+/*
+ * ll_map.c
+ *
+ * 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.
+ *
+ * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <string.h>
+#include <net/if.h>
+
+#include "libnetlink.h"
+#include "ll_map.h"
+#include "list.h"
+
+struct ll_cache {
+ struct hlist_node idx_hash;
+ struct hlist_node name_hash;
+ unsigned flags;
+ unsigned index;
+ unsigned short type;
+ char name[];
+};
+
+#define IDXMAP_SIZE 1024
+static struct hlist_head idx_head[IDXMAP_SIZE];
+static struct hlist_head name_head[IDXMAP_SIZE];
+
+static struct ll_cache *ll_get_by_index(unsigned index)
+{
+ struct hlist_node *n;
+ unsigned h = index & (IDXMAP_SIZE - 1);
+
+ hlist_for_each(n, &idx_head[h]) {
+ struct ll_cache *im
+ = container_of(n, struct ll_cache, idx_hash);
+ if (im->index == index)
+ return im;
+ }
+
+ return NULL;
+}
+
+unsigned namehash(const char *str)
+{
+ unsigned hash = 5381;
+
+ while (*str)
+ hash = ((hash << 5) + hash) + *str++; /* hash * 33 + c */
+
+ return hash;
+}
+
+static struct ll_cache *ll_get_by_name(const char *name)
+{
+ struct hlist_node *n;
+ unsigned h = namehash(name) & (IDXMAP_SIZE - 1);
+
+ hlist_for_each(n, &name_head[h]) {
+ struct ll_cache *im
+ = container_of(n, struct ll_cache, name_hash);
+
+ if (strncmp(im->name, name, IFNAMSIZ) == 0)
+ return im;
+ }
+
+ return NULL;
+}
+
+int ll_remember_index(struct nlmsghdr *n, void *arg)
+{
+ unsigned int h;
+ const char *ifname;
+ struct ifinfomsg *ifi = NLMSG_DATA(n);
+ struct ll_cache *im;
+ struct rtattr *tb[IFLA_MAX+1];
+
+ if (n->nlmsg_type != RTM_NEWLINK && n->nlmsg_type != RTM_DELLINK)
+ return 0;
+
+ if (n->nlmsg_len < NLMSG_LENGTH(sizeof(*ifi)))
+ return -1;
+
+ im = ll_get_by_index(ifi->ifi_index);
+ if (n->nlmsg_type == RTM_DELLINK) {
+ if (im) {
+ hlist_del(&im->name_hash);
+ hlist_del(&im->idx_hash);
+ free(im);
+ }
+ return 0;
+ }
+
+ parse_rtattr(tb, IFLA_MAX, IFLA_RTA(ifi), IFLA_PAYLOAD(n));
+ ifname = rta_getattr_str(tb[IFLA_IFNAME]);
+ if (ifname == NULL)
+ return 0;
+
+ if (im) {
+ /* change to existing entry */
+ if (strcmp(im->name, ifname) != 0) {
+ hlist_del(&im->name_hash);
+ h = namehash(ifname) & (IDXMAP_SIZE - 1);
+ hlist_add_head(&im->name_hash, &name_head[h]);
+ }
+
+ im->flags = ifi->ifi_flags;
+ return 0;
+ }
+
+ im = malloc(sizeof(*im) + strlen(ifname) + 1);
+ if (im == NULL)
+ return 0;
+ im->index = ifi->ifi_index;
+ strcpy(im->name, ifname);
+ im->type = ifi->ifi_type;
+ im->flags = ifi->ifi_flags;
+
+ h = ifi->ifi_index & (IDXMAP_SIZE - 1);
+ hlist_add_head(&im->idx_hash, &idx_head[h]);
+
+ h = namehash(ifname) & (IDXMAP_SIZE - 1);
+ hlist_add_head(&im->name_hash, &name_head[h]);
+
+ return 0;
+}
+
+const char *ll_idx_n2a(unsigned int idx)
+{
+ static char buf[IFNAMSIZ];
+
+ snprintf(buf, sizeof(buf), "if%u", idx);
+ return buf;
+}
+
+static unsigned int ll_idx_a2n(const char *name)
+{
+ unsigned int idx;
+
+ if (sscanf(name, "if%u", &idx) != 1)
+ return 0;
+ return idx;
+}
+
+static int ll_link_get(const char *name, int index)
+{
+ struct {
+ struct nlmsghdr n;
+ struct ifinfomsg ifm;
+ char buf[1024];
+ } req = {
+ .n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
+ .n.nlmsg_flags = NLM_F_REQUEST,
+ .n.nlmsg_type = RTM_GETLINK,
+ .ifm.ifi_index = index,
+ };
+ __u32 filt_mask = RTEXT_FILTER_VF | RTEXT_FILTER_SKIP_STATS;
+ struct rtnl_handle rth = {};
+ struct nlmsghdr *answer;
+ int rc = 0;
+
+ if (rtnl_open(&rth, 0) < 0)
+ return 0;
+
+ addattr32(&req.n, sizeof(req), IFLA_EXT_MASK, filt_mask);
+ if (name)
+ addattr_l(&req.n, sizeof(req), IFLA_IFNAME, name,
+ strlen(name) + 1);
+
+ if (rtnl_talk(&rth, &req.n, &answer) < 0)
+ goto out;
+
+ /* add entry to cache */
+ rc = ll_remember_index(answer, NULL);
+ if (!rc) {
+ struct ifinfomsg *ifm = NLMSG_DATA(answer);
+
+ rc = ifm->ifi_index;
+ }
+
+ free(answer);
+out:
+ rtnl_close(&rth);
+ return rc;
+}
+
+const char *ll_index_to_name(unsigned int idx)
+{
+ static char buf[IFNAMSIZ];
+ const struct ll_cache *im;
+
+ if (idx == 0)
+ return "*";
+
+ im = ll_get_by_index(idx);
+ if (im)
+ return im->name;
+
+ if (ll_link_get(NULL, idx) == idx) {
+ im = ll_get_by_index(idx);
+ if (im)
+ return im->name;
+ }
+
+ if (if_indextoname(idx, buf) == NULL)
+ snprintf(buf, IFNAMSIZ, "if%u", idx);
+
+ return buf;
+}
+
+int ll_index_to_type(unsigned idx)
+{
+ const struct ll_cache *im;
+
+ if (idx == 0)
+ return -1;
+
+ im = ll_get_by_index(idx);
+ return im ? im->type : -1;
+}
+
+int ll_index_to_flags(unsigned idx)
+{
+ const struct ll_cache *im;
+
+ if (idx == 0)
+ return 0;
+
+ im = ll_get_by_index(idx);
+ return im ? im->flags : -1;
+}
+
+unsigned ll_name_to_index(const char *name)
+{
+ const struct ll_cache *im;
+ unsigned idx;
+
+ if (name == NULL)
+ return 0;
+
+ im = ll_get_by_name(name);
+ if (im)
+ return im->index;
+
+ idx = ll_link_get(name, 0);
+ if (idx == 0)
+ idx = if_nametoindex(name);
+ if (idx == 0)
+ idx = ll_idx_a2n(name);
+ return idx;
+}
+
+void ll_drop_by_index(unsigned index)
+{
+ struct ll_cache *im;
+
+ im = ll_get_by_index(index);
+ if (!im)
+ return;
+
+ hlist_del(&im->idx_hash);
+ hlist_del(&im->name_hash);
+
+ free(im);
+}
+
+void ll_init_map(struct rtnl_handle *rth)
+{
+ static int initialized;
+
+ if (initialized)
+ return;
+
+ if (rtnl_linkdump_req(rth, AF_UNSPEC) < 0) {
+ perror("Cannot send dump request");
+ exit(1);
+ }
+
+ if (rtnl_dump_filter(rth, ll_remember_index, NULL) < 0) {
+ fprintf(stderr, "Dump terminated\n");
+ exit(1);
+ }
+
+ initialized = 1;
+}
projects / mirror_iproute2.git / blobdiff