ll_map: add name and index hash
Make ll_ functions faster by having a name hash, and allow
for deletion. Also, allow them to work without calling ll_init_map.
diff --git a/include/hlist.h b/include/hlist.h
new file mode 100644
index 0000000..4e8de9e
--- /dev/null
+++ b/include/hlist.h
@@ -0,0 +1,56 @@
+#ifndef __HLIST_H__
+#define __HLIST_H__ 1
+/* Hash list stuff from kernel */
+
+#include <stddef.h>
+
+#define container_of(ptr, type, member) ({ \
+ const typeof( ((type *)0)->member ) *__mptr = (ptr); \
+ (type *)( (char *)__mptr - offsetof(type,member) );})
+
+struct hlist_head {
+ struct hlist_node *first;
+};
+
+struct hlist_node {
+ struct hlist_node *next, **pprev;
+};
+
+static inline void hlist_del(struct hlist_node *n)
+{
+ struct hlist_node *next = n->next;
+ struct hlist_node **pprev = n->pprev;
+ *pprev = next;
+ if (next)
+ next->pprev = pprev;
+}
+
+static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h)
+{
+ struct hlist_node *first = h->first;
+ n->next = first;
+ if (first)
+ first->pprev = &n->next;
+ h->first = n;
+ n->pprev = &h->first;
+}
+
+#define hlist_for_each(pos, head) \
+ for (pos = (head)->first; pos ; pos = pos->next)
+
+
+#define hlist_for_each_safe(pos, n, head) \
+ for (pos = (head)->first; pos && ({ n = pos->next; 1; }); \
+ pos = n)
+
+#define hlist_entry_safe(ptr, type, member) \
+ ({ typeof(ptr) ____ptr = (ptr); \
+ ____ptr ? hlist_entry(____ptr, type, member) : NULL; \
+ })
+
+#define hlist_for_each_entry(pos, head, member) \
+ for (pos = hlist_entry_safe((head)->first, typeof(*(pos)), member);\
+ pos; \
+ pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member))
+
+#endif /* __HLIST_H__ */
diff --git a/include/ll_map.h b/include/ll_map.h
index c4d5c6d..f1dda39 100644
--- a/include/ll_map.h
+++ b/include/ll_map.h
@@ -3,7 +3,8 @@
extern int ll_remember_index(const struct sockaddr_nl *who,
struct nlmsghdr *n, void *arg);
-extern int ll_init_map(struct rtnl_handle *rth);
+
+extern void ll_init_map(struct rtnl_handle *rth);
extern unsigned ll_name_to_index(const char *name);
extern const char *ll_index_to_name(unsigned idx);
extern const char *ll_idx_n2a(unsigned idx, char *buf);
diff --git a/lib/ll_map.c b/lib/ll_map.c
index e9ae129..fd7db55 100644
--- a/lib/ll_map.c
+++ b/lib/ll_map.c
@@ -22,10 +22,11 @@
#include "libnetlink.h"
#include "ll_map.h"
+#include "hlist.h"
-struct ll_cache
-{
- struct ll_cache *idx_next;
+struct ll_cache {
+ struct hlist_node idx_hash;
+ struct hlist_node name_hash;
unsigned flags;
int index;
unsigned short type;
@@ -33,49 +34,107 @@
};
#define IDXMAP_SIZE 1024
-static struct ll_cache *idx_head[IDXMAP_SIZE];
+static struct hlist_head idx_head[IDXMAP_SIZE];
+static struct hlist_head name_head[IDXMAP_SIZE];
-static inline struct ll_cache *idxhead(int idx)
+static struct ll_cache *ll_get_by_index(unsigned index)
{
- return idx_head[idx & (IDXMAP_SIZE - 1)];
+ 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;
+}
+
+static 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(const struct sockaddr_nl *who,
struct nlmsghdr *n, void *arg)
{
- int h;
+ unsigned int h;
+ const char *ifname;
struct ifinfomsg *ifi = NLMSG_DATA(n);
- struct ll_cache *im, **imp;
+ struct ll_cache *im;
struct rtattr *tb[IFLA_MAX+1];
- if (n->nlmsg_type != RTM_NEWLINK)
+ if (n->nlmsg_type != RTM_NEWLINK && n->nlmsg_type != RTM_DELLINK)
return 0;
if (n->nlmsg_len < NLMSG_LENGTH(sizeof(ifi)))
return -1;
- memset(tb, 0, sizeof(tb));
- parse_rtattr(tb, IFLA_MAX, IFLA_RTA(ifi), IFLA_PAYLOAD(n));
- if (tb[IFLA_IFNAME] == NULL)
+ 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;
-
- h = ifi->ifi_index & (IDXMAP_SIZE - 1);
- for (imp = &idx_head[h]; (im=*imp)!=NULL; imp = &im->idx_next)
- if (im->index == ifi->ifi_index)
- break;
-
- if (im == NULL) {
- im = malloc(sizeof(*im));
- if (im == NULL)
- return 0;
- im->idx_next = *imp;
- im->index = ifi->ifi_index;
- *imp = im;
}
+ memset(tb, 0, sizeof(tb));
+ 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));
+ if (im == NULL)
+ return 0;
+ im->index = ifi->ifi_index;
+ strcpy(im->name, ifname);
im->type = ifi->ifi_type;
im->flags = ifi->ifi_flags;
- strcpy(im->name, RTA_DATA(tb[IFLA_IFNAME]));
+
+ 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;
}
@@ -86,15 +145,16 @@
if (idx == 0)
return "*";
- for (im = idxhead(idx); im; im = im->idx_next)
- if (im->index == idx)
- return im->name;
+ im = ll_get_by_index(idx);
+ if (im)
+ return im->name;
- snprintf(buf, IFNAMSIZ, "if%d", idx);
+ if (if_indextoname(idx, buf) == NULL)
+ snprintf(buf, IFNAMSIZ, "if%d", idx);
+
return buf;
}
-
const char *ll_index_to_name(unsigned idx)
{
static char nbuf[IFNAMSIZ];
@@ -108,10 +168,9 @@
if (idx == 0)
return -1;
- for (im = idxhead(idx); im; im = im->idx_next)
- if (im->index == idx)
- return im->type;
- return -1;
+
+ im = ll_get_by_index(idx);
+ return im ? im->type : -1;
}
unsigned ll_index_to_flags(unsigned idx)
@@ -121,35 +180,21 @@
if (idx == 0)
return 0;
- for (im = idxhead(idx); im; im = im->idx_next)
- if (im->index == idx)
- return im->flags;
- return 0;
+ im = ll_get_by_index(idx);
+ return im ? im->flags : -1;
}
unsigned ll_name_to_index(const char *name)
{
- static char ncache[IFNAMSIZ];
- static int icache;
- struct ll_cache *im;
- int i;
+ const struct ll_cache *im;
unsigned idx;
if (name == NULL)
return 0;
- if (icache && strcmp(name, ncache) == 0)
- return icache;
-
- for (i=0; i<IDXMAP_SIZE; i++) {
- for (im = idx_head[i]; im; im = im->idx_next) {
- if (strcmp(im->name, name) == 0) {
- icache = im->index;
- strcpy(ncache, name);
- return im->index;
- }
- }
- }
+ im = ll_get_by_name(name);
+ if (im)
+ return im->index;
idx = if_nametoindex(name);
if (idx == 0)
@@ -157,12 +202,12 @@
return idx;
}
-int ll_init_map(struct rtnl_handle *rth)
+void ll_init_map(struct rtnl_handle *rth)
{
static int initialized;
if (initialized)
- return 0;
+ return;
if (rtnl_wilddump_request(rth, AF_UNSPEC, RTM_GETLINK) < 0) {
perror("Cannot send dump request");
@@ -175,6 +220,4 @@
}
initialized = 1;
-
- return 0;
}
