1 /* 2 * test/set flag bits stored in conntrack extension area. 3 * 4 * (C) 2013 Astaro GmbH & Co KG 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 */ 10 11 #include <linux/export.h> 12 #include <linux/types.h> 13 14 #include <net/netfilter/nf_conntrack_ecache.h> 15 #include <net/netfilter/nf_conntrack_labels.h> 16 17 static spinlock_t nf_connlabels_lock; 18 19 int nf_connlabel_set(struct nf_conn *ct, u16 bit) 20 { 21 struct nf_conn_labels *labels = nf_ct_labels_find(ct); 22 23 if (!labels || BIT_WORD(bit) >= labels->words) 24 return -ENOSPC; 25 26 if (test_bit(bit, labels->bits)) 27 return 0; 28 29 if (!test_and_set_bit(bit, labels->bits)) 30 nf_conntrack_event_cache(IPCT_LABEL, ct); 31 32 return 0; 33 } 34 EXPORT_SYMBOL_GPL(nf_connlabel_set); 35 36 static int replace_u32(u32 *address, u32 mask, u32 new) 37 { 38 u32 old, tmp; 39 40 do { 41 old = *address; 42 tmp = (old & mask) ^ new; 43 if (old == tmp) 44 return 0; 45 } while (cmpxchg(address, old, tmp) != old); 46 47 return 1; 48 } 49 50 int nf_connlabels_replace(struct nf_conn *ct, 51 const u32 *data, 52 const u32 *mask, unsigned int words32) 53 { 54 struct nf_conn_labels *labels; 55 unsigned int size, i; 56 int changed = 0; 57 u32 *dst; 58 59 labels = nf_ct_labels_find(ct); 60 if (!labels) 61 return -ENOSPC; 62 63 size = labels->words * sizeof(long); 64 if (size < (words32 * sizeof(u32))) 65 words32 = size / sizeof(u32); 66 67 dst = (u32 *) labels->bits; 68 for (i = 0; i < words32; i++) 69 changed |= replace_u32(&dst[i], mask ? ~mask[i] : 0, data[i]); 70 71 size /= sizeof(u32); 72 for (i = words32; i < size; i++) /* pad */ 73 replace_u32(&dst[i], 0, 0); 74 75 if (changed) 76 nf_conntrack_event_cache(IPCT_LABEL, ct); 77 return 0; 78 } 79 EXPORT_SYMBOL_GPL(nf_connlabels_replace); 80 81 int nf_connlabels_get(struct net *net, unsigned int bits) 82 { 83 size_t words; 84 85 words = BIT_WORD(bits) + 1; 86 if (words > NF_CT_LABELS_MAX_SIZE / sizeof(long)) 87 return -ERANGE; 88 89 spin_lock(&nf_connlabels_lock); 90 net->ct.labels_used++; 91 if (words > net->ct.label_words) 92 net->ct.label_words = words; 93 spin_unlock(&nf_connlabels_lock); 94 95 return 0; 96 } 97 EXPORT_SYMBOL_GPL(nf_connlabels_get); 98 99 void nf_connlabels_put(struct net *net) 100 { 101 spin_lock(&nf_connlabels_lock); 102 net->ct.labels_used--; 103 if (net->ct.labels_used == 0) 104 net->ct.label_words = 0; 105 spin_unlock(&nf_connlabels_lock); 106 } 107 EXPORT_SYMBOL_GPL(nf_connlabels_put); 108 109 static struct nf_ct_ext_type labels_extend __read_mostly = { 110 .len = sizeof(struct nf_conn_labels), 111 .align = __alignof__(struct nf_conn_labels), 112 .id = NF_CT_EXT_LABELS, 113 }; 114 115 int nf_conntrack_labels_init(void) 116 { 117 BUILD_BUG_ON(NF_CT_LABELS_MAX_SIZE / sizeof(long) >= U8_MAX); 118 119 spin_lock_init(&nf_connlabels_lock); 120 return nf_ct_extend_register(&labels_extend); 121 } 122 123 void nf_conntrack_labels_fini(void) 124 { 125 nf_ct_extend_unregister(&labels_extend); 126 } 127