/* * Copyright (c) 1994 Ugen J.S.Antsilevich * Idea and grammar partially left from: * Copyright (c) 1993 Daniel Boulet * * Redistribution and use in source forms, with and without modification, * are permitted provided that this entire comment appears intact. * * Redistribution in binary form may occur without any restrictions. * Obviously, it would be nice if you gave credit where credit is due * but requiring it would be too onerous. * * This software is provided ``AS IS'' without any warranties of any kind. * * NEW command line interface for IP firewall facility */ #include #include #include #include #include #include #include #include #include #include #include #include #include #define IPFIREWALL #define IPACCT #include #define MAXSTR 25 char progname[MAXSTR]; /* Program name for errors */ char proto_name[MAXSTR]=""; /* Current line protocol */ int s; /* main RAW socket */ int do_resolv=1; /* Would try to resolv all */ int do_verbose=0; /* Verbose output(differs) */ int ports_ok=0; /* flag allowing ports */ u_short flags=0; /* New entry flags */ #define FW 1 /* Firewall action */ #define AC 2 /* Accounting action */ #define S_SEP1 "f" /* of "from" */ #define S_SEP2 "t" /* of "to" */ #define P_AC "a" /* of "accept" for policy action */ #define P_DE "d" /* of "deny" for policy action */ #define CH_FW "f" /* of "firewall" for chains in zero/flush */ #define CH_AC "a" /* of "accounting" for chain in zero/flush/list */ #define CH_BLK "b" /* of "blocking" for chain in list */ #define CH_FWD "f" /* of "forwarding" for chain in list */ char action_tab[][MAXSTR]={ "addb", #define A_ADDB 0 "delb", #define A_DELB 1 "chkb", #define A_CHKB 2 "addf", #define A_ADDF 3 "delf", #define A_DELF 4 "chkf", #define A_CHKF 5 "adda", #define A_ADDA 6 "dela", #define A_DELA 7 "f", #define A_FLUSH 8 "z", #define A_ZERO 9 "l", #define A_LIST 10 "p", #define A_POLICY 11 "", #define A_NONE 12 }; char type_tab[][MAXSTR]={ "ac", #define T_ACCEPT 0 "de", #define T_DENY 1 "si", #define T_SINGLE 2 "bi", #define T_BIDIR 3 "", #define T_NONE 4 }; char proto_tab[][MAXSTR]={ "all", #define P_ALL 0 "icmp", #define P_ICMP 1 "tcp", #define P_TCP 2 "udp", #define P_UDP 3 "" #define P_NONE 4 }; struct nlist nlf[]={ #define N_BCHAIN 0 { "_ip_fw_blk_chain" }, #define N_FCHAIN 1 { "_ip_fw_fwd_chain" }, #define N_POLICY 2 { "_ip_fw_policy" }, "" , }; struct nlist nla[]={ #define N_ACHAIN 0 { "_ip_acct_chain" }, "" , }; int mask_bits(m_ad) struct in_addr m_ad; { int h_fnd=0,h_num=0,i; u_long mask; mask=ntohl(m_ad.s_addr); for (i=0;i>1; } return h_num; } void show_ipfw(chain,c_t) struct ip_fw *chain; int c_t; { char *comma; u_long adrt; struct hostent *he; int i,mb; if (do_verbose) { printf("%8d:%8d ",chain->b_cnt,chain->p_cnt); } if (do_verbose) if (c_t==FW) { if (chain->flags & IP_FW_F_ACCEPT) printf("A"); else printf("D"); } else { if (chain->flags & IP_FW_F_BIDIR) printf("B"); else printf("S"); } else if (c_t==FW) { if (chain->flags & IP_FW_F_ACCEPT) printf("accept "); else printf("deny "); } else { if (chain->flags & IP_FW_F_BIDIR) printf("bidir "); else printf("single "); } if (do_verbose) switch (chain->flags & IP_FW_F_KIND) { case IP_FW_F_ICMP: printf("I "); break; case IP_FW_F_TCP: printf("T "); break; case IP_FW_F_UDP: printf("U "); break; case IP_FW_F_ALL: printf("A "); break; default: break; } else switch (chain->flags & IP_FW_F_KIND) { case IP_FW_F_ICMP: printf("icmp "); break; case IP_FW_F_TCP: printf("tcp "); break; case IP_FW_F_UDP: printf("udp "); break; case IP_FW_F_ALL: printf("all "); break; default: break; } if (do_verbose) printf("["); else printf("from "); adrt=ntohl(chain->src_mask.s_addr); if (adrt==ULONG_MAX && do_resolv) { adrt=(chain->src.s_addr); he=gethostbyaddr((char *)&adrt,sizeof(u_long),AF_INET); if (he==NULL) { printf(inet_ntoa(chain->src)); printf(":"); printf(inet_ntoa(chain->src_mask)); } else printf("%s",he->h_name); } else { printf(inet_ntoa(chain->src)); if (adrt!=ULONG_MAX) if ((mb=mask_bits(chain->src_mask))>=0) printf("/%d",mb); else { printf(":"); printf(inet_ntoa(chain->src_mask)); } } comma = " "; for (i=0;in_src_p; i++ ) { printf("%s%d",comma,chain->ports[i]); if (i==0 && (chain->flags & IP_FW_F_SRNG)) comma = ":"; else comma = ","; } if (do_verbose) printf("]["); else printf(" to "); adrt=ntohl(chain->dst_mask.s_addr); if (adrt==ULONG_MAX && do_resolv) { adrt=(chain->dst.s_addr); he=gethostbyaddr((char *)&adrt,sizeof(u_long),AF_INET); if (he==NULL) { printf(inet_ntoa(chain->dst)); printf(":"); printf(inet_ntoa(chain->dst_mask)); } else printf("%s",he->h_name); } else { printf(inet_ntoa(chain->dst)); if (adrt!=ULONG_MAX) if ((mb=mask_bits(chain->dst_mask))>=0) printf("/%d",mb); else { printf(":"); printf(inet_ntoa(chain->dst_mask)); } } comma = " "; for (i=0;in_dst_p;i++) { printf("%s%d",comma,chain->ports[chain->n_src_p+i]); if (i==chain->n_src_p && (chain->flags & IP_FW_F_DRNG)) comma = ":"; else comma = ","; } if (do_verbose) printf("]\n"); else printf("\n"); } list(av) char **av; { kvm_t *kd; static char errb[_POSIX2_LINE_MAX]; struct ip_fw b,*btmp; if (!(kd=kvm_openfiles(NULL,NULL,NULL,O_RDONLY,errb))) { fprintf(stderr,"%s: kvm_openfiles: %s\n", progname,kvm_geterr(kd)); exit(1); } if (*av==NULL || !strncmp(*av,CH_BLK,strlen(CH_BLK)) || !strncmp(*av,CH_FWD,strlen(CH_FWD))) { if (kvm_nlist(kd,nlf)<0 || nlf[0].n_type==0) { fprintf(stderr,"%s: kvm_nlist: no namelist in %s\n", progname,getbootfile()); exit(1); } } if (*av==NULL || !strncmp(*av,CH_BLK,strlen(CH_BLK))) { kvm_read(kd,(u_long)nlf[N_BCHAIN].n_value,&b,sizeof(struct ip_fw)); printf("Blocking chain entries:\n"); while(b.next!=NULL) { btmp=b.next; kvm_read(kd,(u_long)btmp,&b,sizeof(struct ip_fw)); show_ipfw(&b,FW); } } if (*av==NULL || !strncmp(*av,CH_FWD,strlen(CH_FWD))) { kvm_read(kd,(u_long)nlf[N_FCHAIN].n_value,&b,sizeof(struct ip_fw)); printf("Forwarding chain entries:\n"); while(b.next!=NULL) { btmp=b.next; kvm_read(kd,(u_long)btmp,&b,sizeof(struct ip_fw)); show_ipfw(&b,FW); } } if (*av==NULL || !strncmp(*av,CH_AC,strlen(CH_AC))) { if (kvm_nlist(kd,nla)<0 || nla[0].n_type==0) { fprintf(stderr,"%s: kvm_nlist: no namelist in %s\n", progname,getbootfile()); exit(1); } } if (*av==NULL || !strncmp(*av,CH_AC,strlen(CH_AC))) { kvm_read(kd,(u_long)nla[N_ACHAIN].n_value,&b,sizeof(struct ip_fw)); printf("Accounting chain entries:\n"); while(b.next!=NULL) { btmp=b.next; kvm_read(kd,(u_long)btmp,&b,sizeof(struct ip_fw)); show_ipfw(&b,AC); } } } int get_num(str,tab) char *str; char tab[][MAXSTR]; { int i=0; while(tab[i][0]!='\0') { if (strlen(str)>=strlen(tab[i])) if (!strncmp(str,tab[i],strlen(tab[i]))) return i; i++; } return i; } void show_usage() { printf("%s: bad arguments\n",progname); } u_short get_port(str) char *str; { struct servent *sptr; char *end; int port,slen = strlen(str); if ((slen>0) && (strspn(str,"0123456789")==slen)) { port = strtol(str,&end,10); if (*end!='\0') { fprintf(stderr,"%s: illegal port number :%s\n" ,progname,str); exit(1); } if ((port<=0) || (port>USHRT_MAX)) { fprintf(stderr,"%s: port number out of range :%d\n" ,progname,port); exit(1); } return((u_short)port); } else { sptr = getservbyname(str,proto_name); if (!sptr) { fprintf(stderr,"%s: unknown service :%s\n" ,progname,str); exit(1); } return((u_short)ntohs(sptr->s_port)); } } char *findchar(str,c) char *str; char c; { int i,len=strlen(str); for (i=0;ia_max) { fprintf(stderr,"%s: too many ports.\n",progname); exit(1); } *cp='\0'; if ((s_t=(++cp))=='\0') { fprintf(stderr,"%s: bad port list.\n",progname); exit(1); } ports[i++]=get_port(s_h); s_h=s_t; } if (i>a_max) { fprintf(stderr,"%s: too many ports.\n",progname); exit(1); } ports[i]=get_port(s_h); *is_range=0; return (i+1); } void set_entry_ip(str,addr,mask) char *str; struct in_addr *addr,*mask; { char *sm_bit,*sm_oct,*end; int n_bit; struct hostent *hptr; (void)strtok(str,"/"); sm_bit=strtok(NULL,""); (void)strtok(str,":"); sm_oct=strtok(NULL,""); if (!inet_aton(str,addr)) { if (do_resolv) { if (!(hptr=gethostbyname(str))) { fprintf(stderr,"%s: Unknown host name : %s\n", progname,str); exit(1); } else { addr->s_addr=*((u_long *)hptr->h_addr); } } else { fprintf(stderr,"%s: Bad IP : %s\n",progname,str); exit(1); } } mask->s_addr=htonl(ULONG_MAX); if (sm_bit) { n_bit = strtol(sm_bit,&end,10); if (*end!='\0') { show_usage(); exit(1); } if (n_bit<0 || n_bit>sizeof(u_long)*CHAR_BIT) { show_usage(); exit(1); } mask->s_addr= htonl(ULONG_MAX<<(sizeof(u_long)*CHAR_BIT-n_bit)); } if (sm_oct) { if (!inet_aton(sm_oct,mask)) { show_usage(); exit(1); } } /* * Ugh..better of corse do it in kernel so no error possible * but faster here so this way it goes... */ addr->s_addr=mask->s_addr & addr->s_addr; } void set_entry(av,frwl) char **av; struct ip_fw * frwl; { int p_num=0,ir=0; frwl->n_src_p=0; frwl->n_dst_p=0; if (strncmp(*av,S_SEP1,strlen(S_SEP1))) { show_usage(); exit(1); } if (*(++av)==NULL) { show_usage(); exit(1); } set_entry_ip(*av,&(frwl->src),&(frwl->src_mask)); if (*(++av)==NULL) { show_usage(); exit(1); } if (!strncmp(*av,S_SEP2,strlen(S_SEP2))) goto no_src_ports; if (ports_ok) { frwl->n_src_p= set_entry_ports(*av,frwl->ports,IP_FW_MAX_PORTS,&ir); if (ir) flags|=IP_FW_F_SRNG; if (*(++av)==NULL) { show_usage(); exit(1); } } no_src_ports: if (strncmp(*av,S_SEP2,strlen(S_SEP2))) { show_usage(); exit(1); } if (*(++av)==NULL) { show_usage(); exit(1); } set_entry_ip(*av,&(frwl->dst),&(frwl->dst_mask)); if (*(++av)==NULL) goto no_dst_ports; if (ports_ok) { frwl->n_dst_p= set_entry_ports(*av,&(frwl->ports[frwl->n_src_p]), (IP_FW_MAX_PORTS-frwl->n_src_p),&ir); if (ir) flags|=IP_FW_F_DRNG; } no_dst_ports: } flush(av) char **av; { if (*av==NULL) { if (setsockopt(s,IPPROTO_IP,IP_FW_FLUSH,NULL,0)<0) { fprintf(stderr,"%s: setsockopt failed.\n",progname); exit(1); } else { printf("All firewall entries flushed.\n"); } if (setsockopt(s,IPPROTO_IP,IP_ACCT_FLUSH,NULL,0)<0) { fprintf(stderr,"%s: setsockopt failed.\n",progname); exit(1); } else { printf("All accounting entries flushed.\n"); } exit(0); } if (!strncmp(*av,CH_FW,strlen(CH_FW))) { if (setsockopt(s,IPPROTO_IP,IP_FW_FLUSH,NULL,0)<0) { fprintf(stderr,"%s: setsockopt failed.\n",progname); exit(1); } else { printf("All firewall entries flushed.\n"); exit(0); } } if (!strncmp(*av,CH_AC,strlen(CH_AC))) { if (setsockopt(s,IPPROTO_IP,IP_ACCT_FLUSH,NULL,0)<0) { fprintf(stderr,"%s: setsockopt failed.\n",progname); exit(1); } else { printf("All accounting entries flushed.\n"); exit(0); } } } void policy(av) char **av; { int p; kvm_t *kd; static char errb[_POSIX2_LINE_MAX]; int b; if (*av==NULL || strlen(*av)<=0) { if ( (kd=kvm_openfiles(NULL,NULL,NULL,O_RDONLY,errb)) == NULL) { fprintf(stderr,"%s: kvm_openfiles: %s\n",progname,kvm_geterr(kd)); exit(1); } if (kvm_nlist(kd,nlf) < 0 || nlf[0].n_type == 0) { fprintf(stderr,"%s: kvm_nlist: no namelist in %s\n", progname,getbootfile()); exit(1); } kvm_read(kd,(u_long)nlf[N_POLICY].n_value,&b,sizeof(int)); if (b==1) printf("Default policy: ACCEPT\n"); if (b==0) printf("Default policy: DENY\n"); if (b!=0 && b!=1) printf("Wrong policy value\n"); exit(1); } if (!strncmp(*av,P_DE,strlen(P_DE))) p=0; else if (!strncmp(*av,P_AC,strlen(P_AC))) p=1; else { fprintf(stderr,"%s: bad policy value.\n",progname); exit(1); } if (setsockopt(s,IPPROTO_IP,IP_FW_POLICY,&p,sizeof(p))<0) { fprintf(stderr,"%s: setsockopt failed.\n",progname); exit(1); } else { if (p) printf("Policy set to ACCEPT.\n"); else printf("Policy set to DENY.\n"); exit(0); } } zero() { if (setsockopt(s,IPPROTO_IP,IP_ACCT_ZERO,NULL,0)<0) { fprintf(stderr,"%s: setsockopt failed.\n",progname); exit(1); } else { printf("Accounting cleared.\n"); exit(0); } } main(ac,av) int ac; char **av; { char ch; extern int optind; int ctl,int_t,is_check=0; struct ip_fw frwl; strcpy(progname,*av); s = socket( AF_INET, SOCK_RAW, IPPROTO_RAW ); if ( s < 0 ) { fprintf(stderr,"%s: Can't open raw socket.Must be root to use this programm. \n",progname); exit(1); } if ( ac == 1 ) { show_usage(); exit(1); } while ((ch = getopt(ac, av ,"nv")) != EOF) switch(ch) { case 'n': do_resolv=0; break; case 'v': do_verbose=1; break; case '?': default: show_usage(); exit(1); } if (*(av+=optind)==NULL) { show_usage(); exit(1); } switch(get_num(*av,action_tab)) { case A_ADDB: ctl=IP_FW_ADD_BLK; int_t=FW; break; case A_DELB: ctl=IP_FW_DEL_BLK; int_t=FW; break; case A_CHKB: ctl=IP_FW_CHK_BLK; int_t=FW; is_check=1; break; case A_ADDF: ctl=IP_FW_ADD_FWD; int_t=FW; break; case A_DELF: ctl=IP_FW_DEL_FWD; int_t=FW; break; case A_CHKF: ctl=IP_FW_CHK_FWD; int_t=FW; is_check=1; break; case A_ADDA: ctl=IP_ACCT_ADD; int_t=AC; break; case A_DELA: ctl=IP_ACCT_DEL; int_t=AC; break; case A_FLUSH: flush(++av); exit(0); /* successful exit */ case A_LIST: list(++av); exit(0); /* successful exit */ case A_ZERO: zero(); exit(0); /* successful exit */ case A_POLICY: policy(++av); exit(0); /* we never get here */ default: show_usage(); exit(1); } /* main action switch */ if (is_check) goto proto_switch; if (*(++av)==NULL) { show_usage(); exit(1); } switch(get_num(*av,type_tab)) { case T_DENY: flags|=0; /* just to show it related to flags */ if (int_t!=FW) { show_usage(); exit(1); } break; case T_ACCEPT: flags|=IP_FW_F_ACCEPT; if (int_t!=FW) { show_usage(); exit(1); } break; case T_SINGLE: flags|=0; /* just to show it related to flags */ if (int_t!=AC) { show_usage(); exit(1); } break; case T_BIDIR: flags|=IP_FW_F_BIDIR; if (int_t!=AC) { show_usage(); exit(1); } break; } /* type of switch */ proto_switch: if (*(++av)==NULL) { show_usage(); exit(1); } switch(get_num(*av,proto_tab)) { case P_ALL: flags|=IP_FW_F_ALL; break; case P_ICMP: flags|=IP_FW_F_ICMP; break; case P_TCP: flags|=IP_FW_F_TCP; ports_ok=1; strcpy(proto_name,"tcp"); break; case P_UDP: flags|=IP_FW_F_UDP; ports_ok=1; strcpy(proto_name,"udp"); break; default: show_usage(); exit(1); } if (*(++av)==NULL) { show_usage(); exit(1); } set_entry(av,&frwl); if (do_verbose) flags|=IP_FW_F_PRN; frwl.flags=flags; if (is_check) { struct ip *pkt; struct tcphdr *th; int p_len=sizeof(struct ip)+sizeof(struct tcphdr); pkt=(struct ip*)malloc(p_len); pkt->ip_v = IPVERSION; pkt->ip_hl = sizeof(struct ip)/sizeof(int); th=(struct tcphdr *)(pkt+1); switch(get_num(proto_name,proto_tab)) { case P_TCP: pkt->ip_p = IPPROTO_TCP; break; case P_UDP: pkt->ip_p = IPPROTO_UDP; break; default: fprintf(stderr,"%s: can check TCP/UDP packets\ only.\n",progname); exit(1); } if (frwl.n_src_p!=1 || frwl.n_dst_p!=1) { fprintf(stderr,"%s: check needs one src/dst port.\n", progname); exit(1); } if (ntohl(frwl.src_mask.s_addr)!=ULONG_MAX || ntohl(frwl.dst_mask.s_addr)!=ULONG_MAX) { fprintf(stderr,"%s: can't check masked IP.\n",progname); exit(1); } pkt->ip_src.s_addr=frwl.src.s_addr; pkt->ip_dst.s_addr=frwl.dst.s_addr; th->th_sport=htons(frwl.ports[0]); th->th_dport=htons(frwl.ports[frwl.n_src_p]); if (setsockopt(s,IPPROTO_IP,ctl,pkt,p_len)) printf("Packet DENYED.\n"); else printf("Packet ACCEPTED.\n"); exit(0); } else { if (setsockopt(s,IPPROTO_IP,ctl,&frwl,sizeof(frwl))<0) { fprintf(stderr,"%s: setsockopt failed.\n",progname); exit(1); } } /* * Here the entry have to be added but not yet... */ close(s); }