diff options
Diffstat (limited to 'src/iface.c')
| -rw-r--r-- | src/iface.c | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/src/iface.c b/src/iface.c new file mode 100644 index 0000000..428acaa --- /dev/null +++ b/src/iface.c @@ -0,0 +1,173 @@ +/* + * Copyright (c) 2015 Pablo Neira Ayuso <pablo@netfilter.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 (or any + * later) as published by the Free Software Foundation. + */ + +#include <nft.h> + +#include <stdio.h> +#include <net/if.h> +#include <time.h> +#include <errno.h> + +#include <libmnl/libmnl.h> +#include <linux/rtnetlink.h> + +#include <nftables.h> +#include <list.h> +#include <netlink.h> +#include <iface.h> + +static LIST_HEAD(iface_list); +static bool iface_cache_init; + +static int 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_IFNAME: + if (mnl_attr_validate(attr, MNL_TYPE_STRING) < 0) + netlink_abi_error(); + break; + default: + return MNL_CB_OK; + } + tb[type] = attr; + return MNL_CB_OK; +} + +static int data_cb(const struct nlmsghdr *nlh, void *data) +{ + struct nlattr *tb[IFLA_MAX + 1] = {}; + struct ifinfomsg *ifm = mnl_nlmsg_get_payload(nlh); + struct iface *iface; + + iface = xmalloc(sizeof(struct iface)); + iface->ifindex = ifm->ifi_index; + mnl_attr_parse(nlh, sizeof(*ifm), data_attr_cb, tb); + snprintf(iface->name, IFNAMSIZ, "%s", mnl_attr_get_str(tb[IFLA_IFNAME])); + list_add(&iface->list, &iface_list); + + return MNL_CB_OK; +} + +static int iface_mnl_talk(struct mnl_socket *nl, uint32_t portid) +{ + char buf[MNL_SOCKET_BUFFER_SIZE]; + struct nlmsghdr *nlh; + struct rtgenmsg *rt; + bool eintr = false; + uint32_t seq; + int ret; + + nlh = mnl_nlmsg_put_header(buf); + nlh->nlmsg_type = RTM_GETLINK; + nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP; + nlh->nlmsg_seq = seq = time(NULL); + rt = mnl_nlmsg_put_extra_header(nlh, sizeof(struct rtgenmsg)); + rt->rtgen_family = AF_PACKET; + + if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) + return -1; + + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + while (ret > 0) { + ret = mnl_cb_run(buf, ret, seq, portid, data_cb, NULL); + if (ret == 0) + break; + if (ret < 0) { + if (errno != EINTR) + return ret; + + /* process all pending messages before reporting EINTR */ + eintr = true; + } + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + } + + if (eintr) { + ret = -1; + errno = EINTR; + } + + return ret; +} + +void iface_cache_update(void) +{ + struct mnl_socket *nl; + uint32_t portid; + int ret; + + nl = mnl_socket_open(NETLINK_ROUTE); + if (nl == NULL) + netlink_init_error(); + + if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) + netlink_init_error(); + + portid = mnl_socket_get_portid(nl); + + do { + ret = iface_mnl_talk(nl, portid); + } while (ret < 0 && errno == EINTR); + + if (ret == -1) + netlink_init_error(); + + mnl_socket_close(nl); + + iface_cache_init = true; +} + +void iface_cache_release(void) +{ + struct iface *iface, *next; + + if (!iface_cache_init) + return; + + list_for_each_entry_safe(iface, next, &iface_list, list) { + list_del(&iface->list); + free(iface); + } + iface_cache_init = false; +} + +unsigned int nft_if_nametoindex(const char *name) +{ + struct iface *iface; + + if (!iface_cache_init) + iface_cache_update(); + + list_for_each_entry(iface, &iface_list, list) { + if (strncmp(name, iface->name, IFNAMSIZ) == 0) + return iface->ifindex; + } + return 0; +} + +char *nft_if_indextoname(unsigned int ifindex, char *name) +{ + struct iface *iface; + + if (!iface_cache_init) + iface_cache_update(); + + list_for_each_entry(iface, &iface_list, list) { + if (iface->ifindex == ifindex) { + snprintf(name, IFNAMSIZ, "%s", iface->name); + return name; + } + } + return NULL; +} |