/* * netsniff-ng - the packet sniffing beast * Copyright 2009, 2010 Daniel Borkmann. * Subject to the GPL, version 2. */ #include #include #include #include #include #include #include #include #include #include "xmalloc.h" #include "die.h" #include "ring_rx.h" #include "built_in.h" void destroy_rx_ring(int sock, struct ring *ring) { int ret; munmap(ring->mm_space, ring->mm_len); ring->mm_len = 0; fmemset(&ring->layout, 0, sizeof(ring->layout)); ret = setsockopt(sock, SOL_PACKET, PACKET_RX_RING, &ring->layout, sizeof(ring->layout)); if (unlikely(ret)) panic("Cannot destroy the RX_RING: %s!\n", strerror(errno)); xfree(ring->frames); } void setup_rx_ring_layout(int sock, struct ring *ring, unsigned int size, int jumbo_support) { fmemset(&ring->layout, 0, sizeof(ring->layout)); ring->layout.tp_block_size = (jumbo_support ? getpagesize() << 4 : getpagesize() << 2); ring->layout.tp_frame_size = (jumbo_support ? TPACKET_ALIGNMENT << 12 : TPACKET_ALIGNMENT << 7); ring->layout.tp_block_nr = size / ring->layout.tp_block_size; ring->layout.tp_frame_nr = ring->layout.tp_block_size / ring->layout.tp_frame_size * ring->layout.tp_block_nr; bug_on(ring->layout.tp_block_size < ring->layout.tp_frame_size); bug_on((ring->layout.tp_block_size % ring->layout.tp_frame_size) != 0); bug_on((ring->layout.tp_block_size % getpagesize()) != 0); } void create_rx_ring(int sock, struct ring *ring, int verbose) { int ret; set_sockopt_tpacket(sock); retry: ret = setsockopt(sock, SOL_PACKET, PACKET_RX_RING, &ring->layout, sizeof(ring->layout)); if (errno == ENOMEM && ring->layout.tp_block_nr > 1) { ring->layout.tp_block_nr >>= 1; ring->layout.tp_frame_nr = ring->layout.tp_block_size / ring->layout.tp_frame_size * ring->layout.tp_block_nr; goto retry; } if (ret < 0) panic("Cannot allocate RX_RING!\n"); ring->mm_len = ring->layout.tp_block_size * ring->layout.tp_block_nr; if (verbose) { printf("RX: %.2Lf MiB, %u Frames, each %u Byte allocated\n", (long double) ring->mm_len / (1 << 20), ring->layout.tp_frame_nr, ring->layout.tp_frame_size); } } void mmap_rx_ring(int sock, struct ring *ring) { ring->mm_space = mmap(0, ring->mm_len, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_LOCKED | MAP_POPULATE, sock, 0); if (ring->mm_space == MAP_FAILED) { destroy_rx_ring(sock, ring); panic("Cannot mmap RX_RING!\n"); } } void alloc_rx_ring_frames(struct ring *ring) { int i; size_t len = ring->layout.tp_frame_nr * sizeof(*ring->frames); ring->frames = xmalloc_aligned(len, CO_CACHE_LINE_SIZE); fmemset(ring->frames, 0, len); for (i = 0; i < ring->layout.tp_frame_nr; ++i) { ring->frames[i].iov_len = ring->layout.tp_frame_size; ring->frames[i].iov_base = ring->mm_space + (i * ring->layout.tp_frame_size); } } void bind_rx_ring(int sock, struct ring *ring, int ifindex) { int ret; /* * The RX_RING registers itself to the networking stack with * dev_add_pack(), so we have one single RX_RING for all devs * otherwise you'll get the packet twice. */ fmemset(&ring->s_ll, 0, sizeof(ring->s_ll)); ring->s_ll.sll_family = AF_PACKET; ring->s_ll.sll_protocol = htons(ETH_P_ALL); ring->s_ll.sll_ifindex = ifindex; ring->s_ll.sll_hatype = 0; ring->s_ll.sll_halen = 0; ring->s_ll.sll_pkttype = 0; ret = bind(sock, (struct sockaddr *) &ring->s_ll, sizeof(ring->s_ll)); if (ret < 0) { destroy_rx_ring(sock, ring); panic("Cannot bind RX_RING!\n"); } } s='content'>
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