Date: Thu, 1 Jun 2023 21:02:28 GMT From: Baptiste Daroussin <bapt@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 8a2af0b469b6 - main - nlsysevent: add a genetlink(4) module to report kernel events Message-ID: <202306012102.351L2SHn061499@gitrepo.freebsd.org>
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The branch main has been updated by bapt: URL: https://cgit.FreeBSD.org/src/commit/?id=8a2af0b469b6d65ee48f2352ca56225b36d32342 commit 8a2af0b469b6d65ee48f2352ca56225b36d32342 Author: Baptiste Daroussin <bapt@FreeBSD.org> AuthorDate: 2023-06-01 21:02:06 +0000 Commit: Baptiste Daroussin <bapt@FreeBSD.org> CommitDate: 2023-06-01 21:02:06 +0000 nlsysevent: add a genetlink(4) module to report kernel events Hooked to devctl_notify, this allows consumers to received events by subscribing to a system over a generic netlink protocol Reviewed by: imp, melifaro Differential Revision: https://reviews.freebsd.org/D37574 --- sys/modules/Makefile | 1 + sys/modules/nlsysevent/Makefile | 11 +++ sys/netlink/netlink_sysevent.c | 168 ++++++++++++++++++++++++++++++++++++++++ sys/netlink/netlink_sysevent.h | 40 ++++++++++ 4 files changed, 220 insertions(+) diff --git a/sys/modules/Makefile b/sys/modules/Makefile index b9867f25df4e..f14dd383221f 100644 --- a/sys/modules/Makefile +++ b/sys/modules/Makefile @@ -282,6 +282,7 @@ SUBDIR= \ nfsd \ nfslockd \ nfssvc \ + nlsysevent \ nge \ nmdm \ nullfs \ diff --git a/sys/modules/nlsysevent/Makefile b/sys/modules/nlsysevent/Makefile new file mode 100644 index 000000000000..d7d2100e3e66 --- /dev/null +++ b/sys/modules/nlsysevent/Makefile @@ -0,0 +1,11 @@ +# $FreeBSD$ + +.PATH: ${SRCTOP}/sys/netlink/ + +KMOD= nlsysevent +SRCS= netlink_sysevent.c + +CFLAGS+= -I${SRCTOP}/sys/contrib/netlink +EXPORT_SYMS= yes + +.include <bsd.kmod.mk> diff --git a/sys/netlink/netlink_sysevent.c b/sys/netlink/netlink_sysevent.c new file mode 100644 index 000000000000..67f18a3e2fe7 --- /dev/null +++ b/sys/netlink/netlink_sysevent.c @@ -0,0 +1,168 @@ +/*- + * SPDX-License-Identifier: BSD-2-Clause + * + * Copyright (c) 2023 Baptiste Daroussin <bapt@FreeBSD.org> + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <sys/param.h> +#include <sys/types.h> +#include <sys/devctl.h> +#include <sys/errno.h> +#include <sys/module.h> +#include <sys/kernel.h> +#include <sys/malloc.h> +#include <net/vnet.h> +#include <netlink/netlink.h> +#include <netlink/netlink_ctl.h> +#include <netlink/netlink_generic.h> + +#include "netlink_sysevent.h" + +#define DEBUG_MOD_NAME nl_sysevent +#define DEBUG_MAX_LEVEL LOG_DEBUG3 +#include <netlink/netlink_debug.h> +_DECLARE_DEBUG(LOG_INFO); + +MALLOC_DEFINE(M_NLSE, "nlsysevent", "Memory used for Netlink sysevent"); +#define NLSE_FAMILY_NAME "nlsysevent" +static uint32_t ctrl_family_id; + +#define MAX_SYSEVENTS 64 +static struct sysevent { + char *name; + uint32_t id; +} sysevents[MAX_SYSEVENTS] = {}; + +static void +sysevent_write(struct sysevent *se, const char *subsystem, const char *type, + const char *data) +{ + struct nl_writer nw = {}; + + if (!nlmsg_get_group_writer(&nw, NLMSG_LARGE, NETLINK_GENERIC, se->id)) { + NL_LOG(LOG_DEBUG, "error allocating group writer"); + return; + } + struct nlmsghdr hdr = { .nlmsg_type = ctrl_family_id }; + if (!nlmsg_reply(&nw, &hdr, sizeof(struct genlmsghdr))) { + return; + } + + struct genlmsghdr *ghdr = nlmsg_reserve_object(&nw, struct genlmsghdr); + if (ghdr == NULL) { + NL_LOG(LOG_DEBUG, "unable to allocate memory"); + return; + } + ghdr->version = 0; + ghdr->cmd = 0; + ghdr->reserved = 0; + nlattr_add_string(&nw, NLSE_ATTR_SYSTEM, se->name); + nlattr_add_string(&nw, NLSE_ATTR_SUBSYSTEM, subsystem); + nlattr_add_string(&nw, NLSE_ATTR_TYPE, type); + if (data != NULL) + nlattr_add_string(&nw, NLSE_ATTR_DATA, data); + nlmsg_end(&nw); + nlmsg_flush(&nw); +} + +static void +sysevent_send(const char *system, const char *subsystem, const char *type, + const char *data) +{ + struct sysevent *se = NULL; + + for (size_t i = 0; i < MAX_SYSEVENTS; i++) { + if (sysevents[i].name == NULL) { + sysevents[i].name = strdup(system, M_NLSE); + sysevents[i].id = genl_register_group(NLSE_FAMILY_NAME, + system); + se = &sysevents[i]; + break; + } + if (strcmp(sysevents[i].name, system) == 0) { + se = &sysevents[i]; + break; + } + } + if (se == NULL) { + NL_LOG(LOG_WARNING, "impossible to add the event %s, " + "too many events\n", system); + return; + } + + CURVNET_SET(vnet0); + sysevent_write(se, subsystem, type, data); + CURVNET_RESTORE(); +} + +static void +nlsysevent_load(void) +{ + devctl_set_notify_hook(sysevent_send); + ctrl_family_id = genl_register_family(NLSE_FAMILY_NAME, 0, 2, NLSE_ATTR_MAX); + for (size_t i = 0; i < nitems(devctl_systems); i++) { + if (i >= MAX_SYSEVENTS) { + NL_LOG(LOG_WARNING, "impossible to add the event %s, too many events\n", devctl_systems[i]); + continue; + } + sysevents[i].name = strdup(devctl_systems[i], M_NLSE); + sysevents[i].id = genl_register_group(NLSE_FAMILY_NAME, devctl_systems[i]); + } +} + +static void +nlsysevent_unload(void) +{ + devctl_unset_notify_hook(); + genl_unregister_family(NLSE_FAMILY_NAME); + for (size_t i = 0; i < MAX_SYSEVENTS; i++) { + if (sysevents[i].name == NULL) + break; + free(sysevents[i].name, M_NLSE); + } +} + +static int +nlsysevent_loader(module_t mod __unused, int what, void *priv __unused) +{ + int err = 0; + + switch (what) { + case MOD_LOAD: + nlsysevent_load(); + break; + case MOD_UNLOAD: + nlsysevent_unload(); + break; + default: + err = EOPNOTSUPP; + break; + } + return (err); +} +static moduledata_t nlsysevent_mod = { "nlsysevent", nlsysevent_loader, NULL}; + +DECLARE_MODULE(nlsysevent, nlsysevent_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); +MODULE_DEPEND(nlsysevent, netlink, 1, 1, 1); +MODULE_VERSION(nlsysevent, 1); diff --git a/sys/netlink/netlink_sysevent.h b/sys/netlink/netlink_sysevent.h new file mode 100644 index 000000000000..23288d2dd5c3 --- /dev/null +++ b/sys/netlink/netlink_sysevent.h @@ -0,0 +1,40 @@ +/*- + * SPDX-License-Identifier: BSD-2-Clause + * + * Copyright (c) 2023 Baptiste Daroussin <bapt@FreeBSD.org> + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#ifndef _NETLINK_SYSEVENT_H_ +#define _NETLINK_SYSEVENT_H_ + +enum { + NLSE_ATTR_UNSPEC = 0, + NLSE_ATTR_SYSTEM = 1, + NLSE_ATTR_SUBSYSTEM = 2, + NLSE_ATTR_TYPE = 3, + NLSE_ATTR_DATA = 4, + __NLSE_ATTR_MAX, +}; +#define NLSE_ATTR_MAX (__NLSE_ATTR_MAX -1) +#endif
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