnull_string result; +}; + + /* Define the program number, protocol version and procedure numbers here. */ const QEMU_PROGRAM = 0x20008087; const QEMU_PROTOCOL_VERSION = 1; @@ -151,5 +162,12 @@ enum qemu_procedure { * @generate: both * @acl: none */ - QEMU_PROC_DOMAIN_MONITOR_EVENT = 6 + QEMU_PROC_DOMAIN_MONITOR_EVENT = 6, + + /** + * @generate: none + * @priority: low + * @acl: domain:write + */ + QEMU_PROC_DOMAIN_MONITOR_COMMAND_WITH_FILES = 7 }; diff --git a/src/remote/remote_daemon_dispatch.c b/src/remote/remote_daemon_dispatch.c index 587cc0b3a5..510856024c 100644 --- a/src/remote/remote_daemon_dispatch.c +++ b/src/remote/remote_daemon_dispatch.c @@ -4684,6 +4684,68 @@ qemuDispatchDomainMonitorCommand(virNetServer *server G_GNUC_UNUSED, } +static int +qemuDispatchDomainMonitorCommandWithFiles(virNetServer *server G_GNUC_UNUSED, + virNetServerClient *client, + virNetMessage *msg, + struct virNetMessageError *rerr, + qemu_domain_monitor_command_with_files_args *args, + qemu_domain_monitor_command_with_files_ret *ret) +{ + virDomainPtr dom = NULL; + int *infiles = NULL; + unsigned int ninfiles = 0; + int *outfiles = NULL; + unsigned int noutfiles = 0; + int rv = -1; + virConnectPtr conn = remoteGetHypervisorConn(client); + size_t i; + + if (!conn) + goto cleanup; + + if (!(dom = get_nonnull_domain(conn, args->dom))) + goto cleanup; + + infiles = g_new0(int, msg->nfds); + for (i = 0; i < msg->nfds; i++) { + if ((infiles[i] = virNetMessageDupFD(msg, i)) < 0) + goto cleanup; + ninfiles++; + } + + /* This API can both receive FDs from the client and send FDs back, but 'msg' + * is being reused. Thus we must clear the list of FDs in it to prevent + * us sending back the FDs client sent us. */ + virNetMessageClearFDs(msg); + + if (virDomainQemuMonitorCommandWithFiles(dom, args->cmd, ninfiles, infiles, + &noutfiles, &outfiles, + &ret->result, args->flags) < 0) + goto cleanup; + + for (i = 0; i < noutfiles; i++) { + if (virNetMessageAddFD(msg, outfiles[i]) < 0) + goto cleanup; + } + + /* return 1 here to let virNetServerProgramDispatchCall know we are passing fds */ + if (noutfiles > 0) + rv = 1; + else + rv = 0; + + cleanup: + for (i = 0; i < noutfiles; i++) + VIR_FORCE_CLOSE(outfiles[i]); + + if (rv < 0) + virNetMessageSaveError(rerr); + virObjectUnref(dom); + return rv; +} + + static int remoteDispatchDomainMigrateBegin3(virNetServer *server G_GNUC_UNUSED, virNetServerClient *client, diff --git a/src/remote/remote_driver.c b/src/remote/remote_driver.c index d721da6d2d..d6295f32e9 100644 --- a/src/remote/remote_driver.c +++ b/src/remote/remote_driver.c @@ -5931,6 +5931,62 @@ remoteDomainQemuMonitorCommand(virDomainPtr domain, const char *cmd, } +static int +remoteDomainQemuMonitorCommandWithFiles(virDomainPtr domain, + const char *cmd, + unsigned int ninfiles, + int *infiles, + unsigned int *noutfiles, + int **outfiles, + char **result, + unsigned int flags) +{ + int rv = -1; + qemu_domain_monitor_command_with_files_args args; + qemu_domain_monitor_command_with_files_ret ret; + struct private_data *priv = domain->conn->privateData; + size_t rpc_noutfiles = 0; + g_autofree int *rpc_outfiles = NULL; + size_t i; + + remoteDriverLock(priv); + + make_nonnull_domain(&args.dom, domain); + args.cmd = (char *)cmd; + args.flags = flags; + + memset(&ret, 0, sizeof(ret)); + if (callFull(domain->conn, priv, REMOTE_CALL_QEMU, + infiles, ninfiles, &rpc_outfiles, &rpc_noutfiles, + QEMU_PROC_DOMAIN_MONITOR_COMMAND_WITH_FILES, + (xdrproc_t) xdr_qemu_domain_monitor_command_with_files_args, (char *) &args, + (xdrproc_t) xdr_qemu_domain_monitor_command_with_files_ret, (char *) &ret) == -1) + goto done; + + if (outfiles) + *outfiles = g_steal_pointer(&rpc_outfiles); + + if (noutfiles) + *noutfiles = rpc_noutfiles; + + *result = g_strdup(ret.result); + + rv = 0; + + xdr_free((xdrproc_t) xdr_qemu_domain_monitor_command_with_files_ret, (char *) &ret); + + done: + if (rpc_outfiles) { + for (i = 0; rpc_noutfiles < i; i++) { + VIR_FORCE_CLOSE(rpc_outfiles[i]); + } + } + + remoteDriverUnlock(priv); + return rv; +} + + static char * remoteDomainMigrateBegin3(virDomainPtr domain, const char *xmlin, @@ -8506,6 +8562,7 @@ static virHypervisorDriver hypervisor_driver = { .domainSnapshotHasMetadata = remoteDomainSnapshotHasMetadata, /* 0.9.13 */ .domainSnapshotDelete = remoteDomainSnapshotDelete, /* 0.8.0 */ .domainQemuMonitorCommand = remoteDomainQemuMonitorCommand, /* 0.8.3 */ + .domainQemuMonitorCommandWithFiles = remoteDomainQemuMonitorCommandWithFiles, /* 8.2.0 */ .domainQemuAttach = remoteDomainQemuAttach, /* 0.9.4 */ .domainQemuAgentCommand = remoteDomainQemuAgentCommand, /* 0.10.0 */ .connectDomainQemuMonitorEventRegister = remoteConnectDomainQemuMonitorEventRegister, /* 1.2.3 */