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https://git.FreeBSD.org/src.git
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2f9a21326c
Make a sonewconn3() which takes an extra argument (proc) so new sockets created with sonewconn() from a user's system call get the correct credentials, not just the parent's credentials.
1538 lines
38 KiB
C
1538 lines
38 KiB
C
/*
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* Copyright (c) 1993 Daniel Boulet
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* Copyright (c) 1994 Ugen J.S.Antsilevich
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* Copyright (c) 1996 Alex Nash
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*
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* Redistribution and use in source forms, with and without modification,
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* are permitted provided that this entire comment appears intact.
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*
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* Redistribution in binary form may occur without any restrictions.
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* Obviously, it would be nice if you gave credit where credit is due
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* but requiring it would be too onerous.
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*
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* This software is provided ``AS IS'' without any warranties of any kind.
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*
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* $FreeBSD$
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*/
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/*
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* Implement IP packet firewall
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*/
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#if !defined(KLD_MODULE)
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#include "opt_ipfw.h"
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#include "opt_ipdn.h"
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#include "opt_ipdivert.h"
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#include "opt_inet.h"
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#ifndef INET
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#error IPFIREWALL requires INET.
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#endif /* INET */
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#endif
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/malloc.h>
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#include <sys/mbuf.h>
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#include <sys/kernel.h>
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#include <sys/proc.h>
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#include <sys/socket.h>
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#include <sys/socketvar.h>
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#include <sys/sysctl.h>
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#include <sys/syslog.h>
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#include <sys/ucred.h>
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#include <net/if.h>
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#include <net/route.h>
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#include <netinet/in.h>
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#include <netinet/in_systm.h>
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#include <netinet/in_pcb.h>
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#include <netinet/ip.h>
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#include <netinet/ip_var.h>
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#include <netinet/ip_icmp.h>
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#include <netinet/ip_fw.h>
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#ifdef DUMMYNET
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#include <netinet/ip_dummynet.h>
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#endif
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#include <netinet/tcp.h>
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#include <netinet/tcp_timer.h>
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#include <netinet/tcp_var.h>
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#include <netinet/tcpip.h>
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#include <netinet/udp.h>
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#include <netinet/udp_var.h>
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#include <netinet/if_ether.h> /* XXX ethertype_ip */
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static int fw_debug = 1;
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#ifdef IPFIREWALL_VERBOSE
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static int fw_verbose = 1;
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#else
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static int fw_verbose = 0;
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#endif
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static int fw_one_pass = 1 ;
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#ifdef IPFIREWALL_VERBOSE_LIMIT
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static int fw_verbose_limit = IPFIREWALL_VERBOSE_LIMIT;
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#else
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static int fw_verbose_limit = 0;
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#endif
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static u_int64_t counter; /* counter for ipfw_report(NULL...) */
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#define IPFW_DEFAULT_RULE ((u_int)(u_short)~0)
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LIST_HEAD (ip_fw_head, ip_fw_chain) ip_fw_chain;
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MALLOC_DEFINE(M_IPFW, "IpFw/IpAcct", "IpFw/IpAcct chain's");
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#ifdef SYSCTL_NODE
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SYSCTL_DECL(_net_inet_ip);
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SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall");
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SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, debug, CTLFLAG_RW,
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&fw_debug, 0, "Enable printing of debug ip_fw statements");
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SYSCTL_INT(_net_inet_ip_fw, OID_AUTO,one_pass,CTLFLAG_RW,
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&fw_one_pass, 0,
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"Only do a single pass through ipfw rules when using divert(4)");
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SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose, CTLFLAG_RW,
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&fw_verbose, 0, "Log matches to ipfw rules");
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SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit, CTLFLAG_RW,
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&fw_verbose_limit, 0, "Set upper limit of matches of ipfw rules logged");
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#endif
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#define dprintf(a) do { \
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if (fw_debug) \
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printf a; \
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} while (0)
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#define SNPARGS(buf, len) buf + len, sizeof(buf) > len ? sizeof(buf) - len : 0
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static int add_entry __P((struct ip_fw_head *chainptr, struct ip_fw *frwl));
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static int del_entry __P((struct ip_fw_head *chainptr, u_short number));
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static int zero_entry __P((struct ip_fw *));
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static int resetlog_entry __P((struct ip_fw *));
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static int check_ipfw_struct __P((struct ip_fw *m));
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static __inline int
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iface_match __P((struct ifnet *ifp, union ip_fw_if *ifu,
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int byname));
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static int ipopts_match __P((struct ip *ip, struct ip_fw *f));
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static __inline int
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port_match __P((u_short *portptr, int nports, u_short port,
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int range_flag));
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static int tcpflg_match __P((struct tcphdr *tcp, struct ip_fw *f));
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static int icmptype_match __P((struct icmp * icmp, struct ip_fw * f));
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static void ipfw_report __P((struct ip_fw *f, struct ip *ip,
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struct ifnet *rif, struct ifnet *oif));
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static void flush_rule_ptrs(void);
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static int ip_fw_chk __P((struct ip **pip, int hlen,
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struct ifnet *oif, u_int16_t *cookie, struct mbuf **m,
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struct ip_fw_chain **flow_id,
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struct sockaddr_in **next_hop));
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static int ip_fw_ctl __P((struct sockopt *sopt));
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static char err_prefix[] = "ip_fw_ctl:";
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/*
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* Returns 1 if the port is matched by the vector, 0 otherwise
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*/
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static __inline int
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port_match(u_short *portptr, int nports, u_short port, int range_flag)
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{
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if (!nports)
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return 1;
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if (range_flag) {
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if (portptr[0] <= port && port <= portptr[1]) {
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return 1;
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}
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nports -= 2;
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portptr += 2;
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}
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while (nports-- > 0) {
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if (*portptr++ == port) {
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return 1;
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}
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}
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return 0;
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}
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static int
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tcpflg_match(struct tcphdr *tcp, struct ip_fw *f)
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{
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u_char flg_set, flg_clr;
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if ((f->fw_tcpf & IP_FW_TCPF_ESTAB) &&
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(tcp->th_flags & (IP_FW_TCPF_RST | IP_FW_TCPF_ACK)))
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return 1;
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flg_set = tcp->th_flags & f->fw_tcpf;
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flg_clr = tcp->th_flags & f->fw_tcpnf;
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if (flg_set != f->fw_tcpf)
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return 0;
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if (flg_clr)
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return 0;
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return 1;
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}
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static int
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icmptype_match(struct icmp *icmp, struct ip_fw *f)
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{
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int type;
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if (!(f->fw_flg & IP_FW_F_ICMPBIT))
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return(1);
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type = icmp->icmp_type;
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/* check for matching type in the bitmap */
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if (type < IP_FW_ICMPTYPES_MAX &&
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(f->fw_uar.fw_icmptypes[type / (sizeof(unsigned) * NBBY)] &
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(1U << (type % (sizeof(unsigned) * NBBY)))))
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return(1);
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return(0); /* no match */
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}
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static int
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is_icmp_query(struct ip *ip)
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{
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const struct icmp *icmp;
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int icmp_type;
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icmp = (struct icmp *)((u_int32_t *)ip + ip->ip_hl);
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icmp_type = icmp->icmp_type;
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if (icmp_type == ICMP_ECHO || icmp_type == ICMP_ROUTERSOLICIT ||
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icmp_type == ICMP_TSTAMP || icmp_type == ICMP_IREQ ||
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icmp_type == ICMP_MASKREQ)
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return(1);
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return(0);
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}
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static int
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ipopts_match(struct ip *ip, struct ip_fw *f)
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{
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register u_char *cp;
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int opt, optlen, cnt;
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u_char opts, nopts, nopts_sve;
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cp = (u_char *)(ip + 1);
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cnt = (ip->ip_hl << 2) - sizeof (struct ip);
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opts = f->fw_ipopt;
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nopts = nopts_sve = f->fw_ipnopt;
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for (; cnt > 0; cnt -= optlen, cp += optlen) {
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opt = cp[IPOPT_OPTVAL];
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if (opt == IPOPT_EOL)
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break;
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if (opt == IPOPT_NOP)
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optlen = 1;
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else {
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optlen = cp[IPOPT_OLEN];
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if (optlen <= 0 || optlen > cnt) {
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return 0; /*XXX*/
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}
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}
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switch (opt) {
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default:
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break;
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case IPOPT_LSRR:
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opts &= ~IP_FW_IPOPT_LSRR;
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nopts &= ~IP_FW_IPOPT_LSRR;
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break;
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case IPOPT_SSRR:
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opts &= ~IP_FW_IPOPT_SSRR;
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nopts &= ~IP_FW_IPOPT_SSRR;
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break;
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case IPOPT_RR:
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opts &= ~IP_FW_IPOPT_RR;
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nopts &= ~IP_FW_IPOPT_RR;
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break;
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case IPOPT_TS:
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opts &= ~IP_FW_IPOPT_TS;
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nopts &= ~IP_FW_IPOPT_TS;
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break;
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}
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if (opts == nopts)
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break;
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}
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if (opts == 0 && nopts == nopts_sve)
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return 1;
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else
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return 0;
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}
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static __inline int
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iface_match(struct ifnet *ifp, union ip_fw_if *ifu, int byname)
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{
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/* Check by name or by IP address */
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if (byname) {
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/* Check unit number (-1 is wildcard) */
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if (ifu->fu_via_if.unit != -1
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&& ifp->if_unit != ifu->fu_via_if.unit)
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return(0);
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/* Check name */
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if (strncmp(ifp->if_name, ifu->fu_via_if.name, FW_IFNLEN))
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return(0);
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return(1);
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} else if (ifu->fu_via_ip.s_addr != 0) { /* Zero == wildcard */
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struct ifaddr *ia;
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for (ia = ifp->if_addrhead.tqh_first;
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ia != NULL; ia = ia->ifa_link.tqe_next) {
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if (ia->ifa_addr == NULL)
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continue;
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if (ia->ifa_addr->sa_family != AF_INET)
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continue;
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if (ifu->fu_via_ip.s_addr != ((struct sockaddr_in *)
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(ia->ifa_addr))->sin_addr.s_addr)
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continue;
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return(1);
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}
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return(0);
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}
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return(1);
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}
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static void
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ipfw_report(struct ip_fw *f, struct ip *ip,
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struct ifnet *rif, struct ifnet *oif)
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{
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if (ip) {
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struct tcphdr *const tcp = (struct tcphdr *) ((u_int32_t *) ip+ ip->ip_hl);
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struct udphdr *const udp = (struct udphdr *) ((u_int32_t *) ip+ ip->ip_hl);
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struct icmp *const icmp = (struct icmp *) ((u_int32_t *) ip + ip->ip_hl);
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u_int64_t count;
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char *action;
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char action2[32], proto[47], name[18], fragment[17];
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int len;
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count = f ? f->fw_pcnt : ++counter;
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if ((f == NULL && fw_verbose_limit != 0 && count > fw_verbose_limit) ||
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(f && f->fw_logamount != 0 && count > f->fw_loghighest))
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return;
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/* Print command name */
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snprintf(SNPARGS(name, 0), "ipfw: %d", f ? f->fw_number : -1);
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action = action2;
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if (!f)
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action = "Refuse";
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else {
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switch (f->fw_flg & IP_FW_F_COMMAND) {
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case IP_FW_F_DENY:
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action = "Deny";
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break;
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case IP_FW_F_REJECT:
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if (f->fw_reject_code == IP_FW_REJECT_RST)
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action = "Reset";
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else
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action = "Unreach";
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break;
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case IP_FW_F_ACCEPT:
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action = "Accept";
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break;
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case IP_FW_F_COUNT:
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action = "Count";
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break;
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#ifdef IPDIVERT
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case IP_FW_F_DIVERT:
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snprintf(SNPARGS(action2, 0), "Divert %d",
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f->fw_divert_port);
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break;
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case IP_FW_F_TEE:
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snprintf(SNPARGS(action2, 0), "Tee %d",
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f->fw_divert_port);
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break;
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#endif
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case IP_FW_F_SKIPTO:
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snprintf(SNPARGS(action2, 0), "SkipTo %d",
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f->fw_skipto_rule);
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break;
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#ifdef DUMMYNET
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case IP_FW_F_PIPE:
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snprintf(SNPARGS(action2, 0), "Pipe %d",
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f->fw_skipto_rule);
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break;
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#endif
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#ifdef IPFIREWALL_FORWARD
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case IP_FW_F_FWD:
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if (f->fw_fwd_ip.sin_port)
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snprintf(SNPARGS(action2, 0),
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"Forward to %s:%d",
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inet_ntoa(f->fw_fwd_ip.sin_addr),
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f->fw_fwd_ip.sin_port);
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else
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snprintf(SNPARGS(action2, 0), "Forward to %s",
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inet_ntoa(f->fw_fwd_ip.sin_addr));
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break;
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#endif
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default:
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action = "UNKNOWN";
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break;
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}
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}
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len = 0;
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switch (ip->ip_p) {
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case IPPROTO_TCP:
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len = snprintf(SNPARGS(proto, 0), "TCP %s",
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inet_ntoa(ip->ip_src));
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if ((ip->ip_off & IP_OFFMASK) == 0)
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len += snprintf(SNPARGS(proto, len), ":%d ",
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ntohs(tcp->th_sport));
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else
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len += snprintf(SNPARGS(proto, len), " ");
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len += snprintf(SNPARGS(proto, len), "%s",
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inet_ntoa(ip->ip_dst));
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if ((ip->ip_off & IP_OFFMASK) == 0)
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snprintf(SNPARGS(proto, len), ":%d",
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ntohs(tcp->th_dport));
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break;
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case IPPROTO_UDP:
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len = snprintf(SNPARGS(proto, 0), "UDP %s",
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inet_ntoa(ip->ip_src));
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if ((ip->ip_off & IP_OFFMASK) == 0)
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len += snprintf(SNPARGS(proto, len), ":%d ",
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ntohs(udp->uh_sport));
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else
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len += snprintf(SNPARGS(proto, len), " ");
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len += snprintf(SNPARGS(proto, len), "%s",
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inet_ntoa(ip->ip_dst));
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if ((ip->ip_off & IP_OFFMASK) == 0)
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snprintf(SNPARGS(proto, len), ":%d",
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ntohs(udp->uh_dport));
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break;
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case IPPROTO_ICMP:
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if ((ip->ip_off & IP_OFFMASK) == 0)
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len = snprintf(SNPARGS(proto, 0), "ICMP:%u.%u ",
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icmp->icmp_type, icmp->icmp_code);
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else
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len = snprintf(SNPARGS(proto, 0), "ICMP ");
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snprintf(SNPARGS(proto, len), "%s %s", inet_ntoa(ip->ip_src),
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inet_ntoa(ip->ip_dst));
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break;
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default:
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snprintf(SNPARGS(proto, 0), "P:%d %s %s", ip->ip_p,
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inet_ntoa(ip->ip_src), inet_ntoa(ip->ip_dst));
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break;
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}
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if ((ip->ip_off & IP_OFFMASK))
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snprintf(SNPARGS(fragment, 0), " Fragment = %d",
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ip->ip_off & IP_OFFMASK);
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else
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fragment[0] = '\0';
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if (oif)
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log(LOG_SECURITY | LOG_INFO, "%s %s %s out via %s%d%s\n",
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name, action, proto, oif->if_name, oif->if_unit, fragment);
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else if (rif)
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log(LOG_SECURITY | LOG_INFO, "%s %s %s in via %s%d%s\n", name,
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action, proto, rif->if_name, rif->if_unit, fragment);
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else
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log(LOG_SECURITY | LOG_INFO, "%s %s %s%s\n", name, action,
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proto, fragment);
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if ((f ? f->fw_logamount != 0 : 1) &&
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count == (f ? f->fw_loghighest : fw_verbose_limit))
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log(LOG_SECURITY | LOG_NOTICE,
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"ipfw: limit %d reached on entry %d\n",
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f ? f->fw_logamount : fw_verbose_limit,
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f ? f->fw_number : -1);
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}
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}
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|
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/*
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* given an ip_fw_chain *, lookup_next_rule will return a pointer
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* of the same type to the next one. This can be either the jump
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* target (for skipto instructions) or the next one in the chain (in
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* all other cases including a missing jump target).
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* Backward jumps are not allowed, so start looking from the next
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* rule...
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*/
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static struct ip_fw_chain * lookup_next_rule(struct ip_fw_chain *me);
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static struct ip_fw_chain *
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lookup_next_rule(struct ip_fw_chain *me)
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{
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struct ip_fw_chain *chain ;
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int rule = me->rule->fw_skipto_rule ; /* guess... */
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if ( (me->rule->fw_flg & IP_FW_F_COMMAND) == IP_FW_F_SKIPTO )
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for (chain = me->chain.le_next; chain ; chain = chain->chain.le_next )
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if (chain->rule->fw_number >= rule)
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return chain ;
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return me->chain.le_next ; /* failure or not a skipto */
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}
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|
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/*
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* Parameters:
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*
|
|
* pip Pointer to packet header (struct ip **)
|
|
* bridge_ipfw extension: pip = NULL means a complete ethernet packet
|
|
* including ethernet header in the mbuf. Other fields
|
|
* are ignored/invalid.
|
|
*
|
|
* hlen Packet header length
|
|
* oif Outgoing interface, or NULL if packet is incoming
|
|
* *cookie Skip up to the first rule past this rule number;
|
|
* *m The packet; we set to NULL when/if we nuke it.
|
|
* *flow_id pointer to the last matching rule (in/out)
|
|
* *next_hop socket we are forwarding to (in/out).
|
|
*
|
|
* Return value:
|
|
*
|
|
* 0 The packet is to be accepted and routed normally OR
|
|
* the packet was denied/rejected and has been dropped;
|
|
* in the latter case, *m is equal to NULL upon return.
|
|
* port Divert the packet to port.
|
|
*/
|
|
|
|
static int
|
|
ip_fw_chk(struct ip **pip, int hlen,
|
|
struct ifnet *oif, u_int16_t *cookie, struct mbuf **m,
|
|
struct ip_fw_chain **flow_id,
|
|
struct sockaddr_in **next_hop)
|
|
{
|
|
struct ip_fw_chain *chain;
|
|
struct ip_fw *rule = NULL;
|
|
struct ip *ip = NULL ;
|
|
struct ifnet *const rif = (*m)->m_pkthdr.rcvif;
|
|
u_short offset = 0 ;
|
|
u_short src_port, dst_port;
|
|
u_int16_t skipto = *cookie;
|
|
|
|
if (pip) { /* normal ip packet */
|
|
ip = *pip;
|
|
offset = (ip->ip_off & IP_OFFMASK);
|
|
} else { /* bridged or non-ip packet */
|
|
struct ether_header *eh = mtod(*m, struct ether_header *);
|
|
switch (ntohs(eh->ether_type)) {
|
|
case ETHERTYPE_IP :
|
|
if ((*m)->m_len<sizeof(struct ether_header) + sizeof(struct ip))
|
|
goto non_ip ;
|
|
ip = (struct ip *)(eh + 1 );
|
|
if (ip->ip_v != IPVERSION)
|
|
goto non_ip ;
|
|
hlen = ip->ip_hl << 2;
|
|
if (hlen < sizeof(struct ip)) /* minimum header length */
|
|
goto non_ip ;
|
|
if ((*m)->m_len < 14 + hlen + 14) {
|
|
printf("-- m_len %d, need more...\n", (*m)->m_len);
|
|
goto non_ip ;
|
|
}
|
|
offset = (ip->ip_off & IP_OFFMASK);
|
|
break ;
|
|
default :
|
|
non_ip: ip = NULL ;
|
|
break ;
|
|
}
|
|
}
|
|
|
|
if (*flow_id) {
|
|
if (fw_one_pass)
|
|
return 0 ; /* accept if passed first test */
|
|
/*
|
|
* pkt has already been tagged. Look for the next rule
|
|
* to restart processing
|
|
*/
|
|
chain = LIST_NEXT( *flow_id, chain);
|
|
|
|
if ( (chain = (*flow_id)->rule->next_rule_ptr) == NULL )
|
|
chain = (*flow_id)->rule->next_rule_ptr =
|
|
lookup_next_rule(*flow_id) ;
|
|
if (! chain) goto dropit;
|
|
} else {
|
|
/*
|
|
* Go down the chain, looking for enlightment
|
|
* If we've been asked to start at a given rule immediatly, do so.
|
|
*/
|
|
chain = LIST_FIRST(&ip_fw_chain);
|
|
if ( skipto ) {
|
|
if (skipto >= IPFW_DEFAULT_RULE)
|
|
goto dropit;
|
|
while (chain && (chain->rule->fw_number <= skipto)) {
|
|
chain = LIST_NEXT(chain, chain);
|
|
}
|
|
if (! chain) goto dropit;
|
|
}
|
|
}
|
|
*cookie = 0;
|
|
for (; chain; chain = LIST_NEXT(chain, chain)) {
|
|
register struct ip_fw * f ;
|
|
again:
|
|
f = chain->rule;
|
|
|
|
if (oif) {
|
|
/* Check direction outbound */
|
|
if (!(f->fw_flg & IP_FW_F_OUT))
|
|
continue;
|
|
} else {
|
|
/* Check direction inbound */
|
|
if (!(f->fw_flg & IP_FW_F_IN))
|
|
continue;
|
|
}
|
|
if (ip == NULL ) {
|
|
/*
|
|
* do relevant checks for non-ip packets:
|
|
* after this, only goto got_match or continue
|
|
*/
|
|
struct ether_header *eh = mtod(*m, struct ether_header *);
|
|
|
|
/*
|
|
* make default rule always match or we have a panic
|
|
*/
|
|
if (f->fw_number == IPFW_DEFAULT_RULE)
|
|
goto got_match ;
|
|
/*
|
|
* temporary hack:
|
|
* udp from 0.0.0.0 means this rule applies.
|
|
* 1 src port is match ether type
|
|
* 2 src ports (interval) is match ether type
|
|
* 3 src ports is match ether address
|
|
*/
|
|
if ( f->fw_src.s_addr != 0 || f->fw_prot != IPPROTO_UDP
|
|
|| f->fw_smsk.s_addr != 0xffffffff )
|
|
continue;
|
|
switch (IP_FW_GETNSRCP(f)) {
|
|
case 1: /* match one type */
|
|
if ( /* ( (f->fw_flg & IP_FW_F_INVSRC) != 0) ^ */
|
|
( f->fw_uar.fw_pts[0] == ntohs(eh->ether_type) ) ) {
|
|
goto got_match ;
|
|
}
|
|
break ;
|
|
default:
|
|
break ;
|
|
}
|
|
continue ;
|
|
}
|
|
|
|
/* Fragments */
|
|
if ((f->fw_flg & IP_FW_F_FRAG) && offset == 0 )
|
|
continue;
|
|
|
|
/* If src-addr doesn't match, not this rule. */
|
|
if (((f->fw_flg & IP_FW_F_INVSRC) != 0) ^ ((ip->ip_src.s_addr
|
|
& f->fw_smsk.s_addr) != f->fw_src.s_addr))
|
|
continue;
|
|
|
|
/* If dest-addr doesn't match, not this rule. */
|
|
if (((f->fw_flg & IP_FW_F_INVDST) != 0) ^ ((ip->ip_dst.s_addr
|
|
& f->fw_dmsk.s_addr) != f->fw_dst.s_addr))
|
|
continue;
|
|
|
|
/* Interface check */
|
|
if ((f->fw_flg & IF_FW_F_VIAHACK) == IF_FW_F_VIAHACK) {
|
|
struct ifnet *const iface = oif ? oif : rif;
|
|
|
|
/* Backwards compatibility hack for "via" */
|
|
if (!iface || !iface_match(iface,
|
|
&f->fw_in_if, f->fw_flg & IP_FW_F_OIFNAME))
|
|
continue;
|
|
} else {
|
|
/* Check receive interface */
|
|
if ((f->fw_flg & IP_FW_F_IIFACE)
|
|
&& (!rif || !iface_match(rif,
|
|
&f->fw_in_if, f->fw_flg & IP_FW_F_IIFNAME)))
|
|
continue;
|
|
/* Check outgoing interface */
|
|
if ((f->fw_flg & IP_FW_F_OIFACE)
|
|
&& (!oif || !iface_match(oif,
|
|
&f->fw_out_if, f->fw_flg & IP_FW_F_OIFNAME)))
|
|
continue;
|
|
}
|
|
|
|
/* Check IP options */
|
|
if (f->fw_ipopt != f->fw_ipnopt && !ipopts_match(ip, f))
|
|
continue;
|
|
|
|
/* Check protocol; if wildcard, and no [ug]id, match */
|
|
if (f->fw_prot == IPPROTO_IP) {
|
|
if (!(f->fw_flg & (IP_FW_F_UID|IP_FW_F_GID)))
|
|
goto rnd_then_got_match;
|
|
} else
|
|
/* If different, don't match */
|
|
if (ip->ip_p != f->fw_prot)
|
|
continue;
|
|
|
|
/*
|
|
* here, pip==NULL for bridged pkts -- they include the ethernet
|
|
* header so i have to adjust lengths accordingly
|
|
*/
|
|
#define PULLUP_TO(l) do { \
|
|
int len = (pip ? l : l + 14 ) ; \
|
|
if ((*m)->m_len < (len) ) { \
|
|
if ( (*m = m_pullup(*m, (len))) == 0) \
|
|
goto bogusfrag; \
|
|
ip = mtod(*m, struct ip *); \
|
|
if (pip) \
|
|
*pip = ip ; \
|
|
else \
|
|
ip = (struct ip *)((char *)ip + 14);\
|
|
offset = (ip->ip_off & IP_OFFMASK); \
|
|
} \
|
|
} while (0)
|
|
|
|
/* Protocol specific checks for uid only */
|
|
if (f->fw_flg & (IP_FW_F_UID|IP_FW_F_GID)) {
|
|
switch (ip->ip_p) {
|
|
case IPPROTO_TCP:
|
|
{
|
|
struct tcphdr *tcp;
|
|
struct inpcb *P;
|
|
|
|
if (offset == 1) /* cf. RFC 1858 */
|
|
goto bogusfrag;
|
|
if (offset != 0)
|
|
continue;
|
|
|
|
PULLUP_TO(hlen + 14);
|
|
tcp =(struct tcphdr *)((u_int32_t *)ip + ip->ip_hl);
|
|
|
|
if (oif)
|
|
P = in_pcblookup_hash(&tcbinfo, ip->ip_dst,
|
|
tcp->th_dport, ip->ip_src, tcp->th_sport, 0);
|
|
else
|
|
P = in_pcblookup_hash(&tcbinfo, ip->ip_src,
|
|
tcp->th_sport, ip->ip_dst, tcp->th_dport, 0);
|
|
|
|
if (P && P->inp_socket) {
|
|
if (f->fw_flg & IP_FW_F_UID) {
|
|
if (P->inp_socket->so_cred->cr_uid !=
|
|
f->fw_uid)
|
|
continue;
|
|
} else if (!groupmember(f->fw_gid,
|
|
P->inp_socket->so_cred))
|
|
continue;
|
|
} else continue;
|
|
|
|
break;
|
|
}
|
|
|
|
case IPPROTO_UDP:
|
|
{
|
|
struct udphdr *udp;
|
|
struct inpcb *P;
|
|
|
|
if (offset != 0)
|
|
continue;
|
|
|
|
PULLUP_TO(hlen + 4);
|
|
udp =(struct udphdr *)((u_int32_t *)ip + ip->ip_hl);
|
|
|
|
if (oif)
|
|
P = in_pcblookup_hash(&udbinfo, ip->ip_dst,
|
|
udp->uh_dport, ip->ip_src, udp->uh_sport, 1);
|
|
else
|
|
P = in_pcblookup_hash(&udbinfo, ip->ip_src,
|
|
udp->uh_sport, ip->ip_dst, udp->uh_dport, 1);
|
|
|
|
if (P && P->inp_socket) {
|
|
if (f->fw_flg & IP_FW_F_UID) {
|
|
if (P->inp_socket->so_cred->cr_uid !=
|
|
f->fw_uid)
|
|
continue;
|
|
} else if (!groupmember(f->fw_gid,
|
|
P->inp_socket->so_cred))
|
|
continue;
|
|
} else continue;
|
|
|
|
break;
|
|
}
|
|
|
|
default:
|
|
continue;
|
|
/*
|
|
* XXX Shouldn't GCC be allowing two bogusfrag labels if they're both inside
|
|
* separate blocks? Hmm.... It seems it's got incorrect behavior here.
|
|
*/
|
|
#if 0
|
|
bogusfrag:
|
|
if (fw_verbose)
|
|
ipfw_report(NULL, ip, rif, oif);
|
|
goto dropit;
|
|
#endif
|
|
}
|
|
}
|
|
|
|
/* Protocol specific checks */
|
|
switch (ip->ip_p) {
|
|
case IPPROTO_TCP:
|
|
{
|
|
struct tcphdr *tcp;
|
|
|
|
if (offset == 1) /* cf. RFC 1858 */
|
|
goto bogusfrag;
|
|
if (offset != 0) {
|
|
/*
|
|
* TCP flags and ports aren't available in this
|
|
* packet -- if this rule specified either one,
|
|
* we consider the rule a non-match.
|
|
*/
|
|
if (f->fw_nports != 0 ||
|
|
f->fw_tcpf != f->fw_tcpnf)
|
|
continue;
|
|
|
|
break;
|
|
}
|
|
PULLUP_TO(hlen + 14);
|
|
tcp = (struct tcphdr *) ((u_int32_t *)ip + ip->ip_hl);
|
|
if (f->fw_tcpf != f->fw_tcpnf && !tcpflg_match(tcp, f))
|
|
continue;
|
|
src_port = ntohs(tcp->th_sport);
|
|
dst_port = ntohs(tcp->th_dport);
|
|
goto check_ports;
|
|
}
|
|
|
|
case IPPROTO_UDP:
|
|
{
|
|
struct udphdr *udp;
|
|
|
|
if (offset != 0) {
|
|
/*
|
|
* Port specification is unavailable -- if this
|
|
* rule specifies a port, we consider the rule
|
|
* a non-match.
|
|
*/
|
|
if (f->fw_nports != 0)
|
|
continue;
|
|
|
|
break;
|
|
}
|
|
PULLUP_TO(hlen + 4);
|
|
udp = (struct udphdr *) ((u_int32_t *)ip + ip->ip_hl);
|
|
src_port = ntohs(udp->uh_sport);
|
|
dst_port = ntohs(udp->uh_dport);
|
|
check_ports:
|
|
if (!port_match(&f->fw_uar.fw_pts[0],
|
|
IP_FW_GETNSRCP(f), src_port,
|
|
f->fw_flg & IP_FW_F_SRNG))
|
|
continue;
|
|
if (!port_match(&f->fw_uar.fw_pts[IP_FW_GETNSRCP(f)],
|
|
IP_FW_GETNDSTP(f), dst_port,
|
|
f->fw_flg & IP_FW_F_DRNG))
|
|
continue;
|
|
break;
|
|
}
|
|
|
|
case IPPROTO_ICMP:
|
|
{
|
|
struct icmp *icmp;
|
|
|
|
if (offset != 0) /* Type isn't valid */
|
|
break;
|
|
PULLUP_TO(hlen + 2);
|
|
icmp = (struct icmp *) ((u_int32_t *)ip + ip->ip_hl);
|
|
if (!icmptype_match(icmp, f))
|
|
continue;
|
|
break;
|
|
}
|
|
#undef PULLUP_TO
|
|
|
|
bogusfrag:
|
|
if (fw_verbose)
|
|
ipfw_report(NULL, ip, rif, oif);
|
|
goto dropit;
|
|
}
|
|
|
|
rnd_then_got_match:
|
|
if ( ((struct ip_fw_ext *)f)->dont_match_prob &&
|
|
random() < ((struct ip_fw_ext *)f)->dont_match_prob )
|
|
continue ;
|
|
got_match:
|
|
*flow_id = chain ; /* XXX set flow id */
|
|
/* Update statistics */
|
|
f->fw_pcnt += 1;
|
|
if (ip) {
|
|
f->fw_bcnt += ip->ip_len;
|
|
}
|
|
f->timestamp = time_second;
|
|
|
|
/* Log to console if desired */
|
|
if ((f->fw_flg & IP_FW_F_PRN) && fw_verbose)
|
|
ipfw_report(f, ip, rif, oif);
|
|
|
|
/* Take appropriate action */
|
|
switch (f->fw_flg & IP_FW_F_COMMAND) {
|
|
case IP_FW_F_ACCEPT:
|
|
return(0);
|
|
case IP_FW_F_COUNT:
|
|
continue;
|
|
#ifdef IPDIVERT
|
|
case IP_FW_F_DIVERT:
|
|
*cookie = f->fw_number;
|
|
return(f->fw_divert_port);
|
|
case IP_FW_F_TEE:
|
|
/*
|
|
* XXX someday tee packet here, but beware that you
|
|
* can't use m_copym() or m_copypacket() because
|
|
* the divert input routine modifies the mbuf
|
|
* (and these routines only increment reference
|
|
* counts in the case of mbuf clusters), so need
|
|
* to write custom routine.
|
|
*/
|
|
continue;
|
|
#endif
|
|
case IP_FW_F_SKIPTO: /* XXX check */
|
|
if ( f->next_rule_ptr )
|
|
chain = f->next_rule_ptr ;
|
|
else
|
|
chain = lookup_next_rule(chain) ;
|
|
if (! chain) goto dropit;
|
|
goto again ;
|
|
#ifdef DUMMYNET
|
|
case IP_FW_F_PIPE:
|
|
return(f->fw_pipe_nr | 0x10000 );
|
|
#endif
|
|
#ifdef IPFIREWALL_FORWARD
|
|
case IP_FW_F_FWD:
|
|
/* Change the next-hop address for this packet.
|
|
* Initially we'll only worry about directly
|
|
* reachable next-hop's, but ultimately
|
|
* we will work out for next-hops that aren't
|
|
* direct the route we would take for it. We
|
|
* [cs]ould leave this latter problem to
|
|
* ip_output.c. We hope to high [name the abode of
|
|
* your favourite deity] that ip_output doesn't modify
|
|
* the new value of next_hop (which is dst there)
|
|
*/
|
|
if (next_hop != NULL) /* Make sure, first... */
|
|
*next_hop = &(f->fw_fwd_ip);
|
|
return(0); /* Allow the packet */
|
|
#endif
|
|
}
|
|
|
|
/* Deny/reject this packet using this rule */
|
|
rule = f;
|
|
break;
|
|
|
|
}
|
|
|
|
#ifdef DIAGNOSTIC
|
|
/* Rule IPFW_DEFAULT_RULE should always be there and should always match */
|
|
if (!chain)
|
|
panic("ip_fw: chain");
|
|
#endif
|
|
|
|
/*
|
|
* At this point, we're going to drop the packet.
|
|
* Send a reject notice if all of the following are true:
|
|
*
|
|
* - The packet matched a reject rule
|
|
* - The packet is not an ICMP packet, or is an ICMP query packet
|
|
* - The packet is not a multicast or broadcast packet
|
|
*/
|
|
if ((rule->fw_flg & IP_FW_F_COMMAND) == IP_FW_F_REJECT
|
|
&& ip
|
|
&& (ip->ip_p != IPPROTO_ICMP || is_icmp_query(ip))
|
|
&& !((*m)->m_flags & (M_BCAST|M_MCAST))
|
|
&& !IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
|
|
switch (rule->fw_reject_code) {
|
|
case IP_FW_REJECT_RST:
|
|
{
|
|
struct tcphdr *const tcp =
|
|
(struct tcphdr *) ((u_int32_t *)ip + ip->ip_hl);
|
|
struct tcpiphdr ti, *const tip = (struct tcpiphdr *) ip;
|
|
|
|
if (offset != 0 || (tcp->th_flags & TH_RST))
|
|
break;
|
|
ti.ti_i = *((struct ipovly *) ip);
|
|
ti.ti_t = *tcp;
|
|
bcopy(&ti, ip, sizeof(ti));
|
|
NTOHL(tip->ti_seq);
|
|
NTOHL(tip->ti_ack);
|
|
tip->ti_len = ip->ip_len - hlen - (tip->ti_off << 2);
|
|
if (tcp->th_flags & TH_ACK) {
|
|
tcp_respond(NULL, tip, *m,
|
|
(tcp_seq)0, ntohl(tcp->th_ack), TH_RST);
|
|
} else {
|
|
if (tcp->th_flags & TH_SYN)
|
|
tip->ti_len++;
|
|
tcp_respond(NULL, tip, *m, tip->ti_seq
|
|
+ tip->ti_len, (tcp_seq)0, TH_RST|TH_ACK);
|
|
}
|
|
*m = NULL;
|
|
break;
|
|
}
|
|
default: /* Send an ICMP unreachable using code */
|
|
icmp_error(*m, ICMP_UNREACH,
|
|
rule->fw_reject_code, 0L, 0);
|
|
*m = NULL;
|
|
break;
|
|
}
|
|
}
|
|
|
|
dropit:
|
|
/*
|
|
* Finally, drop the packet.
|
|
*/
|
|
/* *cookie = 0; */ /* XXX is this necessary ? */
|
|
if (*m) {
|
|
m_freem(*m);
|
|
*m = NULL;
|
|
}
|
|
return(0);
|
|
}
|
|
|
|
/*
|
|
* when a rule is added/deleted, zero the direct pointers within
|
|
* all firewall rules. These will be reconstructed on the fly
|
|
* as packets are matched.
|
|
* Must be called at splnet().
|
|
*/
|
|
static void
|
|
flush_rule_ptrs()
|
|
{
|
|
struct ip_fw_chain *fcp ;
|
|
|
|
for (fcp = ip_fw_chain.lh_first; fcp; fcp = fcp->chain.le_next) {
|
|
fcp->rule->next_rule_ptr = NULL ;
|
|
}
|
|
}
|
|
|
|
static int
|
|
add_entry(struct ip_fw_head *chainptr, struct ip_fw *frwl)
|
|
{
|
|
struct ip_fw *ftmp = 0;
|
|
struct ip_fw_ext *ftmp_ext = 0 ;
|
|
struct ip_fw_chain *fwc = 0, *fcp, *fcpl = 0;
|
|
u_short nbr = 0;
|
|
int s;
|
|
|
|
fwc = malloc(sizeof *fwc, M_IPFW, M_DONTWAIT);
|
|
ftmp_ext = malloc(sizeof *ftmp_ext, M_IPFW, M_DONTWAIT);
|
|
ftmp = &ftmp_ext->rule ;
|
|
if (!fwc || !ftmp) {
|
|
dprintf(("%s malloc said no\n", err_prefix));
|
|
if (fwc) free(fwc, M_IPFW);
|
|
if (ftmp) free(ftmp, M_IPFW);
|
|
return (ENOSPC);
|
|
}
|
|
|
|
bzero(ftmp_ext, sizeof(*ftmp_ext)); /* play safe! */
|
|
bcopy(frwl, ftmp, sizeof(*ftmp));
|
|
if (ftmp->fw_flg & IP_FW_F_RND_MATCH)
|
|
ftmp_ext->dont_match_prob = (intptr_t)ftmp->pipe_ptr;
|
|
|
|
ftmp->fw_in_if.fu_via_if.name[FW_IFNLEN - 1] = '\0';
|
|
ftmp->fw_pcnt = 0L;
|
|
ftmp->fw_bcnt = 0L;
|
|
ftmp->next_rule_ptr = NULL ;
|
|
ftmp->pipe_ptr = NULL ;
|
|
fwc->rule = ftmp;
|
|
|
|
s = splnet();
|
|
|
|
if (chainptr->lh_first == 0) {
|
|
LIST_INSERT_HEAD(chainptr, fwc, chain);
|
|
splx(s);
|
|
return(0);
|
|
}
|
|
|
|
/* If entry number is 0, find highest numbered rule and add 100 */
|
|
if (ftmp->fw_number == 0) {
|
|
for (fcp = LIST_FIRST(chainptr); fcp; fcp = LIST_NEXT(fcp, chain)) {
|
|
if (fcp->rule->fw_number != (u_short)-1)
|
|
nbr = fcp->rule->fw_number;
|
|
else
|
|
break;
|
|
}
|
|
if (nbr < IPFW_DEFAULT_RULE - 100)
|
|
nbr += 100;
|
|
ftmp->fw_number = nbr;
|
|
}
|
|
|
|
/* Got a valid number; now insert it, keeping the list ordered */
|
|
for (fcp = LIST_FIRST(chainptr); fcp; fcp = LIST_NEXT(fcp, chain)) {
|
|
if (fcp->rule->fw_number > ftmp->fw_number) {
|
|
if (fcpl) {
|
|
LIST_INSERT_AFTER(fcpl, fwc, chain);
|
|
} else {
|
|
LIST_INSERT_HEAD(chainptr, fwc, chain);
|
|
}
|
|
break;
|
|
} else {
|
|
fcpl = fcp;
|
|
}
|
|
}
|
|
flush_rule_ptrs();
|
|
|
|
splx(s);
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
del_entry(struct ip_fw_head *chainptr, u_short number)
|
|
{
|
|
struct ip_fw_chain *fcp;
|
|
|
|
fcp = LIST_FIRST(chainptr);
|
|
if (number != (u_short)-1) {
|
|
for (; fcp; fcp = LIST_NEXT(fcp, chain)) {
|
|
if (fcp->rule->fw_number == number) {
|
|
int s;
|
|
|
|
/* prevent access to rules while removing them */
|
|
s = splnet();
|
|
while (fcp && fcp->rule->fw_number == number) {
|
|
struct ip_fw_chain *next;
|
|
|
|
next = LIST_NEXT(fcp, chain);
|
|
LIST_REMOVE(fcp, chain);
|
|
#ifdef DUMMYNET
|
|
dn_rule_delete(fcp) ;
|
|
#endif
|
|
flush_rule_ptrs();
|
|
free(fcp->rule, M_IPFW);
|
|
free(fcp, M_IPFW);
|
|
fcp = next;
|
|
}
|
|
splx(s);
|
|
return 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
return (EINVAL);
|
|
}
|
|
|
|
static int
|
|
zero_entry(struct ip_fw *frwl)
|
|
{
|
|
struct ip_fw_chain *fcp;
|
|
int s, cleared;
|
|
|
|
if (frwl == 0) {
|
|
s = splnet();
|
|
for (fcp = LIST_FIRST(&ip_fw_chain); fcp; fcp = LIST_NEXT(fcp, chain)) {
|
|
fcp->rule->fw_bcnt = fcp->rule->fw_pcnt = 0;
|
|
fcp->rule->fw_loghighest = fcp->rule->fw_logamount;
|
|
fcp->rule->timestamp = 0;
|
|
}
|
|
splx(s);
|
|
}
|
|
else {
|
|
cleared = 0;
|
|
|
|
/*
|
|
* It's possible to insert multiple chain entries with the
|
|
* same number, so we don't stop after finding the first
|
|
* match if zeroing a specific entry.
|
|
*/
|
|
for (fcp = LIST_FIRST(&ip_fw_chain); fcp; fcp = LIST_NEXT(fcp, chain))
|
|
if (frwl->fw_number == fcp->rule->fw_number) {
|
|
s = splnet();
|
|
while (fcp && frwl->fw_number == fcp->rule->fw_number) {
|
|
fcp->rule->fw_bcnt = fcp->rule->fw_pcnt = 0;
|
|
fcp->rule->fw_loghighest =
|
|
fcp->rule->fw_logamount;
|
|
fcp->rule->timestamp = 0;
|
|
fcp = LIST_NEXT(fcp, chain);
|
|
}
|
|
splx(s);
|
|
cleared = 1;
|
|
break;
|
|
}
|
|
if (!cleared) /* we didn't find any matching rules */
|
|
return (EINVAL);
|
|
}
|
|
|
|
if (fw_verbose) {
|
|
if (frwl)
|
|
log(LOG_SECURITY | LOG_NOTICE,
|
|
"ipfw: Entry %d cleared.\n", frwl->fw_number);
|
|
else
|
|
log(LOG_SECURITY | LOG_NOTICE,
|
|
"ipfw: Accounting cleared.\n");
|
|
}
|
|
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
resetlog_entry(struct ip_fw *frwl)
|
|
{
|
|
struct ip_fw_chain *fcp;
|
|
int s, cleared;
|
|
|
|
if (frwl == 0) {
|
|
s = splnet();
|
|
counter = 0;
|
|
for (fcp = LIST_FIRST(&ip_fw_chain); fcp; fcp = LIST_NEXT(fcp, chain))
|
|
fcp->rule->fw_loghighest = fcp->rule->fw_pcnt +
|
|
fcp->rule->fw_logamount;
|
|
splx(s);
|
|
}
|
|
else {
|
|
cleared = 0;
|
|
|
|
/*
|
|
* It's possible to insert multiple chain entries with the
|
|
* same number, so we don't stop after finding the first
|
|
* match if zeroing a specific entry.
|
|
*/
|
|
for (fcp = LIST_FIRST(&ip_fw_chain); fcp; fcp = LIST_NEXT(fcp, chain))
|
|
if (frwl->fw_number == fcp->rule->fw_number) {
|
|
s = splnet();
|
|
while (fcp && frwl->fw_number == fcp->rule->fw_number) {
|
|
fcp->rule->fw_loghighest =
|
|
fcp->rule->fw_pcnt +
|
|
fcp->rule->fw_logamount;
|
|
fcp = LIST_NEXT(fcp, chain);
|
|
}
|
|
splx(s);
|
|
cleared = 1;
|
|
break;
|
|
}
|
|
if (!cleared) /* we didn't find any matching rules */
|
|
return (EINVAL);
|
|
}
|
|
|
|
if (fw_verbose) {
|
|
if (frwl)
|
|
log(LOG_SECURITY | LOG_NOTICE,
|
|
"ipfw: Entry %d logging count reset.\n",
|
|
frwl->fw_number);
|
|
else
|
|
log(LOG_SECURITY | LOG_NOTICE, "
|
|
ipfw: All logging counts cleared.\n");
|
|
}
|
|
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
check_ipfw_struct(struct ip_fw *frwl)
|
|
{
|
|
/* Check for invalid flag bits */
|
|
if ((frwl->fw_flg & ~IP_FW_F_MASK) != 0) {
|
|
dprintf(("%s undefined flag bits set (flags=%x)\n",
|
|
err_prefix, frwl->fw_flg));
|
|
return (EINVAL);
|
|
}
|
|
/* Must apply to incoming or outgoing (or both) */
|
|
if (!(frwl->fw_flg & (IP_FW_F_IN | IP_FW_F_OUT))) {
|
|
dprintf(("%s neither in nor out\n", err_prefix));
|
|
return (EINVAL);
|
|
}
|
|
/* Empty interface name is no good */
|
|
if (((frwl->fw_flg & IP_FW_F_IIFNAME)
|
|
&& !*frwl->fw_in_if.fu_via_if.name)
|
|
|| ((frwl->fw_flg & IP_FW_F_OIFNAME)
|
|
&& !*frwl->fw_out_if.fu_via_if.name)) {
|
|
dprintf(("%s empty interface name\n", err_prefix));
|
|
return (EINVAL);
|
|
}
|
|
/* Sanity check interface matching */
|
|
if ((frwl->fw_flg & IF_FW_F_VIAHACK) == IF_FW_F_VIAHACK) {
|
|
; /* allow "via" backwards compatibility */
|
|
} else if ((frwl->fw_flg & IP_FW_F_IN)
|
|
&& (frwl->fw_flg & IP_FW_F_OIFACE)) {
|
|
dprintf(("%s outgoing interface check on incoming\n",
|
|
err_prefix));
|
|
return (EINVAL);
|
|
}
|
|
/* Sanity check port ranges */
|
|
if ((frwl->fw_flg & IP_FW_F_SRNG) && IP_FW_GETNSRCP(frwl) < 2) {
|
|
dprintf(("%s src range set but n_src_p=%d\n",
|
|
err_prefix, IP_FW_GETNSRCP(frwl)));
|
|
return (EINVAL);
|
|
}
|
|
if ((frwl->fw_flg & IP_FW_F_DRNG) && IP_FW_GETNDSTP(frwl) < 2) {
|
|
dprintf(("%s dst range set but n_dst_p=%d\n",
|
|
err_prefix, IP_FW_GETNDSTP(frwl)));
|
|
return (EINVAL);
|
|
}
|
|
if (IP_FW_GETNSRCP(frwl) + IP_FW_GETNDSTP(frwl) > IP_FW_MAX_PORTS) {
|
|
dprintf(("%s too many ports (%d+%d)\n",
|
|
err_prefix, IP_FW_GETNSRCP(frwl), IP_FW_GETNDSTP(frwl)));
|
|
return (EINVAL);
|
|
}
|
|
/*
|
|
* Protocols other than TCP/UDP don't use port range
|
|
*/
|
|
if ((frwl->fw_prot != IPPROTO_TCP) &&
|
|
(frwl->fw_prot != IPPROTO_UDP) &&
|
|
(IP_FW_GETNSRCP(frwl) || IP_FW_GETNDSTP(frwl))) {
|
|
dprintf(("%s port(s) specified for non TCP/UDP rule\n",
|
|
err_prefix));
|
|
return (EINVAL);
|
|
}
|
|
|
|
/*
|
|
* Rather than modify the entry to make such entries work,
|
|
* we reject this rule and require user level utilities
|
|
* to enforce whatever policy they deem appropriate.
|
|
*/
|
|
if ((frwl->fw_src.s_addr & (~frwl->fw_smsk.s_addr)) ||
|
|
(frwl->fw_dst.s_addr & (~frwl->fw_dmsk.s_addr))) {
|
|
dprintf(("%s rule never matches\n", err_prefix));
|
|
return (EINVAL);
|
|
}
|
|
|
|
if ((frwl->fw_flg & IP_FW_F_FRAG) &&
|
|
(frwl->fw_prot == IPPROTO_UDP || frwl->fw_prot == IPPROTO_TCP)) {
|
|
if (frwl->fw_nports) {
|
|
dprintf(("%s cannot mix 'frag' and ports\n", err_prefix));
|
|
return (EINVAL);
|
|
}
|
|
if (frwl->fw_prot == IPPROTO_TCP &&
|
|
frwl->fw_tcpf != frwl->fw_tcpnf) {
|
|
dprintf(("%s cannot mix 'frag' and TCP flags\n", err_prefix));
|
|
return (EINVAL);
|
|
}
|
|
}
|
|
|
|
/* Check command specific stuff */
|
|
switch (frwl->fw_flg & IP_FW_F_COMMAND)
|
|
{
|
|
case IP_FW_F_REJECT:
|
|
if (frwl->fw_reject_code >= 0x100
|
|
&& !(frwl->fw_prot == IPPROTO_TCP
|
|
&& frwl->fw_reject_code == IP_FW_REJECT_RST)) {
|
|
dprintf(("%s unknown reject code\n", err_prefix));
|
|
return (EINVAL);
|
|
}
|
|
break;
|
|
#if defined(IPDIVERT) || defined(DUMMYNET)
|
|
#ifdef IPDIVERT
|
|
case IP_FW_F_DIVERT: /* Diverting to port zero is invalid */
|
|
case IP_FW_F_TEE:
|
|
#endif
|
|
#ifdef DUMMYNET
|
|
case IP_FW_F_PIPE: /* piping through 0 is invalid */
|
|
#endif
|
|
if (frwl->fw_divert_port == 0) {
|
|
dprintf(("%s can't divert to port 0\n", err_prefix));
|
|
return (EINVAL);
|
|
}
|
|
break;
|
|
#endif /* IPDIVERT || DUMMYNET */
|
|
case IP_FW_F_DENY:
|
|
case IP_FW_F_ACCEPT:
|
|
case IP_FW_F_COUNT:
|
|
case IP_FW_F_SKIPTO:
|
|
#ifdef IPFIREWALL_FORWARD
|
|
case IP_FW_F_FWD:
|
|
#endif
|
|
case IP_FW_F_UID:
|
|
case IP_FW_F_GID:
|
|
break;
|
|
default:
|
|
dprintf(("%s invalid command\n", err_prefix));
|
|
return (EINVAL);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
ip_fw_ctl(struct sockopt *sopt)
|
|
{
|
|
int error, s;
|
|
size_t size;
|
|
struct ip_fw_chain *fcp;
|
|
struct ip_fw frwl, *bp , *buf;
|
|
|
|
/*
|
|
* Disallow sets in really-really secure mode, but still allow
|
|
* the logging counters to be reset.
|
|
*/
|
|
if (sopt->sopt_dir == SOPT_SET && securelevel >= 3 &&
|
|
sopt->sopt_name != IP_FW_RESETLOG)
|
|
return (EPERM);
|
|
error = 0;
|
|
|
|
switch (sopt->sopt_name) {
|
|
case IP_FW_GET:
|
|
for (fcp = LIST_FIRST(&ip_fw_chain), size = 0; fcp;
|
|
fcp = LIST_NEXT(fcp, chain))
|
|
size += sizeof *fcp->rule;
|
|
buf = malloc(size, M_TEMP, M_WAITOK);
|
|
if (buf == 0) {
|
|
error = ENOBUFS;
|
|
break;
|
|
}
|
|
|
|
for (fcp = LIST_FIRST(&ip_fw_chain), bp = buf; fcp;
|
|
fcp = LIST_NEXT(fcp, chain)) {
|
|
bcopy(fcp->rule, bp, sizeof *fcp->rule);
|
|
bp->pipe_ptr = (void *)(intptr_t)
|
|
((struct ip_fw_ext *)fcp->rule)->dont_match_prob;
|
|
bp++;
|
|
}
|
|
error = sooptcopyout(sopt, buf, size);
|
|
FREE(buf, M_TEMP);
|
|
break;
|
|
|
|
case IP_FW_FLUSH:
|
|
for (fcp = ip_fw_chain.lh_first;
|
|
fcp != 0 && fcp->rule->fw_number != IPFW_DEFAULT_RULE;
|
|
fcp = ip_fw_chain.lh_first) {
|
|
s = splnet();
|
|
LIST_REMOVE(fcp, chain);
|
|
#ifdef DUMMYNET
|
|
dn_rule_delete(fcp);
|
|
#endif
|
|
FREE(fcp->rule, M_IPFW);
|
|
FREE(fcp, M_IPFW);
|
|
splx(s);
|
|
}
|
|
break;
|
|
|
|
case IP_FW_ZERO:
|
|
if (sopt->sopt_val != 0) {
|
|
error = sooptcopyin(sopt, &frwl, sizeof frwl,
|
|
sizeof frwl);
|
|
if (error || (error = zero_entry(&frwl)))
|
|
break;
|
|
} else {
|
|
error = zero_entry(0);
|
|
}
|
|
break;
|
|
|
|
case IP_FW_ADD:
|
|
error = sooptcopyin(sopt, &frwl, sizeof frwl, sizeof frwl);
|
|
if (error || (error = check_ipfw_struct(&frwl)))
|
|
break;
|
|
|
|
if (frwl.fw_number == IPFW_DEFAULT_RULE) {
|
|
dprintf(("%s can't add rule %u\n", err_prefix,
|
|
(unsigned)IPFW_DEFAULT_RULE));
|
|
error = EINVAL;
|
|
} else {
|
|
error = add_entry(&ip_fw_chain, &frwl);
|
|
}
|
|
break;
|
|
|
|
case IP_FW_DEL:
|
|
error = sooptcopyin(sopt, &frwl, sizeof frwl, sizeof frwl);
|
|
if (error)
|
|
break;
|
|
|
|
if (frwl.fw_number == IPFW_DEFAULT_RULE) {
|
|
dprintf(("%s can't delete rule %u\n", err_prefix,
|
|
(unsigned)IPFW_DEFAULT_RULE));
|
|
error = EINVAL;
|
|
} else {
|
|
error = del_entry(&ip_fw_chain, frwl.fw_number);
|
|
}
|
|
break;
|
|
|
|
case IP_FW_RESETLOG:
|
|
if (sopt->sopt_val != 0) {
|
|
error = sooptcopyin(sopt, &frwl, sizeof frwl,
|
|
sizeof frwl);
|
|
if (error || (error = resetlog_entry(&frwl)))
|
|
break;
|
|
} else {
|
|
error = resetlog_entry(0);
|
|
}
|
|
break;
|
|
|
|
default:
|
|
printf("ip_fw_ctl invalid option %d\n", sopt->sopt_name);
|
|
error = EINVAL ;
|
|
}
|
|
|
|
return (error);
|
|
}
|
|
|
|
struct ip_fw_chain *ip_fw_default_rule ;
|
|
|
|
void
|
|
ip_fw_init(void)
|
|
{
|
|
struct ip_fw default_rule;
|
|
|
|
ip_fw_chk_ptr = ip_fw_chk;
|
|
ip_fw_ctl_ptr = ip_fw_ctl;
|
|
LIST_INIT(&ip_fw_chain);
|
|
|
|
bzero(&default_rule, sizeof default_rule);
|
|
default_rule.fw_prot = IPPROTO_IP;
|
|
default_rule.fw_number = IPFW_DEFAULT_RULE;
|
|
#ifdef IPFIREWALL_DEFAULT_TO_ACCEPT
|
|
default_rule.fw_flg |= IP_FW_F_ACCEPT;
|
|
#else
|
|
default_rule.fw_flg |= IP_FW_F_DENY;
|
|
#endif
|
|
default_rule.fw_flg |= IP_FW_F_IN | IP_FW_F_OUT;
|
|
if (check_ipfw_struct(&default_rule) != 0 ||
|
|
add_entry(&ip_fw_chain, &default_rule))
|
|
panic("ip_fw_init");
|
|
|
|
ip_fw_default_rule = ip_fw_chain.lh_first ;
|
|
printf("IP packet filtering initialized, "
|
|
#ifdef IPDIVERT
|
|
"divert enabled, ");
|
|
#else
|
|
"divert disabled, ");
|
|
#endif
|
|
#ifdef IPFIREWALL_FORWARD
|
|
printf("rule-based forwarding enabled, ");
|
|
#else
|
|
printf("rule-based forwarding disabled, ");
|
|
#endif
|
|
#ifdef IPFIREWALL_DEFAULT_TO_ACCEPT
|
|
printf("default to accept, ");
|
|
#endif
|
|
#ifndef IPFIREWALL_VERBOSE
|
|
printf("logging disabled\n");
|
|
#else
|
|
if (fw_verbose_limit == 0)
|
|
printf("unlimited logging\n");
|
|
else
|
|
printf("logging limited to %d packets/entry by default\n",
|
|
fw_verbose_limit);
|
|
#endif
|
|
}
|
|
|
|
static ip_fw_chk_t *old_chk_ptr;
|
|
static ip_fw_ctl_t *old_ctl_ptr;
|
|
|
|
static int
|
|
ipfw_modevent(module_t mod, int type, void *unused)
|
|
{
|
|
int s;
|
|
|
|
switch (type) {
|
|
case MOD_LOAD:
|
|
s = splnet();
|
|
|
|
old_chk_ptr = ip_fw_chk_ptr;
|
|
old_ctl_ptr = ip_fw_ctl_ptr;
|
|
|
|
ip_fw_init();
|
|
splx(s);
|
|
return 0;
|
|
case MOD_UNLOAD:
|
|
s = splnet();
|
|
|
|
ip_fw_chk_ptr = old_chk_ptr;
|
|
ip_fw_ctl_ptr = old_ctl_ptr;
|
|
|
|
while (LIST_FIRST(&ip_fw_chain) != NULL) {
|
|
struct ip_fw_chain *fcp = LIST_FIRST(&ip_fw_chain);
|
|
LIST_REMOVE(LIST_FIRST(&ip_fw_chain), chain);
|
|
free(fcp->rule, M_IPFW);
|
|
free(fcp, M_IPFW);
|
|
}
|
|
|
|
splx(s);
|
|
return 0;
|
|
default:
|
|
break;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static moduledata_t ipfwmod = {
|
|
"ipfw",
|
|
ipfw_modevent,
|
|
0
|
|
};
|
|
DECLARE_MODULE(ipfw, ipfwmod, SI_SUB_PSEUDO, SI_ORDER_ANY);
|