/* * netsniff-ng - the packet sniffing beast * Copyright 2011 Daniel Borkmann. * Subject to the GPL, version 2. */ #define _GNU_SOURCE #include #include #include #include #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); } 'q' value=''/>

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