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Diffstat (limited to '')
| -rw-r--r-- | lib/netns_linux.c | 612 |
1 files changed, 612 insertions, 0 deletions
diff --git a/lib/netns_linux.c b/lib/netns_linux.c new file mode 100644 index 0000000..43c0d8c --- /dev/null +++ b/lib/netns_linux.c @@ -0,0 +1,612 @@ +/* + * NS functions. + * Copyright (C) 2014 6WIND S.A. + * + * This file is part of GNU Zebra. + * + * GNU Zebra is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published + * by the Free Software Foundation; either version 2, or (at your + * option) any later version. + * + * GNU Zebra is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; see the file COPYING; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include <zebra.h> + +#ifdef HAVE_NETNS +#undef _GNU_SOURCE +#define _GNU_SOURCE + +#include <sched.h> +#endif + +/* for basename */ +#include <libgen.h> + +#include "if.h" +#include "ns.h" +#include "log.h" +#include "memory.h" +#include "command.h" +#include "vty.h" +#include "vrf.h" +#include "lib_errors.h" + +DEFINE_MTYPE_STATIC(LIB, NS, "NetNS Context"); +DEFINE_MTYPE_STATIC(LIB, NS_NAME, "NetNS Name"); + +static inline int ns_compare(const struct ns *ns, const struct ns *ns2); +static struct ns *ns_lookup_name_internal(const char *name); + +RB_GENERATE(ns_head, ns, entry, ns_compare) + +static struct ns_head ns_tree = RB_INITIALIZER(&ns_tree); + +static struct ns *default_ns; +static int ns_current_ns_fd; +static int ns_default_ns_fd; + +static int ns_debug; + +struct ns_map_nsid { + RB_ENTRY(ns_map_nsid) id_entry; + ns_id_t ns_id_external; + ns_id_t ns_id; +}; + +static inline int ns_map_compare(const struct ns_map_nsid *a, + const struct ns_map_nsid *b) +{ + return (a->ns_id - b->ns_id); +} + +RB_HEAD(ns_map_nsid_head, ns_map_nsid); +RB_PROTOTYPE(ns_map_nsid_head, ns_map_nsid, id_entry, ns_map_compare); +RB_GENERATE(ns_map_nsid_head, ns_map_nsid, id_entry, ns_map_compare); +static struct ns_map_nsid_head ns_map_nsid_list = + RB_INITIALIZER(&ns_map_nsid_list); + +static ns_id_t ns_id_external_numbering; + + +#ifndef CLONE_NEWNET +#define CLONE_NEWNET 0x40000000 +/* New network namespace (lo, device, names sockets, etc) */ +#endif + +#ifndef HAVE_SETNS +static inline int setns(int fd, int nstype) +{ +#ifdef __NR_setns + return syscall(__NR_setns, fd, nstype); +#else + errno = EINVAL; + return -1; +#endif +} +#endif /* !HAVE_SETNS */ + +#ifdef HAVE_NETNS +static int have_netns_enabled = -1; +#endif /* HAVE_NETNS */ + +static int have_netns(void) +{ +#ifdef HAVE_NETNS + if (have_netns_enabled < 0) { + int fd = open(NS_DEFAULT_NAME, O_RDONLY); + + if (fd < 0) + have_netns_enabled = 0; + else { + have_netns_enabled = 1; + close(fd); + } + } + return have_netns_enabled; +#else + return 0; +#endif +} + +/* Holding NS hooks */ +static struct ns_master { + int (*ns_new_hook)(struct ns *ns); + int (*ns_delete_hook)(struct ns *ns); + int (*ns_enable_hook)(struct ns *ns); + int (*ns_disable_hook)(struct ns *ns); +} ns_master = { + 0, +}; + +static int ns_is_enabled(struct ns *ns); + +static inline int ns_compare(const struct ns *a, const struct ns *b) +{ + return (a->ns_id - b->ns_id); +} + +/* Look up a NS by identifier. */ +static struct ns *ns_lookup_internal(ns_id_t ns_id) +{ + struct ns ns; + + ns.ns_id = ns_id; + return RB_FIND(ns_head, &ns_tree, &ns); +} + +/* Look up a NS by name */ +static struct ns *ns_lookup_name_internal(const char *name) +{ + struct ns *ns = NULL; + + RB_FOREACH (ns, ns_head, &ns_tree) { + if (ns->name != NULL) { + if (strcmp(name, ns->name) == 0) + return ns; + } + } + return NULL; +} + +static struct ns *ns_get_created_internal(struct ns *ns, char *name, + ns_id_t ns_id) +{ + int created = 0; + /* + * Initialize interfaces. + */ + if (!ns && !name && ns_id != NS_UNKNOWN) + ns = ns_lookup_internal(ns_id); + if (!ns && name) + ns = ns_lookup_name_internal(name); + if (!ns) { + ns = XCALLOC(MTYPE_NS, sizeof(struct ns)); + ns->ns_id = ns_id; + if (name) + ns->name = XSTRDUP(MTYPE_NS_NAME, name); + ns->fd = -1; + RB_INSERT(ns_head, &ns_tree, ns); + created = 1; + } + if (ns_id != ns->ns_id) { + RB_REMOVE(ns_head, &ns_tree, ns); + ns->ns_id = ns_id; + RB_INSERT(ns_head, &ns_tree, ns); + } + if (!created) + return ns; + if (ns_debug) { + if (ns->ns_id != NS_UNKNOWN) + zlog_info("NS %u is created.", ns->ns_id); + else + zlog_info("NS %s is created.", ns->name); + } + if (ns_master.ns_new_hook) + (*ns_master.ns_new_hook)(ns); + return ns; +} + +/* + * Enable a NS - that is, let the NS be ready to use. + * The NS_ENABLE_HOOK callback will be called to inform + * that they can allocate resources in this NS. + * + * RETURN: 1 - enabled successfully; otherwise, 0. + */ +static int ns_enable_internal(struct ns *ns, void (*func)(ns_id_t, void *)) +{ + if (!ns_is_enabled(ns)) { + if (have_netns()) { + ns->fd = open(ns->name, O_RDONLY); + } else { + ns->fd = -2; + /* Remember ns_enable_hook has been called */ + errno = -ENOTSUP; + } + + if (!ns_is_enabled(ns)) { + flog_err_sys(EC_LIB_SYSTEM_CALL, + "Can not enable NS %u: %s!", ns->ns_id, + safe_strerror(errno)); + return 0; + } + + /* Non default NS. leave */ + if (ns->ns_id == NS_UNKNOWN) { + flog_err(EC_LIB_NS, + "Can not enable NS %s %u: Invalid NSID", + ns->name, ns->ns_id); + return 0; + } + if (func) + func(ns->ns_id, (void *)ns->vrf_ctxt); + if (ns_debug) { + if (have_netns()) + zlog_info("NS %u is associated with NETNS %s.", + ns->ns_id, ns->name); + zlog_info("NS %u is enabled.", ns->ns_id); + } + /* zebra first receives NS enable event, + * then VRF enable event + */ + if (ns_master.ns_enable_hook) + (*ns_master.ns_enable_hook)(ns); + } + + return 1; +} + +/* + * Check whether the NS is enabled - that is, whether the NS + * is ready to allocate resources. Currently there's only one + * type of resource: socket. + */ +static int ns_is_enabled(struct ns *ns) +{ + if (have_netns()) + return ns && ns->fd >= 0; + else + return ns && ns->fd == -2 && ns->ns_id == NS_DEFAULT; +} + +/* + * Disable a NS - that is, let the NS be unusable. + * The NS_DELETE_HOOK callback will be called to inform + * that they must release the resources in the NS. + */ +static void ns_disable_internal(struct ns *ns) +{ + if (ns_is_enabled(ns)) { + if (ns_debug) + zlog_info("NS %u is to be disabled.", ns->ns_id); + + if (ns_master.ns_disable_hook) + (*ns_master.ns_disable_hook)(ns); + + if (have_netns()) + close(ns->fd); + + ns->fd = -1; + } +} + +/* VRF list existence check by name. */ +static struct ns_map_nsid *ns_map_nsid_lookup_by_nsid(ns_id_t ns_id) +{ + struct ns_map_nsid ns_map; + + ns_map.ns_id = ns_id; + return RB_FIND(ns_map_nsid_head, &ns_map_nsid_list, &ns_map); +} + +ns_id_t ns_map_nsid_with_external(ns_id_t ns_id, bool map) +{ + struct ns_map_nsid *ns_map; + vrf_id_t ns_id_external; + + ns_map = ns_map_nsid_lookup_by_nsid(ns_id); + if (ns_map && !map) { + ns_id_external = ns_map->ns_id_external; + RB_REMOVE(ns_map_nsid_head, &ns_map_nsid_list, ns_map); + return ns_id_external; + } + if (ns_map) + return ns_map->ns_id_external; + ns_map = XCALLOC(MTYPE_NS, sizeof(struct ns_map_nsid)); + /* increase vrf_id + * default vrf is the first one : 0 + */ + ns_map->ns_id_external = ns_id_external_numbering++; + ns_map->ns_id = ns_id; + RB_INSERT(ns_map_nsid_head, &ns_map_nsid_list, ns_map); + return ns_map->ns_id_external; +} + +struct ns *ns_get_created(struct ns *ns, char *name, ns_id_t ns_id) +{ + return ns_get_created_internal(ns, name, ns_id); +} + +int ns_have_netns(void) +{ + return have_netns(); +} + +/* Delete a NS. This is called in ns_terminate(). */ +void ns_delete(struct ns *ns) +{ + if (ns_debug) + zlog_info("NS %u is to be deleted.", ns->ns_id); + + ns_disable(ns); + + if (ns_master.ns_delete_hook) + (*ns_master.ns_delete_hook)(ns); + + /* + * I'm not entirely sure if the vrf->iflist + * needs to be moved into here or not. + */ + // if_terminate (&ns->iflist); + + RB_REMOVE(ns_head, &ns_tree, ns); + XFREE(MTYPE_NS_NAME, ns->name); + + XFREE(MTYPE_NS, ns); +} + +/* Look up the data pointer of the specified VRF. */ +void *ns_info_lookup(ns_id_t ns_id) +{ + struct ns *ns = ns_lookup_internal(ns_id); + + return ns ? ns->info : NULL; +} + +/* Look up a NS by name */ +struct ns *ns_lookup_name(const char *name) +{ + return ns_lookup_name_internal(name); +} + +int ns_enable(struct ns *ns, void (*func)(ns_id_t, void *)) +{ + return ns_enable_internal(ns, func); +} + +void ns_disable(struct ns *ns) +{ + ns_disable_internal(ns); +} + +struct ns *ns_lookup(ns_id_t ns_id) +{ + return ns_lookup_internal(ns_id); +} + +void ns_walk_func(int (*func)(struct ns *, + void *param_in, + void **param_out), + void *param_in, + void **param_out) +{ + struct ns *ns = NULL; + int ret; + + RB_FOREACH (ns, ns_head, &ns_tree) { + ret = func(ns, param_in, param_out); + if (ret == NS_WALK_STOP) + return; + } +} + +const char *ns_get_name(struct ns *ns) +{ + if (!ns) + return NULL; + return ns->name; +} + +/* Add a NS hook. Please add hooks before calling ns_init(). */ +void ns_add_hook(int type, int (*func)(struct ns *)) +{ + switch (type) { + case NS_NEW_HOOK: + ns_master.ns_new_hook = func; + break; + case NS_DELETE_HOOK: + ns_master.ns_delete_hook = func; + break; + case NS_ENABLE_HOOK: + ns_master.ns_enable_hook = func; + break; + case NS_DISABLE_HOOK: + ns_master.ns_disable_hook = func; + break; + default: + break; + } +} + +/* + * NS realization with NETNS + */ + +char *ns_netns_pathname(struct vty *vty, const char *name) +{ + static char pathname[PATH_MAX]; + char *result; + char *check_base; + + if (name[0] == '/') /* absolute pathname */ + result = realpath(name, pathname); + else { + /* relevant pathname */ + char tmp_name[PATH_MAX]; + + snprintf(tmp_name, sizeof(tmp_name), "%s/%s", NS_RUN_DIR, name); + result = realpath(tmp_name, pathname); + } + + if (!result) { + if (vty) + vty_out(vty, "Invalid pathname for %s: %s\n", + pathname, + safe_strerror(errno)); + else + flog_warn(EC_LIB_LINUX_NS, + "Invalid pathname for %s: %s", pathname, + safe_strerror(errno)); + return NULL; + } + check_base = basename(pathname); + if (check_base != NULL && strlen(check_base) + 1 > NS_NAMSIZ) { + if (vty) + vty_out(vty, "NS name (%s) invalid: too long (>%d)\n", + check_base, NS_NAMSIZ - 1); + else + flog_warn(EC_LIB_LINUX_NS, + "NS name (%s) invalid: too long (>%d)", + check_base, NS_NAMSIZ - 1); + return NULL; + } + return pathname; +} + +void ns_init(void) +{ + static int ns_initialised; + + ns_debug = 0; + /* silently return as initialisation done */ + if (ns_initialised == 1) + return; + errno = 0; + if (have_netns()) + ns_default_ns_fd = open(NS_DEFAULT_NAME, O_RDONLY); + else { + ns_default_ns_fd = -1; + default_ns = NULL; + } + ns_current_ns_fd = -1; + ns_initialised = 1; +} + +/* Initialize NS module. */ +void ns_init_management(ns_id_t default_ns_id, ns_id_t internal_ns) +{ + int fd; + + ns_init(); + default_ns = ns_get_created_internal(NULL, NULL, default_ns_id); + if (!default_ns) { + flog_err(EC_LIB_NS, "%s: failed to create the default NS!", + __func__); + exit(1); + } + if (have_netns()) { + fd = open(NS_DEFAULT_NAME, O_RDONLY); + default_ns->fd = fd; + } + default_ns->internal_ns_id = internal_ns; + + /* Set the default NS name. */ + default_ns->name = XSTRDUP(MTYPE_NS_NAME, NS_DEFAULT_NAME); + if (ns_debug) + zlog_info("%s: default NSID is %u", __func__, + default_ns->ns_id); + + /* Enable the default NS. */ + if (!ns_enable(default_ns, NULL)) { + flog_err(EC_LIB_NS, "%s: failed to enable the default NS!", + __func__); + exit(1); + } +} + +/* Terminate NS module. */ +void ns_terminate(void) +{ + struct ns *ns; + + while (!RB_EMPTY(ns_head, &ns_tree)) { + ns = RB_ROOT(ns_head, &ns_tree); + + ns_delete(ns); + } +} + +int ns_switch_to_netns(const char *name) +{ + int ret; + int fd; + + if (name == NULL) + return -1; + if (ns_default_ns_fd == -1) + return -1; + fd = open(name, O_RDONLY); + if (fd == -1) { + errno = EINVAL; + return -1; + } + ret = setns(fd, CLONE_NEWNET); + ns_current_ns_fd = fd; + close(fd); + return ret; +} + +/* returns 1 if switch() was not called before + * return status of setns() otherwise + */ +int ns_switchback_to_initial(void) +{ + if (ns_current_ns_fd != -1 && ns_default_ns_fd != -1) { + int ret; + + ret = setns(ns_default_ns_fd, CLONE_NEWNET); + ns_current_ns_fd = -1; + return ret; + } + /* silently ignore if setns() is not called */ + return 1; +} + +/* Create a socket for the NS. */ +int ns_socket(int domain, int type, int protocol, ns_id_t ns_id) +{ + struct ns *ns = ns_lookup(ns_id); + int ret; + + if (!ns || !ns_is_enabled(ns)) { + errno = EINVAL; + return -1; + } + if (have_netns()) { + ret = (ns_id != NS_DEFAULT) ? setns(ns->fd, CLONE_NEWNET) : 0; + if (ret >= 0) { + ret = socket(domain, type, protocol); + if (ns_id != NS_DEFAULT) { + setns(ns_lookup(NS_DEFAULT)->fd, CLONE_NEWNET); + ns_current_ns_fd = ns_id; + } + } + } else + ret = socket(domain, type, protocol); + + return ret; +} + +/* if relative link_nsid matches default netns, + * then return default absolute netns value + * otherwise, return NS_UNKNOWN + */ +ns_id_t ns_id_get_absolute(ns_id_t ns_id_reference, ns_id_t link_nsid) +{ + struct ns *ns; + + ns = ns_lookup(ns_id_reference); + if (!ns) + return NS_UNKNOWN; + + if (ns->relative_default_ns != link_nsid) + return NS_UNKNOWN; + + ns = ns_get_default(); + assert(ns); + return ns->ns_id; +} + +struct ns *ns_get_default(void) +{ + return default_ns; +} |