1 /* 2 * Copyright (c) 2015 The DragonFly Project. All rights reserved. 3 * 4 * This code is derived from software contributed to The DragonFly Project 5 * by Bill Yuan <bycn82@gmail.com> 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in 15 * the documentation and/or other materials provided with the 16 * distribution. 17 * 3. Neither the name of The DragonFly Project nor the names of its 18 * contributors may be used to endorse or promote products derived 19 * from this software without specific, prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #include <sys/systm.h> 36 #include <sys/kernel.h> 37 #include <sys/malloc.h> 38 #include <sys/socketvar.h> 39 #include <sys/sysctl.h> 40 #include <sys/systimer.h> 41 #include <sys/param.h> 42 #include <sys/ucred.h> 43 44 #include <netinet/in_var.h> 45 #include <netinet/ip_var.h> 46 #include <netinet/in.h> 47 #include <netinet/in_systm.h> 48 #include <netinet/in_var.h> 49 #include <netinet/in_pcb.h> 50 #include <netinet/ip.h> 51 #include <netinet/ip_var.h> 52 #include <netinet/ip_icmp.h> 53 #include <netinet/tcp.h> 54 #include <netinet/tcp_timer.h> 55 #include <netinet/tcp_var.h> 56 #include <netinet/tcpip.h> 57 #include <netinet/udp.h> 58 #include <netinet/udp_var.h> 59 #include <netinet/if_ether.h> 60 61 #include <net/bpf.h> 62 #include <net/ethernet.h> 63 #include <net/netmsg2.h> 64 #include <net/netisr2.h> 65 #include <net/route.h> 66 67 #include <net/ipfw3/ip_fw.h> 68 69 #include "ip_fw3_layer4.h" 70 71 void 72 check_tcpflag(int *cmd_ctl, int *cmd_val, struct ip_fw_args **args, 73 struct ip_fw **f, ipfw_insn *cmd, uint16_t ip_len); 74 void 75 check_uid(int *cmd_ctl, int *cmd_val, struct ip_fw_args **args, 76 struct ip_fw **f, ipfw_insn *cmd, uint16_t ip_len); 77 void 78 check_gid(int *cmd_ctl, int *cmd_val, struct ip_fw_args **args, 79 struct ip_fw **f, ipfw_insn *cmd, uint16_t ip_len); 80 void 81 check_established(int *cmd_ctl, int *cmd_val, struct ip_fw_args **args, 82 struct ip_fw **f, ipfw_insn *cmd, uint16_t ip_len); 83 void 84 check_bpf(int *cmd_ctl, int *cmd_val, struct ip_fw_args **args, 85 struct ip_fw **f, ipfw_insn *cmd, uint16_t ip_len); 86 87 /* 88 * ipfw_match_guid can match the gui and uid 89 */ 90 static int 91 ipfw_match_guid(const struct ipfw_flow_id *fid, struct ifnet *oif, 92 int opcode, uid_t uid) 93 { 94 struct in_addr src_ip, dst_ip; 95 struct inpcbinfo *pi; 96 boolean_t wildcard; 97 struct inpcb *pcb; 98 99 if (fid->proto == IPPROTO_TCP) { 100 wildcard = FALSE; 101 pi = &tcbinfo[mycpuid]; 102 } else if (fid->proto == IPPROTO_UDP) { 103 wildcard = TRUE; 104 pi = &udbinfo[mycpuid]; 105 } else { 106 return 0; 107 } 108 109 /* 110 * Values in 'fid' are in host byte order 111 */ 112 dst_ip.s_addr = htonl(fid->dst_ip); 113 src_ip.s_addr = htonl(fid->src_ip); 114 if (oif) { 115 pcb = in_pcblookup_hash(pi, 116 dst_ip, htons(fid->dst_port), 117 src_ip, htons(fid->src_port), 118 wildcard, oif); 119 } else { 120 pcb = in_pcblookup_hash(pi, 121 src_ip, htons(fid->src_port), 122 dst_ip, htons(fid->dst_port), 123 wildcard, NULL); 124 } 125 if (pcb == NULL || pcb->inp_socket == NULL) { 126 return 0; 127 } 128 129 if (opcode == O_LAYER4_UID) { 130 #define socheckuid(a,b) ((a)->so_cred->cr_uid != (b)) 131 return !socheckuid(pcb->inp_socket, uid); 132 #undef socheckuid 133 } else { 134 return groupmember(uid, pcb->inp_socket->so_cred); 135 } 136 } 137 138 void 139 check_tcpflag(int *cmd_ctl, int *cmd_val, struct ip_fw_args **args, 140 struct ip_fw **f, ipfw_insn *cmd, uint16_t ip_len) 141 { 142 /* XXX TODO check tcpflag */ 143 *cmd_val = 0; 144 *cmd_ctl = IP_FW_CTL_NO; 145 } 146 147 void 148 check_uid(int *cmd_ctl, int *cmd_val, struct ip_fw_args **args, 149 struct ip_fw **f, ipfw_insn *cmd, uint16_t ip_len) 150 { 151 *cmd_val = ipfw_match_guid(&(*args)->f_id, (*args)->oif, cmd->opcode, 152 (uid_t)((ipfw_insn_u32 *)cmd)->d[0]); 153 *cmd_ctl = IP_FW_CTL_NO; 154 } 155 156 void 157 check_gid(int *cmd_ctl, int *cmd_val, struct ip_fw_args **args, 158 struct ip_fw **f, ipfw_insn *cmd, uint16_t ip_len) 159 { 160 *cmd_val = ipfw_match_guid(&(*args)->f_id, (*args)->oif, cmd->opcode, 161 (gid_t)((ipfw_insn_u32 *)cmd)->d[0]); 162 *cmd_ctl = IP_FW_CTL_NO; 163 } 164 165 /* 166 * match TCP packets which have all tcpflag except SYN. 167 */ 168 void check_established(int *cmd_ctl, int *cmd_val, struct ip_fw_args **args, 169 struct ip_fw **f, ipfw_insn *cmd, uint16_t ip_len) 170 { 171 struct ipfw_flow_id *fid; 172 struct mbuf *m = (*args)->m; 173 struct ip *ip = mtod(m, struct ip *); 174 175 *cmd_ctl = IP_FW_CTL_NO; 176 fid = &(*args)->f_id; 177 if (fid->proto == IPPROTO_TCP) { 178 /* offset == 0 && */ 179 if ((L3HDR(struct tcphdr, ip)->th_flags & 180 (TH_RST | TH_ACK | TH_SYN)) != TH_SYN) { 181 *cmd_val = IP_FW_MATCH; 182 return; 183 } 184 } 185 *cmd_val = IP_FW_NOT_MATCH; 186 } 187 188 void 189 check_bpf(int *cmd_ctl, int *cmd_val, struct ip_fw_args **args, 190 struct ip_fw **f, ipfw_insn *cmd, uint16_t ip_len) 191 { 192 u_int slen = 0; 193 struct mbuf *m = (*args)->m; 194 ipfw_insn_bpf *bpf = (ipfw_insn_bpf *)cmd; 195 *cmd_ctl = IP_FW_CTL_NO; 196 slen = bpf_filter(bpf->bf_insn, (u_char *)m, m_lengthm(m, NULL), 0); 197 if (slen != 0) 198 *cmd_val = IP_FW_MATCH; 199 else 200 *cmd_val = IP_FW_NOT_MATCH; 201 } 202 203 204 static int 205 ipfw3_layer4_init(void) 206 { 207 register_ipfw_module(MODULE_LAYER4_ID, MODULE_LAYER4_NAME); 208 register_ipfw_filter_funcs(MODULE_LAYER4_ID, O_LAYER4_TCPFLAG, 209 (filter_func)check_tcpflag); 210 register_ipfw_filter_funcs(MODULE_LAYER4_ID, O_LAYER4_UID, 211 (filter_func)check_uid); 212 register_ipfw_filter_funcs(MODULE_LAYER4_ID, O_LAYER4_GID, 213 (filter_func)check_gid); 214 register_ipfw_filter_funcs(MODULE_LAYER4_ID, O_LAYER4_ESTABLISHED, 215 (filter_func)check_established); 216 register_ipfw_filter_funcs(MODULE_LAYER4_ID, O_LAYER4_BPF, 217 (filter_func)check_bpf); 218 return 0; 219 } 220 221 static int 222 ipfw3_layer4_stop(void) 223 { 224 return unregister_ipfw_module(MODULE_LAYER4_ID); 225 } 226 227 static int 228 ipfw3_layer4_modevent(module_t mod, int type, void *data) 229 { 230 switch (type) { 231 case MOD_LOAD: 232 return ipfw3_layer4_init(); 233 case MOD_UNLOAD: 234 return ipfw3_layer4_stop(); 235 default: 236 break; 237 } 238 return 0; 239 } 240 241 static moduledata_t ipfw3_layer4_mod = { 242 "ipfw3_layer4", 243 ipfw3_layer4_modevent, 244 NULL 245 }; 246 DECLARE_MODULE(ipfw3_layer4, ipfw3_layer4_mod, SI_SUB_PROTO_END, SI_ORDER_ANY); 247 MODULE_DEPEND(ipfw3_layer4, ipfw3_basic, 1, 1, 1); 248 MODULE_VERSION(ipfw3_layer4, 1); 249