.. | .. |
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| 1 | +// SPDX-License-Identifier: GPL-2.0-only |
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1 | 2 | /* |
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2 | 3 | * Pluggable TCP upper layer protocol support. |
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3 | 4 | * |
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.. | .. |
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6 | 7 | * |
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7 | 8 | */ |
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8 | 9 | |
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9 | | -#include<linux/module.h> |
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| 10 | +#include <linux/module.h> |
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10 | 11 | #include <linux/mm.h> |
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11 | 12 | #include <linux/types.h> |
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12 | 13 | #include <linux/list.h> |
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.. | .. |
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21 | 22 | { |
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22 | 23 | struct tcp_ulp_ops *e; |
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23 | 24 | |
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24 | | - list_for_each_entry_rcu(e, &tcp_ulp_list, list) { |
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| 25 | + list_for_each_entry_rcu(e, &tcp_ulp_list, list, |
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| 26 | + lockdep_is_held(&tcp_ulp_list_lock)) { |
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25 | 27 | if (strcmp(e->name, name) == 0) |
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26 | | - return e; |
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27 | | - } |
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28 | | - |
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29 | | - return NULL; |
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30 | | -} |
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31 | | - |
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32 | | -static struct tcp_ulp_ops *tcp_ulp_find_id(const int ulp) |
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33 | | -{ |
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34 | | - struct tcp_ulp_ops *e; |
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35 | | - |
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36 | | - list_for_each_entry_rcu(e, &tcp_ulp_list, list) { |
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37 | | - if (e->uid == ulp) |
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38 | 28 | return e; |
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39 | 29 | } |
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40 | 30 | |
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.. | .. |
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59 | 49 | if (!ulp || !try_module_get(ulp->owner)) |
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60 | 50 | ulp = NULL; |
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61 | 51 | |
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62 | | - rcu_read_unlock(); |
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63 | | - return ulp; |
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64 | | -} |
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65 | | - |
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66 | | -static const struct tcp_ulp_ops *__tcp_ulp_lookup(const int uid) |
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67 | | -{ |
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68 | | - const struct tcp_ulp_ops *ulp; |
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69 | | - |
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70 | | - rcu_read_lock(); |
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71 | | - ulp = tcp_ulp_find_id(uid); |
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72 | | - if (!ulp || !try_module_get(ulp->owner)) |
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73 | | - ulp = NULL; |
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74 | 52 | rcu_read_unlock(); |
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75 | 53 | return ulp; |
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76 | 54 | } |
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.. | .. |
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115 | 93 | offs += snprintf(buf + offs, maxlen - offs, |
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116 | 94 | "%s%s", |
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117 | 95 | offs == 0 ? "" : " ", ulp_ops->name); |
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| 96 | + |
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| 97 | + if (WARN_ON_ONCE(offs >= maxlen)) |
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| 98 | + break; |
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118 | 99 | } |
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119 | 100 | rcu_read_unlock(); |
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| 101 | +} |
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| 102 | + |
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| 103 | +void tcp_update_ulp(struct sock *sk, struct proto *proto, |
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| 104 | + void (*write_space)(struct sock *sk)) |
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| 105 | +{ |
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| 106 | + struct inet_connection_sock *icsk = inet_csk(sk); |
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| 107 | + |
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| 108 | + if (icsk->icsk_ulp_ops->update) |
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| 109 | + icsk->icsk_ulp_ops->update(sk, proto, write_space); |
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120 | 110 | } |
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121 | 111 | |
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122 | 112 | void tcp_cleanup_ulp(struct sock *sk) |
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123 | 113 | { |
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124 | 114 | struct inet_connection_sock *icsk = inet_csk(sk); |
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125 | 115 | |
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| 116 | + /* No sock_owned_by_me() check here as at the time the |
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| 117 | + * stack calls this function, the socket is dead and |
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| 118 | + * about to be destroyed. |
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| 119 | + */ |
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126 | 120 | if (!icsk->icsk_ulp_ops) |
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127 | 121 | return; |
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128 | 122 | |
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.. | .. |
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133 | 127 | icsk->icsk_ulp_ops = NULL; |
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134 | 128 | } |
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135 | 129 | |
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136 | | -/* Change upper layer protocol for socket */ |
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137 | | -int tcp_set_ulp(struct sock *sk, const char *name) |
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| 130 | +static int __tcp_set_ulp(struct sock *sk, const struct tcp_ulp_ops *ulp_ops) |
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138 | 131 | { |
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139 | 132 | struct inet_connection_sock *icsk = inet_csk(sk); |
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140 | | - const struct tcp_ulp_ops *ulp_ops; |
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141 | | - int err = 0; |
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| 133 | + int err; |
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142 | 134 | |
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| 135 | + err = -EEXIST; |
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143 | 136 | if (icsk->icsk_ulp_ops) |
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144 | | - return -EEXIST; |
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| 137 | + goto out_err; |
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| 138 | + |
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| 139 | + err = -ENOTCONN; |
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| 140 | + if (!ulp_ops->clone && sk->sk_state == TCP_LISTEN) |
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| 141 | + goto out_err; |
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| 142 | + |
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| 143 | + err = ulp_ops->init(sk); |
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| 144 | + if (err) |
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| 145 | + goto out_err; |
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| 146 | + |
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| 147 | + icsk->icsk_ulp_ops = ulp_ops; |
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| 148 | + return 0; |
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| 149 | +out_err: |
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| 150 | + module_put(ulp_ops->owner); |
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| 151 | + return err; |
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| 152 | +} |
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| 153 | + |
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| 154 | +int tcp_set_ulp(struct sock *sk, const char *name) |
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| 155 | +{ |
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| 156 | + const struct tcp_ulp_ops *ulp_ops; |
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| 157 | + |
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| 158 | + sock_owned_by_me(sk); |
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145 | 159 | |
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146 | 160 | ulp_ops = __tcp_ulp_find_autoload(name); |
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147 | 161 | if (!ulp_ops) |
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148 | 162 | return -ENOENT; |
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149 | 163 | |
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150 | | - if (!ulp_ops->user_visible) { |
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151 | | - module_put(ulp_ops->owner); |
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152 | | - return -ENOENT; |
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153 | | - } |
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154 | | - |
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155 | | - err = ulp_ops->init(sk); |
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156 | | - if (err) { |
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157 | | - module_put(ulp_ops->owner); |
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158 | | - return err; |
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159 | | - } |
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160 | | - |
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161 | | - icsk->icsk_ulp_ops = ulp_ops; |
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162 | | - return 0; |
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163 | | -} |
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164 | | - |
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165 | | -int tcp_set_ulp_id(struct sock *sk, int ulp) |
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166 | | -{ |
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167 | | - struct inet_connection_sock *icsk = inet_csk(sk); |
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168 | | - const struct tcp_ulp_ops *ulp_ops; |
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169 | | - int err; |
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170 | | - |
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171 | | - if (icsk->icsk_ulp_ops) |
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172 | | - return -EEXIST; |
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173 | | - |
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174 | | - ulp_ops = __tcp_ulp_lookup(ulp); |
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175 | | - if (!ulp_ops) |
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176 | | - return -ENOENT; |
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177 | | - |
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178 | | - err = ulp_ops->init(sk); |
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179 | | - if (err) { |
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180 | | - module_put(ulp_ops->owner); |
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181 | | - return err; |
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182 | | - } |
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183 | | - |
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184 | | - icsk->icsk_ulp_ops = ulp_ops; |
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185 | | - return 0; |
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| 164 | + return __tcp_set_ulp(sk, ulp_ops); |
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186 | 165 | } |
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