| 1 | // SPDX-License-Identifier: GPL-2.0-or-later | 
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| 2 | /* | 
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| 3 | * INET		An implementation of the TCP/IP protocol suite for the LINUX | 
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| 4 | *		operating system.  INET is implemented using the  BSD Socket | 
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| 5 | *		interface as the means of communication with the user level. | 
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| 6 | * | 
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| 7 | *		INET protocol dispatch tables. | 
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| 8 | * | 
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| 9 | * Authors:	Ross Biro | 
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| 10 | *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> | 
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| 11 | * | 
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| 12 | * Fixes: | 
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| 13 | *		Alan Cox	: Ahah! udp icmp errors don't work because | 
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| 14 | *				  udp_err is never called! | 
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| 15 | *		Alan Cox	: Added new fields for init and ready for | 
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| 16 | *				  proper fragmentation (_NO_ 4K limits!) | 
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| 17 | *		Richard Colella	: Hang on hash collision | 
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| 18 | *		Vince Laviano	: Modified inet_del_protocol() to correctly | 
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| 19 | *				  maintain copy bit. | 
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| 20 | */ | 
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| 21 | #include <linux/cache.h> | 
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| 22 | #include <linux/module.h> | 
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| 23 | #include <linux/netdevice.h> | 
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| 24 | #include <linux/spinlock.h> | 
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| 25 | #include <net/protocol.h> | 
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| 26 |  | 
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| 27 | struct net_protocol __rcu *inet_protos[MAX_INET_PROTOS] __read_mostly; | 
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| 28 | EXPORT_SYMBOL(inet_protos); | 
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| 29 | const struct net_offload __rcu *inet_offloads[MAX_INET_PROTOS] __read_mostly; | 
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| 30 | EXPORT_SYMBOL(inet_offloads); | 
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| 31 |  | 
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| 32 | int inet_add_protocol(const struct net_protocol *prot, unsigned char protocol) | 
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| 33 | { | 
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| 34 | return !cmpxchg((const struct net_protocol **)&inet_protos[protocol], | 
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| 35 | NULL, prot) ? 0 : -1; | 
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| 36 | } | 
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| 37 | EXPORT_SYMBOL(inet_add_protocol); | 
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| 38 |  | 
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| 39 | int inet_add_offload(const struct net_offload *prot, unsigned char protocol) | 
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| 40 | { | 
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| 41 | return !cmpxchg((const struct net_offload **)&inet_offloads[protocol], | 
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| 42 | NULL, prot) ? 0 : -1; | 
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| 43 | } | 
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| 44 | EXPORT_SYMBOL(inet_add_offload); | 
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| 45 |  | 
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| 46 | int inet_del_protocol(const struct net_protocol *prot, unsigned char protocol) | 
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| 47 | { | 
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| 48 | int ret; | 
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| 49 |  | 
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| 50 | ret = (cmpxchg((const struct net_protocol **)&inet_protos[protocol], | 
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| 51 | prot, NULL) == prot) ? 0 : -1; | 
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| 52 |  | 
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| 53 | synchronize_net(); | 
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| 54 |  | 
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| 55 | return ret; | 
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| 56 | } | 
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| 57 | EXPORT_SYMBOL(inet_del_protocol); | 
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| 58 |  | 
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| 59 | int inet_del_offload(const struct net_offload *prot, unsigned char protocol) | 
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| 60 | { | 
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| 61 | int ret; | 
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| 62 |  | 
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| 63 | ret = (cmpxchg((const struct net_offload **)&inet_offloads[protocol], | 
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| 64 | prot, NULL) == prot) ? 0 : -1; | 
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| 65 |  | 
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| 66 | synchronize_net(); | 
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| 67 |  | 
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| 68 | return ret; | 
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| 69 | } | 
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| 70 | EXPORT_SYMBOL(inet_del_offload); | 
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| 71 |  | 
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