1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * test/set flag bits stored in conntrack extension area. 4 * 5 * (C) 2013 Astaro GmbH & Co KG 6 */ 7 8 #include <linux/export.h> 9 #include <linux/types.h> 10 11 #include <net/netfilter/nf_conntrack_ecache.h> 12 #include <net/netfilter/nf_conntrack_labels.h> 13 14 static DEFINE_SPINLOCK(nf_connlabels_lock); 15 16 static int replace_u32(u32 *address, u32 mask, u32 new) 17 { 18 u32 old, tmp; 19 20 do { 21 old = *address; 22 tmp = (old & mask) ^ new; 23 if (old == tmp) 24 return 0; 25 } while (cmpxchg(address, old, tmp) != old); 26 27 return 1; 28 } 29 30 int nf_connlabels_replace(struct nf_conn *ct, 31 const u32 *data, 32 const u32 *mask, unsigned int words32) 33 { 34 struct nf_conn_labels *labels; 35 unsigned int size, i; 36 int changed = 0; 37 u32 *dst; 38 39 labels = nf_ct_labels_find(ct); 40 if (!labels) 41 return -ENOSPC; 42 43 size = sizeof(labels->bits); 44 if (size < (words32 * sizeof(u32))) 45 words32 = size / sizeof(u32); 46 47 dst = (u32 *) labels->bits; 48 for (i = 0; i < words32; i++) 49 changed |= replace_u32(&dst[i], mask ? ~mask[i] : 0, data[i]); 50 51 size /= sizeof(u32); 52 for (i = words32; i < size; i++) /* pad */ 53 replace_u32(&dst[i], 0, 0); 54 55 if (changed) 56 nf_conntrack_event_cache(IPCT_LABEL, ct); 57 return 0; 58 } 59 EXPORT_SYMBOL_GPL(nf_connlabels_replace); 60 61 int nf_connlabels_get(struct net *net, unsigned int bits) 62 { 63 if (BIT_WORD(bits) >= NF_CT_LABELS_MAX_SIZE / sizeof(long)) 64 return -ERANGE; 65 66 spin_lock(&nf_connlabels_lock); 67 net->ct.labels_used++; 68 spin_unlock(&nf_connlabels_lock); 69 70 BUILD_BUG_ON(NF_CT_LABELS_MAX_SIZE / sizeof(long) >= U8_MAX); 71 72 return 0; 73 } 74 EXPORT_SYMBOL_GPL(nf_connlabels_get); 75 76 void nf_connlabels_put(struct net *net) 77 { 78 spin_lock(&nf_connlabels_lock); 79 net->ct.labels_used--; 80 spin_unlock(&nf_connlabels_lock); 81 } 82 EXPORT_SYMBOL_GPL(nf_connlabels_put); 83