diff options
Diffstat (limited to 'src/core/netdev.c')
| -rw-r--r-- | src/core/netdev.c | 962 |
1 files changed, 962 insertions, 0 deletions
diff --git a/src/core/netdev.c b/src/core/netdev.c new file mode 100644 index 00000000..e244ed18 --- /dev/null +++ b/src/core/netdev.c @@ -0,0 +1,962 @@ + +/* network device (interface) functions. + * (C) 2023 by sysmocom - s.m.f.c. GmbH <info@sysmocom.de> + * Author: Pau Espin Pedrol <pespin@sysmocom.de> + * + * All Rights Reserved + * + * SPDX-License-Identifier: GPL-2.0+ + * + * This program 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 of the License, or + * (at your option) any later version. + * + * This program 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. + * + */ + +#include "config.h" + +/*! \addtogroup netdev + * @{ + * network device (interface) convenience functions + * + * \file netdev.c + * + * Example lifecycle use of the API: + * + * struct osmo_sockaddr_str osa_str = {}; + * struct osmo_sockaddr osa = {}; + * + * // Allocate object: + * struct osmo_netdev *netdev = osmo_netdev_alloc(parent_talloc_ctx, name); + * OSMO_ASSERT(netdev); + * + * // Configure object (before registration): + * rc = osmo_netdev_set_netns_name(netdev, "some_netns_name_or_null"); + * rc = osmo_netdev_set_ifindex(netdev, if_nametoindex("eth0")); + * + * // Register object: + * rc = osmo_netdev_register(netdev); + * // The network interface is now being monitored and the network interface + * // can be operated (see below) + * + * // Add a local IPv4 address: + * rc = osmo_sockaddr_str_from_str2(&osa_str, "192.168.200.1"); + * rc = osmo_sockaddr_str_to_sockaddr(&osa_str, &osa.u.sas); + * rc = osmo_netdev_add_addr(netdev, &osa, 24); + * + * // Bring network interface up: + * rc = osmo_netdev_ifupdown(netdev, true); + * + * // Add default route (0.0.0.0/0): + * rc = osmo_sockaddr_str_from_str2(&osa_str, "0.0.0.0"); + * rc = osmo_sockaddr_str_to_sockaddr(&osa_str, &osa.u.sas); + * rc = osmo_netdev_add_route(netdev, &osa, 0, NULL); + * + * // Unregister (can be freed directly too): + * rc = osmo_netdev_unregister(netdev); + * // Free the object: + * osmo_netdev_free(netdev); + */ + +#if (!EMBEDDED) + +#include <stdio.h> +#include <stdlib.h> +#include <stdio.h> +#include <fcntl.h> +#include <unistd.h> +#include <errno.h> +#include <ifaddrs.h> +#include <sys/types.h> +#include <sys/time.h> +#include <sys/ioctl.h> +#include <sys/socket.h> +#include <sys/stat.h> +#include <sys/time.h> +#include <net/if.h> +#include <net/route.h> + +#if defined(__linux__) +#include <linux/if_link.h> +#include <linux/rtnetlink.h> +#else +#error "Unknown platform!" +#endif + +#include <osmocom/core/utils.h> +#include <osmocom/core/select.h> +#include <osmocom/core/linuxlist.h> +#include <osmocom/core/logging.h> +#include <osmocom/core/socket.h> +#include <osmocom/core/netns.h> +#include <osmocom/core/netdev.h> + +#if ENABLE_LIBMNL +#include <osmocom/core/mnl.h> +#endif + +#define IFINDEX_UNUSED 0 + +#define LOGNETDEV(netdev, lvl, fmt, args ...) \ + LOGP(DLGLOBAL, lvl, "NETDEV(%s,if=%s/%u,ns=%s): " fmt, \ + (netdev)->name, osmo_netdev_get_dev_name(netdev) ? : "", \ + (netdev)->ifindex, (netdev)->netns_name ? : "", ## args) + +static struct llist_head g_netdev_netns_ctx_list = LLIST_HEAD_INIT(g_netdev_netns_ctx_list); +static struct llist_head g_netdev_list = LLIST_HEAD_INIT(g_netdev_list); + +/* One per netns, shared by all osmo_netdev in a given netns: */ +struct netdev_netns_ctx { + struct llist_head entry; /* entry in g_netdev_netns_ctx_list */ + unsigned int refcount; /* Number of osmo_netdev currently registered on this netns */ + const char *netns_name; /* default netns has empty string "" (never NULL!) */ + int netns_fd; /* FD to the netns with name "netns_name" above */ +#if ENABLE_LIBMNL + struct osmo_mnl *omnl; +#endif +}; + +static struct netdev_netns_ctx *netdev_netns_ctx_alloc(void *ctx, const char *netns_name) +{ + struct netdev_netns_ctx *netns_ctx; + OSMO_ASSERT(netns_name); + + netns_ctx = talloc_zero(ctx, struct netdev_netns_ctx); + if (!netns_ctx) + return NULL; + + netns_ctx->netns_name = talloc_strdup(netns_ctx, netns_name); + netns_ctx->netns_fd = -1; + + llist_add_tail(&netns_ctx->entry, &g_netdev_netns_ctx_list); + return netns_ctx; + +} + +static void netdev_netns_ctx_free(struct netdev_netns_ctx *netns_ctx) +{ + if (!netns_ctx) + return; + + llist_del(&netns_ctx->entry); + +#if ENABLE_LIBMNL + if (netns_ctx->omnl) { + osmo_mnl_destroy(netns_ctx->omnl); + netns_ctx->omnl = NULL; + } +#endif + + if (netns_ctx->netns_fd != -1) { + close(netns_ctx->netns_fd); + netns_ctx->netns_fd = -1; + } + talloc_free(netns_ctx); +} + +#if ENABLE_LIBMNL +static int netdev_netns_ctx_mnl_cb(const struct nlmsghdr *nlh, void *data); +#endif + +static int netdev_netns_ctx_init(struct netdev_netns_ctx *netns_ctx) +{ + struct osmo_netns_switch_state switch_state; + int rc; + + if (netns_ctx->netns_name[0] != '\0') { + LOGP(DLGLOBAL, LOGL_INFO, "Prepare netns: Switch to netns '%s'\n", netns_ctx->netns_name); + netns_ctx->netns_fd = osmo_netns_open_fd(netns_ctx->netns_name); + if (netns_ctx->netns_fd < 0) { + LOGP(DLGLOBAL, LOGL_ERROR, "Prepare netns: Cannot switch to netns '%s': %s (%d)\n", + netns_ctx->netns_name, strerror(errno), errno); + return netns_ctx->netns_fd; + } + + /* temporarily switch to specified namespace to create netlink socket */ + rc = osmo_netns_switch_enter(netns_ctx->netns_fd, &switch_state); + if (rc < 0) { + LOGP(DLGLOBAL, LOGL_ERROR, "Prepare netns: Cannot switch to netns '%s': %s (%d)\n", + netns_ctx->netns_name, strerror(errno), errno); + /* netns_ctx->netns_fd will be freed by future call to netdev_netns_ctx_free() */ + return rc; + } + } + +#if ENABLE_LIBMNL + netns_ctx->omnl = osmo_mnl_init(NULL, NETLINK_ROUTE, RTMGRP_LINK, netdev_netns_ctx_mnl_cb, netns_ctx); + rc = (netns_ctx->omnl ? 0 : -EFAULT); +#else + rc = 0; +#endif + + /* switch back to default namespace */ + if (netns_ctx->netns_name[0] != '\0') { + int rc2 = osmo_netns_switch_exit(&switch_state); + if (rc2 < 0) { + LOGP(DLGLOBAL, LOGL_ERROR, "Prepare netns: Cannot switch back from netns '%s': %s\n", + netns_ctx->netns_name, strerror(errno)); + return rc2; + } + LOGP(DLGLOBAL, LOGL_INFO, "Prepare netns: Back from netns '%s'\n", + netns_ctx->netns_name); + } + return rc; +} + +static struct netdev_netns_ctx *netdev_netns_ctx_find_by_netns_name(const char *netns_name) +{ + struct netdev_netns_ctx *netns_ctx; + + llist_for_each_entry(netns_ctx, &g_netdev_netns_ctx_list, entry) { + if (strcmp(netns_ctx->netns_name, netns_name)) + continue; + return netns_ctx; + } + + return NULL; +} + +static struct netdev_netns_ctx *netdev_netns_ctx_get(const char *netns_name) +{ + struct netdev_netns_ctx *netns_ctx; + int rc; + + OSMO_ASSERT(netns_name); + netns_ctx = netdev_netns_ctx_find_by_netns_name(netns_name); + if (!netns_ctx) { + netns_ctx = netdev_netns_ctx_alloc(NULL, netns_name); + if (!netns_ctx) + return NULL; + rc = netdev_netns_ctx_init(netns_ctx); + if (rc < 0) { + netdev_netns_ctx_free(netns_ctx); + return NULL; + } + } + netns_ctx->refcount++; + return netns_ctx; +} + +static void netdev_netns_ctx_put(struct netdev_netns_ctx *netns_ctx) +{ + OSMO_ASSERT(netns_ctx); + netns_ctx->refcount--; + + if (netns_ctx->refcount == 0) + netdev_netns_ctx_free(netns_ctx); +} + +struct osmo_netdev { + /* entry in g_netdev_list */ + struct llist_head entry; + + /* Pointer to struct shared (refcounted) by all osmo_netdev in the same netns: */ + struct netdev_netns_ctx *netns_ctx; + + /* Name used to identify the osmo_netdev */ + char *name; + + /* ifindex of the network interface (address space is per netns) */ + unsigned int ifindex; + + /* Network interface name. Can change over lifetime of the interface. */ + char *dev_name; + + /* netns name where the netdev interface is created (NULL = default netns) */ + char *netns_name; + + /* API user private data */ + void *priv_data; + + /* Whether the netdev is in operation (managing the netdev interface) */ + bool registered; + + /* Called by netdev each time a new up/down state change is detected. Can be NULL. */ + osmo_netdev_ifupdown_ind_cb_t ifupdown_ind_cb; + + /* Called by netdev each time the registered network interface is renamed by the system. Can be NULL. */ + osmo_netdev_dev_name_chg_cb_t dev_name_chg_cb; + + /* Called by netdev each time the configured MTU changes in registered network interface. Can be NULL. */ + osmo_netdev_mtu_chg_cb_t mtu_chg_cb; + + /* Whether the netdev interface is UP */ + bool if_up; + /* Whether we know the interface updown state (aka if if_up holds information)*/ + bool if_up_known; + + /* The netdev interface MTU size */ + uint32_t if_mtu; + /* Whether we know the interface MTU size (aka if if_mtu holds information)*/ + bool if_mtu_known; +}; + +#define NETDEV_NETNS_ENTER(netdev, switch_state, str_prefix) \ + do { \ + if ((netdev)->netns_name) { \ + LOGNETDEV(netdev, LOGL_DEBUG, str_prefix ": Switch to netns '%s'\n", \ + (netdev)->netns_name); \ + int rc2 = osmo_netns_switch_enter((netdev)->netns_ctx->netns_fd, switch_state); \ + if (rc2 < 0) { \ + LOGNETDEV(netdev, LOGL_ERROR, str_prefix ": Cannot switch to netns '%s': %s (%d)\n", \ + (netdev)->netns_name, strerror(errno), errno); \ + return -EACCES; \ + } \ + } \ + } while (0) + +#define NETDEV_NETNS_EXIT(netdev, switch_state, str_prefix) \ + do { \ + if ((netdev)->netns_name) { \ + int rc2 = osmo_netns_switch_exit(switch_state); \ + if (rc2 < 0) { \ + LOGNETDEV(netdev, LOGL_ERROR, str_prefix ": Cannot switch back from netns '%s': %s\n", \ + (netdev)->netns_name, strerror(errno)); \ + return rc2; \ + } \ + LOGNETDEV(netdev, LOGL_DEBUG, str_prefix ": Back from netns '%s'\n", \ + (netdev)->netns_name); \ + } \ + } while (0) + +#if ENABLE_LIBMNL +/* validate the netlink attributes */ +static int netdev_mnl_data_attr_cb(const struct nlattr *attr, void *data) +{ + const struct nlattr **tb = data; + int type = mnl_attr_get_type(attr); + + if (mnl_attr_type_valid(attr, IFLA_MAX) < 0) + return MNL_CB_OK; + + switch (type) { + case IFLA_ADDRESS: + if (mnl_attr_validate(attr, MNL_TYPE_BINARY) < 0) + return MNL_CB_ERROR; + break; + case IFLA_MTU: + if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) + return MNL_CB_ERROR; + break; + case IFLA_IFNAME: + if (mnl_attr_validate(attr, MNL_TYPE_STRING) < 0) + return MNL_CB_ERROR; + break; + } + tb[type] = attr; + return MNL_CB_OK; +} + +static void netdev_mnl_check_mtu_change(struct osmo_netdev *netdev, uint32_t mtu) +{ + if (netdev->if_mtu_known && netdev->if_mtu == mtu) + return; + + LOGNETDEV(netdev, LOGL_NOTICE, "MTU changed: %u\n", mtu); + if (netdev->mtu_chg_cb) + netdev->mtu_chg_cb(netdev, mtu); + + netdev->if_mtu_known = true; + netdev->if_mtu = mtu; +} + +static void netdev_mnl_check_link_state_change(struct osmo_netdev *netdev, bool if_up) +{ + if (netdev->if_up_known && netdev->if_up == if_up) + return; + + LOGNETDEV(netdev, LOGL_NOTICE, "Physical link state changed: %s\n", + if_up ? "UP" : "DOWN"); + if (netdev->ifupdown_ind_cb) + netdev->ifupdown_ind_cb(netdev, if_up); + + netdev->if_up_known = true; + netdev->if_up = if_up; +} + +static int netdev_mnl_cb(struct osmo_netdev *netdev, struct ifinfomsg *ifm, struct nlattr **tb) +{ + char ifnamebuf[IF_NAMESIZE]; + const char *ifname = NULL; + bool if_running; + + if (tb[IFLA_IFNAME]) { + ifname = mnl_attr_get_str(tb[IFLA_IFNAME]); + LOGNETDEV(netdev, LOGL_DEBUG, "%s(): ifname=%s\n", __func__, ifname); + } else { + /* Try harder to obtain the ifname. This code path should in + * general not be triggered since usually IFLA_IFNAME is there */ + struct osmo_netns_switch_state switch_state; + NETDEV_NETNS_ENTER(netdev, &switch_state, "if_indextoname"); + ifname = if_indextoname(ifm->ifi_index, ifnamebuf); + NETDEV_NETNS_EXIT(netdev, &switch_state, "if_indextoname"); + } + if (ifname) { + /* Update dev_name if it changed: */ + if (strcmp(netdev->dev_name, ifname) != 0) { + if (netdev->dev_name_chg_cb) + netdev->dev_name_chg_cb(netdev, ifname); + osmo_talloc_replace_string(netdev, &netdev->dev_name, ifname); + } + } + + if (tb[IFLA_MTU]) { + uint32_t mtu = mnl_attr_get_u32(tb[IFLA_MTU]); + LOGNETDEV(netdev, LOGL_DEBUG, "%s(): mtu=%u\n", __func__, mtu); + netdev_mnl_check_mtu_change(netdev, mtu); + } + if (tb[IFLA_ADDRESS]) { + uint8_t *hwaddr = mnl_attr_get_payload(tb[IFLA_ADDRESS]); + uint16_t hwaddr_len = mnl_attr_get_payload_len(tb[IFLA_ADDRESS]); + LOGNETDEV(netdev, LOGL_DEBUG, "%s(): hwaddress=%s\n", + __func__, osmo_hexdump(hwaddr, hwaddr_len)); + } + + if_running = !!(ifm->ifi_flags & IFF_RUNNING); + LOGNETDEV(netdev, LOGL_DEBUG, "%s(): up=%u running=%u\n", + __func__, !!(ifm->ifi_flags & IFF_UP), if_running); + netdev_mnl_check_link_state_change(netdev, if_running); + + return MNL_CB_OK; +} + +static int netdev_netns_ctx_mnl_cb(const struct nlmsghdr *nlh, void *data) +{ + struct osmo_mnl *omnl = data; + struct netdev_netns_ctx *netns_ctx = (struct netdev_netns_ctx *)omnl->priv; + struct nlattr *tb[IFLA_MAX+1] = {}; + struct ifinfomsg *ifm = mnl_nlmsg_get_payload(nlh); + struct osmo_netdev *netdev; + + OSMO_ASSERT(omnl); + OSMO_ASSERT(ifm); + + mnl_attr_parse(nlh, sizeof(*ifm), netdev_mnl_data_attr_cb, tb); + + LOGP(DLGLOBAL, LOGL_DEBUG, + "%s(): index=%d type=%d flags=0x%x family=%d\n", __func__, + ifm->ifi_index, ifm->ifi_type, ifm->ifi_flags, ifm->ifi_family); + + if (ifm->ifi_index == IFINDEX_UNUSED) + return MNL_CB_ERROR; + + /* Find the netdev (if any) using key <netns,ifindex>. + * Different users of the API may have its own osmo_netdev object + * tracking potentially same netif, hence we need to iterate the whole list + * and dispatch to all matches: + */ + bool found_any = false; + llist_for_each_entry(netdev, &g_netdev_list, entry) { + if (!netdev->registered) + continue; + if (netdev->ifindex != ifm->ifi_index) + continue; + if (strcmp(netdev->netns_ctx->netns_name, netns_ctx->netns_name)) + continue; + found_any = true; + netdev_mnl_cb(netdev, ifm, &tb[0]); + } + + if (!found_any) { + LOGP(DLGLOBAL, LOGL_DEBUG, "%s(): device with ifindex %u on netns %s not registered\n", __func__, + ifm->ifi_index, netns_ctx->netns_name); + } + return MNL_CB_OK; +} + +/* Trigger an initial dump of the iface to get link information */ +static int netdev_mnl_request_initial_dump(struct osmo_mnl *omnl, unsigned int if_index) +{ + char buf[MNL_SOCKET_BUFFER_SIZE]; + struct nlmsghdr *nlh = mnl_nlmsg_put_header(buf); + struct ifinfomsg *ifm; + + nlh->nlmsg_type = RTM_GETLINK; + nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK; + nlh->nlmsg_seq = time(NULL); + + ifm = mnl_nlmsg_put_extra_header(nlh, sizeof(*ifm)); + ifm->ifi_family = AF_UNSPEC; + ifm->ifi_index = if_index; + + if (mnl_socket_sendto(omnl->mnls, nlh, nlh->nlmsg_len) < 0) { + LOGP(DLGLOBAL, LOGL_ERROR, "mnl_socket_sendto\n"); + return -EIO; + } + + return 0; +} + +static int netdev_mnl_set_ifupdown(struct osmo_mnl *omnl, unsigned int if_index, + const char *dev_name, bool up) +{ + char buf[MNL_SOCKET_BUFFER_SIZE]; + struct nlmsghdr *nlh = mnl_nlmsg_put_header(buf); + struct ifinfomsg *ifm; + unsigned int change = 0; + unsigned int flags = 0; + + if (up) { + change |= IFF_UP; + flags |= IFF_UP; + } else { + change |= IFF_UP; + flags &= ~IFF_UP; + } + + nlh->nlmsg_type = RTM_NEWLINK; + nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK; + nlh->nlmsg_seq = time(NULL); + + ifm = mnl_nlmsg_put_extra_header(nlh, sizeof(*ifm)); + ifm->ifi_family = AF_UNSPEC; + ifm->ifi_change = change; + ifm->ifi_flags = flags; + ifm->ifi_index = if_index; + + if (dev_name) + mnl_attr_put_str(nlh, IFLA_IFNAME, dev_name); + + if (mnl_socket_sendto(omnl->mnls, nlh, nlh->nlmsg_len) < 0) { + LOGP(DLGLOBAL, LOGL_ERROR, "mnl_socket_sendto\n"); + return -EIO; + } + + return 0; +} + +static int netdev_mnl_add_addr(struct osmo_mnl *omnl, unsigned int if_index, const struct osmo_sockaddr *osa, uint8_t prefix) +{ + char buf[MNL_SOCKET_BUFFER_SIZE]; + struct nlmsghdr *nlh = mnl_nlmsg_put_header(buf); + struct ifaddrmsg *ifm; + + nlh->nlmsg_type = RTM_NEWADDR; + nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_REPLACE | NLM_F_ACK; + nlh->nlmsg_seq = time(NULL); + + ifm = mnl_nlmsg_put_extra_header(nlh, sizeof(*ifm)); + ifm->ifa_family = osa->u.sa.sa_family; + ifm->ifa_prefixlen = prefix; + ifm->ifa_flags = IFA_F_PERMANENT; + ifm->ifa_scope = RT_SCOPE_UNIVERSE; + ifm->ifa_index = if_index; + + /* + * The exact meaning of IFA_LOCAL and IFA_ADDRESS depend + * on the address family being used and the device type. + * For broadcast devices (like the interfaces we use), + * for IPv4 we specify both and they are used interchangeably. + * For IPv6, only IFA_ADDRESS needs to be set. + */ + switch (osa->u.sa.sa_family) { + case AF_INET: + mnl_attr_put_u32(nlh, IFA_LOCAL, osa->u.sin.sin_addr.s_addr); + mnl_attr_put_u32(nlh, IFA_ADDRESS, osa->u.sin.sin_addr.s_addr); + break; + case AF_INET6: + mnl_attr_put(nlh, IFA_ADDRESS, sizeof(struct in6_addr), &osa->u.sin6.sin6_addr); + break; + default: + return -EINVAL; + } + + if (mnl_socket_sendto(omnl->mnls, nlh, nlh->nlmsg_len) < 0) { + LOGP(DLGLOBAL, LOGL_ERROR, "mnl_socket_sendto\n"); + return -EIO; + } + + return 0; +} + +static int netdev_mnl_add_route(struct osmo_mnl *omnl, + unsigned int if_index, + const struct osmo_sockaddr *dst_osa, + uint8_t dst_prefix, + const struct osmo_sockaddr *gw_osa) +{ + char buf[MNL_SOCKET_BUFFER_SIZE]; + struct nlmsghdr *nlh = mnl_nlmsg_put_header(buf); + struct rtmsg *rtm; + + nlh->nlmsg_type = RTM_NEWROUTE; + nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_ACK; + nlh->nlmsg_seq = time(NULL); + + rtm = mnl_nlmsg_put_extra_header(nlh, sizeof(*rtm)); + rtm->rtm_family = dst_osa->u.sa.sa_family; + rtm->rtm_dst_len = dst_prefix; + rtm->rtm_src_len = 0; + rtm->rtm_tos = 0; + rtm->rtm_protocol = RTPROT_STATIC; + rtm->rtm_table = RT_TABLE_MAIN; + rtm->rtm_type = RTN_UNICAST; + rtm->rtm_scope = gw_osa ? RT_SCOPE_UNIVERSE : RT_SCOPE_LINK; + rtm->rtm_flags = 0; + + switch (dst_osa->u.sa.sa_family) { + case AF_INET: + mnl_attr_put_u32(nlh, RTA_DST, dst_osa->u.sin.sin_addr.s_addr); + break; + case AF_INET6: + mnl_attr_put(nlh, RTA_DST, sizeof(struct in6_addr), &dst_osa->u.sin6.sin6_addr); + break; + default: + return -EINVAL; + } + + mnl_attr_put_u32(nlh, RTA_OIF, if_index); + + if (gw_osa) { + switch (gw_osa->u.sa.sa_family) { + case AF_INET: + mnl_attr_put_u32(nlh, RTA_GATEWAY, gw_osa->u.sin.sin_addr.s_addr); + break; + case AF_INET6: + mnl_attr_put(nlh, RTA_GATEWAY, sizeof(struct in6_addr), &gw_osa->u.sin6.sin6_addr); + break; + default: + return -EINVAL; + } + } + + if (mnl_socket_sendto(omnl->mnls, nlh, nlh->nlmsg_len) < 0) { + LOGP(DLGLOBAL, LOGL_ERROR, "mnl_socket_sendto\n"); + return -EIO; + } + + return 0; +} +#endif /* if ENABLE_LIBMNL */ + +/*! Allocate a new netdev object. + * \param[in] ctx talloc context to use as a parent when allocating the netdev object + * \param[in] name A name providen to identify the netdev object + * \returns newly allocated netdev object on success; NULL on error + */ +struct osmo_netdev *osmo_netdev_alloc(void *ctx, const char *name) +{ + struct osmo_netdev *netdev; + + netdev = talloc_zero(ctx, struct osmo_netdev); + if (!netdev) + return NULL; + + netdev->name = talloc_strdup(netdev, name); + + llist_add_tail(&netdev->entry, &g_netdev_list); + return netdev; +} + +/*! Free an allocated netdev object. + * \param[in] netdev The netdev object to free + */ +void osmo_netdev_free(struct osmo_netdev *netdev) +{ + if (!netdev) + return; + if (osmo_netdev_is_registered(netdev)) + osmo_netdev_unregister(netdev); + llist_del(&netdev->entry); + talloc_free(netdev); +} + +/*! Start managing the network device referenced by the netdev object. + * \param[in] netdev The netdev object to open + * \returns 0 on success; negative on error + */ +int osmo_netdev_register(struct osmo_netdev *netdev) +{ + char ifnamebuf[IF_NAMESIZE]; + struct osmo_netns_switch_state switch_state; + int rc = 0; + + if (netdev->registered) + return -EALREADY; + + netdev->netns_ctx = netdev_netns_ctx_get(netdev->netns_name ? : ""); + if (!netdev->netns_ctx) + return -EFAULT; + + NETDEV_NETNS_ENTER(netdev, &switch_state, "register"); + + if (!if_indextoname(netdev->ifindex, ifnamebuf)) { + rc = -ENODEV; + goto err_put_exit; + } + osmo_talloc_replace_string(netdev, &netdev->dev_name, ifnamebuf); + +#if ENABLE_LIBMNL + rc = netdev_mnl_request_initial_dump(netdev->netns_ctx->omnl, netdev->ifindex); +#endif + + NETDEV_NETNS_EXIT(netdev, &switch_state, "register"); + + netdev->registered = true; + return rc; + +err_put_exit: + NETDEV_NETNS_EXIT(netdev, &switch_state, "register"); + netdev_netns_ctx_put(netdev->netns_ctx); + return rc; +} + +/*! Unregister the netdev object (stop managing /moniutoring the interface) + * \param[in] netdev The netdev object to close + * \returns 0 on success; negative on error + */ +int osmo_netdev_unregister(struct osmo_netdev *netdev) +{ + if (!netdev->registered) + return -EALREADY; + + netdev->if_up_known = false; + netdev->if_mtu_known = false; + + netdev_netns_ctx_put(netdev->netns_ctx); + netdev->registered = false; + return 0; +} + +/*! Retrieve whether the netdev object is in "registered" state. + * \param[in] netdev The netdev object to check + * \returns true if in state "registered"; false otherwise + */ +bool osmo_netdev_is_registered(struct osmo_netdev *netdev) +{ + return netdev->registered; +} + +/*! Set private user data pointer on the netdev object. + * \param[in] netdev The netdev object where the field is set + */ +void osmo_netdev_set_priv_data(struct osmo_netdev *netdev, void *priv_data) +{ + netdev->priv_data = priv_data; +} + +/*! Get private user data pointer from the netdev object. + * \param[in] netdev The netdev object from where to retrieve the field + * \returns The current value of the priv_data field. + */ +void *osmo_netdev_get_priv_data(struct osmo_netdev *netdev) +{ + return netdev->priv_data; +} + +/*! Set data_ind_cb callback, called when a new packet is received on the network interface. + * \param[in] netdev The netdev object where the field is set + * \param[in] data_ind_cb the user provided function to be called when the link status (UP/DOWN) changes + */ +void osmo_netdev_set_ifupdown_ind_cb(struct osmo_netdev *netdev, osmo_netdev_ifupdown_ind_cb_t ifupdown_ind_cb) +{ + netdev->ifupdown_ind_cb = ifupdown_ind_cb; +} + +/*! Set dev_name_chg_cb callback, called when a change in the network name is detected + * \param[in] netdev The netdev object where the field is set + * \param[in] dev_name_chg_cb the user provided function to be called when a the interface is renamed + */ +void osmo_netdev_set_dev_name_chg_cb(struct osmo_netdev *netdev, osmo_netdev_dev_name_chg_cb_t dev_name_chg_cb) +{ + netdev->dev_name_chg_cb = dev_name_chg_cb; +} + +/*! Set mtu_chg_cb callback, called when a change in the network name is detected + * \param[in] netdev The netdev object where the field is set + * \param[in] mtu_chg_cb the user provided function to be called when the configured MTU at the interface changes + */ +void osmo_netdev_set_mtu_chg_cb(struct osmo_netdev *netdev, osmo_netdev_mtu_chg_cb_t mtu_chg_cb) +{ + netdev->mtu_chg_cb = mtu_chg_cb; +} + +/*! Get name used to identify the netdev object. + * \param[in] netdev The netdev object from where to retrieve the field + * \returns The current value of the name used to identify the netdev object + */ +const char *osmo_netdev_get_name(const struct osmo_netdev *netdev) +{ + return netdev->name; +} + +/*! Set (specify) interface index identifying the network interface to manage + * \param[in] netdev The netdev object where the field is set + * \param[in] ifindex The interface index identifying the interface + * \returns 0 on success; negative on error + * + * The ifindex, together with the netns_name (see + * osmo_netdev_netns_name_set()), form together the key identifiers of a + * network interface to manage. + * This field is used during osmo_netdev_register() time, and hence must be set + * before calling that API, and cannot be changed when the netdev object is in + * "registered" state. + */ +int osmo_netdev_set_ifindex(struct osmo_netdev *netdev, unsigned int ifindex) +{ + if (netdev->registered) + return -EALREADY; + netdev->ifindex = ifindex; + return 0; +} + +/*! Get interface index identifying the interface managed by netdev + * \param[in] netdev The netdev object from where to retrieve the field + * \returns The current value of the configured netdev interface ifindex to use (0 = unset) + */ +unsigned int osmo_netdev_get_ifindex(const struct osmo_netdev *netdev) +{ + return netdev->ifindex; +} + +/*! Set (specify) name of the network namespace where the network interface to manage is located + * \param[in] netdev The netdev object where the field is set + * \param[in] netns_name The network namespace where the network interface is located + * \returns 0 on success; negative on error + * + * The netns_name, together with the ifindex (see + * osmo_netdev_ifindex_set()), form together the key identifiers of a + * network interface to manage. + * This field is used during osmo_netdev_register() time, and hence must be set + * before calling that API, and cannot be changed when the netdev object is in + * "registered" state. + * If left as NULL (default), the management will be done in the current network namespace. + */ +int osmo_netdev_set_netns_name(struct osmo_netdev *netdev, const char *netns_name) +{ + if (netdev->registered) + return -EALREADY; + osmo_talloc_replace_string(netdev, &netdev->netns_name, netns_name); + return 0; +} + +/*! Get name of network namespace used when opening the netdev interface + * \param[in] netdev The netdev object from where to retrieve the field + * \returns The current value of the configured network namespace + */ +const char *osmo_netdev_get_netns_name(const struct osmo_netdev *netdev) +{ + return netdev->netns_name; +} + +/*! Get name used to name the network interface created by the netdev object + * \param[in] netdev The netdev object from where to retrieve the field + * \returns The interface name (or NULL if unknown) + * + * This information is retrieved internally once the netdev object enters the + * "registered" state. Hence, when not registered NULL can be returned. + */ +const char *osmo_netdev_get_dev_name(const struct osmo_netdev *netdev) +{ + return netdev->dev_name; +} + +/*! Bring netdev interface UP or DOWN. + * \param[in] netdev The netdev object managing the netdev interface + * \param[in] ifupdown true to set the interface UP, false to set it DOWN + * \returns 0 on succes; negative on error. + */ +int osmo_netdev_ifupdown(struct osmo_netdev *netdev, bool ifupdown) +{ + struct osmo_netns_switch_state switch_state; + int rc; + + if (!netdev->registered) + return -ENODEV; + + LOGNETDEV(netdev, LOGL_NOTICE, "Bringing dev %s %s\n", + netdev->dev_name, ifupdown ? "UP" : "DOWN"); + + NETDEV_NETNS_ENTER(netdev, &switch_state, "ifupdown"); + +#if ENABLE_LIBMNL + rc = netdev_mnl_set_ifupdown(netdev->netns_ctx->omnl, netdev->ifindex, + netdev->dev_name, ifupdown); +#else + LOGNETDEV(netdev, LOGL_ERROR, "%s: NOT SUPPORTED. Build libosmocore with --enable-libmnl.\n", __func__); + rc = -ENOTSUP; +#endif + + NETDEV_NETNS_EXIT(netdev, &switch_state, "ifupdown"); + + return rc; +} + +/*! Add IP address to netdev interface + * \param[in] netdev The netdev object managing the netdev interface + * \param[in] addr The local address to set on the interface + * \param[in] prefixlen The network prefix of addr + * \returns 0 on succes; negative on error. + */ +int osmo_netdev_add_addr(struct osmo_netdev *netdev, const struct osmo_sockaddr *addr, uint8_t prefixlen) +{ + struct osmo_netns_switch_state switch_state; + char buf[INET6_ADDRSTRLEN]; + int rc; + + if (!netdev->registered) + return -ENODEV; + + LOGNETDEV(netdev, LOGL_NOTICE, "Adding address %s/%u to dev %s\n", + osmo_sockaddr_ntop(&addr->u.sa, buf), prefixlen, netdev->dev_name); + + NETDEV_NETNS_ENTER(netdev, &switch_state, "Add address"); + +#if ENABLE_LIBMNL + rc = netdev_mnl_add_addr(netdev->netns_ctx->omnl, netdev->ifindex, addr, prefixlen); +#else + LOGNETDEV(netdev, LOGL_ERROR, "%s: NOT SUPPORTED. Build libosmocore with --enable-libmnl.\n", __func__); + rc = -ENOTSUP; +#endif + + NETDEV_NETNS_EXIT(netdev, &switch_state, "Add address"); + + return rc; +} + +/*! Add IP route to netdev interface + * \param[in] netdev The netdev object managing the netdev interface + * \param[in] dst_addr The destination address of the route + * \param[in] dst_prefixlen The network prefix of dst_addr + * \param[in] gw_addr The gateway address. Optional, can be NULL. + * \returns 0 on succes; negative on error. + */ +int osmo_netdev_add_route(struct osmo_netdev *netdev, const struct osmo_sockaddr *dst_addr, uint8_t dst_prefixlen, const struct osmo_sockaddr *gw_addr) +{ + struct osmo_netns_switch_state switch_state; + char buf_dst[INET6_ADDRSTRLEN]; + char buf_gw[INET6_ADDRSTRLEN]; + int rc; + + if (!netdev->registered) + return -ENODEV; + + LOGNETDEV(netdev, LOGL_NOTICE, "Adding route %s/%u%s%s dev %s\n", + osmo_sockaddr_ntop(&dst_addr->u.sa, buf_dst), dst_prefixlen, + gw_addr ? " via " : "", + gw_addr ? osmo_sockaddr_ntop(&gw_addr->u.sa, buf_gw) : "", + netdev->dev_name); + + NETDEV_NETNS_ENTER(netdev, &switch_state, "Add route"); + +#if ENABLE_LIBMNL + rc = netdev_mnl_add_route(netdev->netns_ctx->omnl, netdev->ifindex, dst_addr, dst_prefixlen, gw_addr); +#else + LOGNETDEV(netdev, LOGL_ERROR, "%s: NOT SUPPORTED. Build libosmocore with --enable-libmnl.\n", __func__); + rc = -ENOTSUP; +#endif + + NETDEV_NETNS_EXIT(netdev, &switch_state, "Add route"); + + return rc; +} + +#endif /* (!EMBEDDED) */ + +/*! @} */ |