all: import netsniff-ng 0.5.8-rc0 source

We decided to get rid of the old Git history and start a new one for
several reasons:

 *) Allow / enforce only high-quality commits (which was not the case
    for many commits in the history), have a policy that is more close
    to the one from the Linux kernel. With high quality commits, we
    mean code that is logically split into commits and commit messages
    that are signed-off and have a proper subject and message body.
    We do not allow automatic Github merges anymore, since they are
    total bullshit. However, we will either cherry-pick your patches
    or pull them manually.

 *) The old archive was about ~27MB for no particular good reason.
    This basically derived from the bad decision that also some PDF
    files where stored there. From this moment onwards, no binary
    objects are allowed to be stored in this repository anymore.

The old archive is not wiped away from the Internet. You will still
be able to find it, e.g. on git.cryptoism.org etc.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>

1 files changed, 180 insertions, 0 deletions

diff --git a/cpusched.c b/cpusched.c
new file mode 100644
index 0000000..13ed9a7
--- /dev/null
+++ b/cpusched.c
@@ -0,0 +1,180 @@
+/*
+ * netsniff-ng - the packet sniffing beast
+ * Copyright 2011 Daniel Borkmann.
+ * Subject to the GPL, version 2.
+ */
+
+#define _GNU_SOURCE
+#include <search.h>
+#include <limits.h>
+#include <errno.h>
+#include <string.h>
+
+#include "locking.h"
+#include "cpusched.h"
+#include "xmalloc.h"
+#include "hash.h"
+
+struct map_entry {
+	int fd;
+	unsigned int cpu;
+	struct map_entry *next;
+};
+
+static struct hash_table mapper;
+
+static unsigned int *cpu_assigned = NULL;
+
+static unsigned int cpu_len = 0;
+
+static struct rwlock map_lock;
+
+void init_cpusched(unsigned int cpus)
+{
+	rwlock_init(&map_lock);
+	rwlock_wr_lock(&map_lock);
+
+	cpu_len = cpus;
+	cpu_assigned = xzmalloc(cpus * sizeof(*cpu_assigned));
+
+	memset(&mapper, 0, sizeof(mapper));
+	init_hash(&mapper);
+
+	rwlock_unlock(&map_lock);
+}
+
+static int get_appropriate_cpu(void)
+{
+	int i, cpu = 0;
+	int work = INT_MAX;
+
+	for (i = 0; i < cpu_len; ++i) {
+		if (cpu_assigned[i] < work) {
+			work = cpu_assigned[i];
+			cpu = i;
+		}
+	}
+
+	return cpu;
+}
+
+unsigned int socket_to_cpu(int fd)
+{
+	int cpu = 0;
+	struct map_entry *entry;
+
+	errno = 0;
+
+	rwlock_rd_lock(&map_lock);
+
+	entry = lookup_hash(fd, &mapper);
+	while (entry && fd != entry->fd)
+		entry = entry->next;
+	if (entry && fd == entry->fd)
+		cpu = entry->cpu;
+	else
+		errno = ENOENT;
+
+	rwlock_unlock(&map_lock);
+
+	return cpu;
+}
+
+unsigned int register_socket(int fd)
+{
+	void **pos;
+	struct map_entry *entry;
+
+	rwlock_wr_lock(&map_lock);
+
+	entry = xzmalloc(sizeof(*entry));
+	entry->fd = fd;
+	entry->cpu = get_appropriate_cpu();
+
+	cpu_assigned[entry->cpu]++;
+
+	pos = insert_hash(entry->fd, entry, &mapper);
+	if (pos) {
+		entry->next = (*pos);
+		(*pos) = entry;
+	}
+
+	rwlock_unlock(&map_lock);
+
+	return entry->cpu;
+}
+
+static struct map_entry *socket_to_map_entry(int fd)
+{
+	struct map_entry *entry, *ret = NULL;
+
+	errno = 0;
+
+	rwlock_rd_lock(&map_lock);
+
+	entry = lookup_hash(fd, &mapper);
+	while (entry && fd != entry->fd)
+		entry = entry->next;
+	if (entry && fd == entry->fd)
+		ret = entry;
+	else
+		errno = ENOENT;
+
+	rwlock_unlock(&map_lock);
+
+	return ret;
+}
+
+void unregister_socket(int fd)
+{
+	struct map_entry *pos;
+	struct map_entry *entry = socket_to_map_entry(fd);
+
+	if (!entry == 0 && errno == ENOENT)
+		return;
+
+	rwlock_wr_lock(&map_lock);
+
+	cpu_assigned[entry->cpu]--;
+
+	pos = remove_hash(entry->fd, entry, entry->next, &mapper);
+	while (pos && pos->next && pos->next != entry)
+		pos = pos->next;
+	if (pos && pos->next && pos->next == entry)
+		pos->next = entry->next;
+
+	entry->next = NULL;
+	xfree(entry);
+
+	rwlock_unlock(&map_lock);
+}
+
+static int cleanup_batch(void *ptr)
+{
+	struct map_entry *next;
+	struct map_entry *e = ptr;
+
+	if (!e)
+		return 0;
+	while ((next = e->next)) {
+		e->next = NULL;
+		xfree(e);
+		e = next;
+	}
+
+	xfree(e);
+	return 0;
+}
+
+void destroy_cpusched(void)
+{
+	rwlock_wr_lock(&map_lock);
+
+	xfree(cpu_assigned);
+	cpu_len = 0;
+	for_each_hash(&mapper, cleanup_batch);
+	free_hash(&mapper);
+
+	rwlock_unlock(&map_lock);
+	rwlock_destroy(&map_lock);
+}