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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
d675c989 TG |
2 | /* |
3 | * net/sched/em_text.c Textsearch ematch | |
4 | * | |
d675c989 TG |
5 | * Authors: Thomas Graf <tgraf@suug.ch> |
6 | */ | |
7 | ||
5a0e3ad6 | 8 | #include <linux/slab.h> |
d675c989 TG |
9 | #include <linux/module.h> |
10 | #include <linux/types.h> | |
11 | #include <linux/kernel.h> | |
d675c989 TG |
12 | #include <linux/string.h> |
13 | #include <linux/skbuff.h> | |
14 | #include <linux/textsearch.h> | |
15 | #include <linux/tc_ematch/tc_em_text.h> | |
16 | #include <net/pkt_cls.h> | |
17 | ||
cc7ec456 | 18 | struct text_match { |
d675c989 TG |
19 | u16 from_offset; |
20 | u16 to_offset; | |
21 | u8 from_layer; | |
22 | u8 to_layer; | |
23 | struct ts_config *config; | |
24 | }; | |
25 | ||
26 | #define EM_TEXT_PRIV(m) ((struct text_match *) (m)->data) | |
27 | ||
28 | static int em_text_match(struct sk_buff *skb, struct tcf_ematch *m, | |
29 | struct tcf_pkt_info *info) | |
30 | { | |
31 | struct text_match *tm = EM_TEXT_PRIV(m); | |
32 | int from, to; | |
d675c989 TG |
33 | |
34 | from = tcf_get_base_ptr(skb, tm->from_layer) - skb->data; | |
35 | from += tm->from_offset; | |
36 | ||
37 | to = tcf_get_base_ptr(skb, tm->to_layer) - skb->data; | |
38 | to += tm->to_offset; | |
39 | ||
059a2440 | 40 | return skb_find_text(skb, from, to, tm->config) != UINT_MAX; |
d675c989 TG |
41 | } |
42 | ||
82a470f1 | 43 | static int em_text_change(struct net *net, void *data, int len, |
d675c989 TG |
44 | struct tcf_ematch *m) |
45 | { | |
46 | struct text_match *tm; | |
47 | struct tcf_em_text *conf = data; | |
48 | struct ts_config *ts_conf; | |
49 | int flags = 0; | |
50 | ||
d675c989 TG |
51 | if (len < sizeof(*conf) || len < (sizeof(*conf) + conf->pattern_len)) |
52 | return -EINVAL; | |
53 | ||
54 | if (conf->from_layer > conf->to_layer) | |
55 | return -EINVAL; | |
56 | ||
57 | if (conf->from_layer == conf->to_layer && | |
58 | conf->from_offset > conf->to_offset) | |
59 | return -EINVAL; | |
60 | ||
61 | retry: | |
62 | ts_conf = textsearch_prepare(conf->algo, (u8 *) conf + sizeof(*conf), | |
63 | conf->pattern_len, GFP_KERNEL, flags); | |
64 | ||
65 | if (flags & TS_AUTOLOAD) | |
66 | rtnl_lock(); | |
67 | ||
68 | if (IS_ERR(ts_conf)) { | |
69 | if (PTR_ERR(ts_conf) == -ENOENT && !(flags & TS_AUTOLOAD)) { | |
70 | rtnl_unlock(); | |
71 | flags |= TS_AUTOLOAD; | |
72 | goto retry; | |
73 | } else | |
74 | return PTR_ERR(ts_conf); | |
75 | } else if (flags & TS_AUTOLOAD) { | |
76 | textsearch_destroy(ts_conf); | |
77 | return -EAGAIN; | |
78 | } | |
79 | ||
80 | tm = kmalloc(sizeof(*tm), GFP_KERNEL); | |
81 | if (tm == NULL) { | |
82 | textsearch_destroy(ts_conf); | |
83 | return -ENOBUFS; | |
84 | } | |
85 | ||
86 | tm->from_offset = conf->from_offset; | |
87 | tm->to_offset = conf->to_offset; | |
88 | tm->from_layer = conf->from_layer; | |
89 | tm->to_layer = conf->to_layer; | |
90 | tm->config = ts_conf; | |
91 | ||
92 | m->datalen = sizeof(*tm); | |
93 | m->data = (unsigned long) tm; | |
94 | ||
95 | return 0; | |
96 | } | |
97 | ||
82a470f1 | 98 | static void em_text_destroy(struct tcf_ematch *m) |
d675c989 | 99 | { |
5ec1cea0 TG |
100 | if (EM_TEXT_PRIV(m) && EM_TEXT_PRIV(m)->config) |
101 | textsearch_destroy(EM_TEXT_PRIV(m)->config); | |
d675c989 TG |
102 | } |
103 | ||
104 | static int em_text_dump(struct sk_buff *skb, struct tcf_ematch *m) | |
105 | { | |
106 | struct text_match *tm = EM_TEXT_PRIV(m); | |
107 | struct tcf_em_text conf; | |
108 | ||
109 | strncpy(conf.algo, tm->config->ops->name, sizeof(conf.algo) - 1); | |
110 | conf.from_offset = tm->from_offset; | |
111 | conf.to_offset = tm->to_offset; | |
112 | conf.from_layer = tm->from_layer; | |
113 | conf.to_layer = tm->to_layer; | |
114 | conf.pattern_len = textsearch_get_pattern_len(tm->config); | |
115 | conf.pad = 0; | |
116 | ||
add93b61 PM |
117 | if (nla_put_nohdr(skb, sizeof(conf), &conf) < 0) |
118 | goto nla_put_failure; | |
119 | if (nla_append(skb, conf.pattern_len, | |
120 | textsearch_get_pattern(tm->config)) < 0) | |
121 | goto nla_put_failure; | |
d675c989 TG |
122 | return 0; |
123 | ||
add93b61 | 124 | nla_put_failure: |
d675c989 | 125 | return -1; |
10297b99 | 126 | } |
d675c989 TG |
127 | |
128 | static struct tcf_ematch_ops em_text_ops = { | |
129 | .kind = TCF_EM_TEXT, | |
130 | .change = em_text_change, | |
131 | .match = em_text_match, | |
132 | .destroy = em_text_destroy, | |
133 | .dump = em_text_dump, | |
134 | .owner = THIS_MODULE, | |
135 | .link = LIST_HEAD_INIT(em_text_ops.link) | |
136 | }; | |
137 | ||
138 | static int __init init_em_text(void) | |
139 | { | |
140 | return tcf_em_register(&em_text_ops); | |
141 | } | |
142 | ||
10297b99 | 143 | static void __exit exit_em_text(void) |
d675c989 TG |
144 | { |
145 | tcf_em_unregister(&em_text_ops); | |
146 | } | |
147 | ||
148 | MODULE_LICENSE("GPL"); | |
149 | ||
150 | module_init(init_em_text); | |
151 | module_exit(exit_em_text); | |
db3d99c0 PM |
152 | |
153 | MODULE_ALIAS_TCF_EMATCH(TCF_EM_TEXT); |