1 /* 2 * Copyright (c) 2014 - 2018 The DragonFly Project. All rights reserved. 3 * 4 * This code is derived from software contributed to The DragonFly Project 5 * by Bill Yuan <bycn82@dragonflybsd.org> 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 "opt_ipfw.h" 36 #include "opt_inet.h" 37 #ifndef INET 38 #error IPFIREWALL3 requires INET. 39 #endif /* INET */ 40 41 #include <sys/systm.h> 42 #include <sys/kernel.h> 43 #include <sys/malloc.h> 44 #include <sys/socketvar.h> 45 #include <sys/sysctl.h> 46 #include <sys/systimer.h> 47 #include <sys/param.h> 48 #include <sys/ucred.h> 49 50 #include <net/if.h> 51 #include <net/bpf.h> 52 #include <net/ethernet.h> 53 #include <net/netmsg2.h> 54 #include <net/netisr2.h> 55 #include <net/route.h> 56 57 #include <netinet/in_var.h> 58 #include <netinet/ip_var.h> 59 #include <netinet/in.h> 60 #include <netinet/in_systm.h> 61 #include <netinet/in_pcb.h> 62 #include <netinet/ip.h> 63 #include <netinet/ip_icmp.h> 64 #include <netinet/tcp.h> 65 #include <netinet/tcp_timer.h> 66 #include <netinet/tcp_var.h> 67 #include <netinet/tcpip.h> 68 #include <netinet/udp.h> 69 #include <netinet/udp_var.h> 70 #include <netinet/if_ether.h> 71 72 #include <net/ipfw3/ip_fw.h> 73 74 #include "ip_fw3_layer4.h" 75 76 void 77 check_tcpflag(int *cmd_ctl, int *cmd_val, struct ip_fw_args **args, 78 struct ip_fw **f, ipfw_insn *cmd, uint16_t ip_len); 79 void 80 check_uid(int *cmd_ctl, int *cmd_val, struct ip_fw_args **args, 81 struct ip_fw **f, ipfw_insn *cmd, uint16_t ip_len); 82 void 83 check_gid(int *cmd_ctl, int *cmd_val, struct ip_fw_args **args, 84 struct ip_fw **f, ipfw_insn *cmd, uint16_t ip_len); 85 void 86 check_established(int *cmd_ctl, int *cmd_val, struct ip_fw_args **args, 87 struct ip_fw **f, ipfw_insn *cmd, uint16_t ip_len); 88 void 89 check_bpf(int *cmd_ctl, int *cmd_val, struct ip_fw_args **args, 90 struct ip_fw **f, ipfw_insn *cmd, uint16_t ip_len); 91 92 /* 93 * ip_fw3_match_guid can match the gui and uid 94 */ 95 static int 96 ip_fw3_match_guid(const struct ipfw_flow_id *fid, struct ifnet *oif, 97 int opcode, uid_t uid) 98 { 99 struct in_addr src_ip, dst_ip; 100 struct inpcbinfo *pi; 101 boolean_t wildcard; 102 struct inpcb *pcb; 103 104 if (fid->proto == IPPROTO_TCP) { 105 wildcard = FALSE; 106 pi = &tcbinfo[mycpuid]; 107 } else if (fid->proto == IPPROTO_UDP) { 108 wildcard = TRUE; 109 pi = &udbinfo[mycpuid]; 110 } else { 111 return 0; 112 } 113 114 /* 115 * Values in 'fid' are in host byte order 116 */ 117 dst_ip.s_addr = htonl(fid->dst_ip); 118 src_ip.s_addr = htonl(fid->src_ip); 119 if (oif) { 120 pcb = in_pcblookup_hash(pi, 121 dst_ip, htons(fid->dst_port), 122 src_ip, htons(fid->src_port), 123 wildcard, oif); 124 } else { 125 pcb = in_pcblookup_hash(pi, 126 src_ip, htons(fid->src_port), 127 dst_ip, htons(fid->dst_port), 128 wildcard, NULL); 129 } 130 if (pcb == NULL || pcb->inp_socket == NULL) { 131 return 0; 132 } 133 134 if (opcode == O_LAYER4_UID) { 135 #define socheckuid(a,b) ((a)->so_cred->cr_uid != (b)) 136 return !socheckuid(pcb->inp_socket, uid); 137 #undef socheckuid 138 } else { 139 return groupmember(uid, pcb->inp_socket->so_cred); 140 } 141 } 142 143 void 144 check_tcpflag(int *cmd_ctl, int *cmd_val, struct ip_fw_args **args, 145 struct ip_fw **f, ipfw_insn *cmd, uint16_t ip_len) 146 { 147 /* XXX TODO check tcpflag */ 148 *cmd_val = 0; 149 *cmd_ctl = IP_FW_CTL_NO; 150 } 151 152 void 153 check_uid(int *cmd_ctl, int *cmd_val, struct ip_fw_args **args, 154 struct ip_fw **f, ipfw_insn *cmd, uint16_t ip_len) 155 { 156 *cmd_val = ip_fw3_match_guid(&(*args)->f_id, (*args)->oif, cmd->opcode, 157 (uid_t)((ipfw_insn_u32 *)cmd)->d[0]); 158 *cmd_ctl = IP_FW_CTL_NO; 159 } 160 161 void 162 check_gid(int *cmd_ctl, int *cmd_val, struct ip_fw_args **args, 163 struct ip_fw **f, ipfw_insn *cmd, uint16_t ip_len) 164 { 165 *cmd_val = ip_fw3_match_guid(&(*args)->f_id, (*args)->oif, cmd->opcode, 166 (gid_t)((ipfw_insn_u32 *)cmd)->d[0]); 167 *cmd_ctl = IP_FW_CTL_NO; 168 } 169 170 /* 171 * match TCP packets which have all tcpflag except SYN. 172 */ 173 void check_established(int *cmd_ctl, int *cmd_val, struct ip_fw_args **args, 174 struct ip_fw **f, ipfw_insn *cmd, uint16_t ip_len) 175 { 176 struct ipfw_flow_id *fid; 177 struct mbuf *m = (*args)->m; 178 struct ip *ip = mtod(m, struct ip *); 179 180 *cmd_ctl = IP_FW_CTL_NO; 181 fid = &(*args)->f_id; 182 if (fid->proto == IPPROTO_TCP) { 183 /* offset == 0 && */ 184 if ((L3HDR(struct tcphdr, ip)->th_flags & 185 (TH_RST | TH_ACK | TH_SYN)) != TH_SYN) { 186 *cmd_val = IP_FW_MATCH; 187 return; 188 } 189 } 190 *cmd_val = IP_FW_NOT_MATCH; 191 } 192 193 void 194 check_bpf(int *cmd_ctl, int *cmd_val, struct ip_fw_args **args, 195 struct ip_fw **f, ipfw_insn *cmd, uint16_t ip_len) 196 { 197 u_int slen = 0; 198 struct mbuf *m = (*args)->m; 199 ipfw_insn_bpf *bpf = (ipfw_insn_bpf *)cmd; 200 *cmd_ctl = IP_FW_CTL_NO; 201 slen = bpf_filter(bpf->bf_insn, (u_char *)m, m_lengthm(m, NULL), 0); 202 if (slen != 0) 203 *cmd_val = IP_FW_MATCH; 204 else 205 *cmd_val = IP_FW_NOT_MATCH; 206 } 207 208 209 static int 210 ip_fw3_layer4_init(void) 211 { 212 ip_fw3_register_module(MODULE_LAYER4_ID, MODULE_LAYER4_NAME); 213 ip_fw3_register_filter_funcs(MODULE_LAYER4_ID, O_LAYER4_TCPFLAG, 214 (filter_func)check_tcpflag); 215 ip_fw3_register_filter_funcs(MODULE_LAYER4_ID, O_LAYER4_UID, 216 (filter_func)check_uid); 217 ip_fw3_register_filter_funcs(MODULE_LAYER4_ID, O_LAYER4_GID, 218 (filter_func)check_gid); 219 ip_fw3_register_filter_funcs(MODULE_LAYER4_ID, O_LAYER4_ESTABLISHED, 220 (filter_func)check_established); 221 ip_fw3_register_filter_funcs(MODULE_LAYER4_ID, O_LAYER4_BPF, 222 (filter_func)check_bpf); 223 return 0; 224 } 225 226 static int 227 ip_fw3_layer4_stop(void) 228 { 229 return ip_fw3_unregister_module(MODULE_LAYER4_ID); 230 } 231 232 static int 233 ipfw3_layer4_modevent(module_t mod, int type, void *data) 234 { 235 switch (type) { 236 case MOD_LOAD: 237 return ip_fw3_layer4_init(); 238 case MOD_UNLOAD: 239 return ip_fw3_layer4_stop(); 240 default: 241 break; 242 } 243 return 0; 244 } 245 246 static moduledata_t ipfw3_layer4_mod = { 247 "ipfw3_layer4", 248 ipfw3_layer4_modevent, 249 NULL 250 }; 251 DECLARE_MODULE(ipfw3_layer4, ipfw3_layer4_mod, SI_SUB_PROTO_END, SI_ORDER_ANY); 252 MODULE_DEPEND(ipfw3_layer4, ipfw3_basic, 1, 1, 1); 253 MODULE_VERSION(ipfw3_layer4, 1); 254