1 /* 2 * net/sched/em_text.c Textsearch ematch 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 7 * 2 of the License, or (at your option) any later version. 8 * 9 * Authors: Thomas Graf <tgraf@suug.ch> 10 */ 11 12 #include <linux/config.h> 13 #include <linux/module.h> 14 #include <linux/types.h> 15 #include <linux/kernel.h> 16 #include <linux/sched.h> 17 #include <linux/string.h> 18 #include <linux/skbuff.h> 19 #include <linux/textsearch.h> 20 #include <linux/tc_ematch/tc_em_text.h> 21 #include <net/pkt_cls.h> 22 23 struct text_match 24 { 25 u16 from_offset; 26 u16 to_offset; 27 u8 from_layer; 28 u8 to_layer; 29 struct ts_config *config; 30 }; 31 32 #define EM_TEXT_PRIV(m) ((struct text_match *) (m)->data) 33 34 static int em_text_match(struct sk_buff *skb, struct tcf_ematch *m, 35 struct tcf_pkt_info *info) 36 { 37 struct text_match *tm = EM_TEXT_PRIV(m); 38 int from, to; 39 struct ts_state state; 40 41 from = tcf_get_base_ptr(skb, tm->from_layer) - skb->data; 42 from += tm->from_offset; 43 44 to = tcf_get_base_ptr(skb, tm->to_layer) - skb->data; 45 to += tm->to_offset; 46 47 return skb_find_text(skb, from, to, tm->config, &state) != UINT_MAX; 48 } 49 50 static int em_text_change(struct tcf_proto *tp, void *data, int len, 51 struct tcf_ematch *m) 52 { 53 struct text_match *tm; 54 struct tcf_em_text *conf = data; 55 struct ts_config *ts_conf; 56 int flags = 0; 57 58 printk("Configuring text: %s from %d:%d to %d:%d len %d\n", conf->algo, conf->from_offset, 59 conf->from_layer, conf->to_offset, conf->to_layer, conf->pattern_len); 60 61 if (len < sizeof(*conf) || len < (sizeof(*conf) + conf->pattern_len)) 62 return -EINVAL; 63 64 if (conf->from_layer > conf->to_layer) 65 return -EINVAL; 66 67 if (conf->from_layer == conf->to_layer && 68 conf->from_offset > conf->to_offset) 69 return -EINVAL; 70 71 retry: 72 ts_conf = textsearch_prepare(conf->algo, (u8 *) conf + sizeof(*conf), 73 conf->pattern_len, GFP_KERNEL, flags); 74 75 if (flags & TS_AUTOLOAD) 76 rtnl_lock(); 77 78 if (IS_ERR(ts_conf)) { 79 if (PTR_ERR(ts_conf) == -ENOENT && !(flags & TS_AUTOLOAD)) { 80 rtnl_unlock(); 81 flags |= TS_AUTOLOAD; 82 goto retry; 83 } else 84 return PTR_ERR(ts_conf); 85 } else if (flags & TS_AUTOLOAD) { 86 textsearch_destroy(ts_conf); 87 return -EAGAIN; 88 } 89 90 tm = kmalloc(sizeof(*tm), GFP_KERNEL); 91 if (tm == NULL) { 92 textsearch_destroy(ts_conf); 93 return -ENOBUFS; 94 } 95 96 tm->from_offset = conf->from_offset; 97 tm->to_offset = conf->to_offset; 98 tm->from_layer = conf->from_layer; 99 tm->to_layer = conf->to_layer; 100 tm->config = ts_conf; 101 102 m->datalen = sizeof(*tm); 103 m->data = (unsigned long) tm; 104 105 return 0; 106 } 107 108 static void em_text_destroy(struct tcf_proto *tp, struct tcf_ematch *m) 109 { 110 textsearch_destroy(EM_TEXT_PRIV(m)->config); 111 } 112 113 static int em_text_dump(struct sk_buff *skb, struct tcf_ematch *m) 114 { 115 struct text_match *tm = EM_TEXT_PRIV(m); 116 struct tcf_em_text conf; 117 118 strncpy(conf.algo, tm->config->ops->name, sizeof(conf.algo) - 1); 119 conf.from_offset = tm->from_offset; 120 conf.to_offset = tm->to_offset; 121 conf.from_layer = tm->from_layer; 122 conf.to_layer = tm->to_layer; 123 conf.pattern_len = textsearch_get_pattern_len(tm->config); 124 conf.pad = 0; 125 126 RTA_PUT_NOHDR(skb, sizeof(conf), &conf); 127 RTA_APPEND(skb, conf.pattern_len, textsearch_get_pattern(tm->config)); 128 return 0; 129 130 rtattr_failure: 131 return -1; 132 } 133 134 static struct tcf_ematch_ops em_text_ops = { 135 .kind = TCF_EM_TEXT, 136 .change = em_text_change, 137 .match = em_text_match, 138 .destroy = em_text_destroy, 139 .dump = em_text_dump, 140 .owner = THIS_MODULE, 141 .link = LIST_HEAD_INIT(em_text_ops.link) 142 }; 143 144 static int __init init_em_text(void) 145 { 146 return tcf_em_register(&em_text_ops); 147 } 148 149 static void __exit exit_em_text(void) 150 { 151 tcf_em_unregister(&em_text_ops); 152 } 153 154 MODULE_LICENSE("GPL"); 155 156 module_init(init_em_text); 157 module_exit(exit_em_text); 158