win_bpf_filter.c

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			return 0;

		case BPF_RET|BPF_K:
			return (u_int)pc->k;

		case BPF_RET|BPF_A:
			return (u_int)A;

		case BPF_LD|BPF_W|BPF_ABS:
			k = pc->k;
			if (k + sizeof(int32) > buflen) {
				return 0;
			}
			
			if(k + (int)sizeof(int32) < headersize) A = EXTRACT_LONG(&p[k]);
			else if(k + 2 == headersize){
				A=(u_int32)*((u_char *)p+k)<<24|
					(u_int32)*((u_char *)p+k+1)<<16|
					(u_int32)*((u_char *)p+k+2)<<8|
					(u_int32)*((u_char *)pd+k-headersize);
			}
			else if(k == headersize-1){
				A=(u_int32)*((u_char *)p+k)<<24|
					(u_int32)*((u_char *)p+k+1)<<16|
					(u_int32)*((u_char *)pd+k-headersize)<<8|
					(u_int32)*((u_char *)pd+k-headersize+1);
			}
			else if(k == headersize){
				A=(u_int32)*((u_char *)p+k)<<24|
					(u_int32)*((u_char *)pd+k-headersize+1)<<16|
					(u_int32)*((u_char *)pd+k-headersize+2)<<8|
					(u_int32)*((u_char *)pd+k-headersize+3);
			}
			A = EXTRACT_LONG(&pd[k-headersize]);
			
			continue;
			
		case BPF_LD|BPF_H|BPF_ABS:
			k = pc->k;
			if (k + sizeof(short) > buflen) {
				return 0;
			}
			
			if(k + (int)sizeof(short) < headersize) A = EXTRACT_SHORT(&p[k]);
			else if(k == headersize){
				A=(u_short)*((u_char *)p+k)<<8|
					(u_short)*((u_char *)pd+k-headersize);
			}
			A = EXTRACT_SHORT(&pd[k-headersize]);
			
			continue;

		case BPF_LD|BPF_B|BPF_ABS:
			k = pc->k;
			if ((int)k >= (int)buflen) {
				return 0;
			}

			if(k<headersize) A = p[k];
			 else A = pd[k-headersize];

			continue;

		case BPF_LD|BPF_W|BPF_LEN:
			A = wirelen;
			continue;

		case BPF_LDX|BPF_W|BPF_LEN:
			X = wirelen;
			continue;

		case BPF_LD|BPF_W|BPF_IND:
			k = X + pc->k;
			if (k + sizeof(int32) > buflen) {
				return 0;
			}

			if(k + (int)sizeof(int32) < headersize) A = EXTRACT_LONG(&p[k]);
			else if(k + (int)sizeof(int32) == headersize+2){
				A=(u_int32)*((u_char *)p+k)<<24|
					(u_int32)*((u_char *)p+k+1)<<16|
					(u_int32)*((u_char *)p+k+2)<<8|
					(u_int32)*((u_char *)pd+k-headersize);
			}
			else if(k + (int)sizeof(int32) == headersize+3){
				A=(u_int32)*((u_char *)p+k)<<24|
					(u_int32)*((u_char *)p+k+1)<<16|
					(u_int32)*((u_char *)pd+k-headersize)<<8|
					(u_int32)*((u_char *)pd+k-headersize+1);
			}
			else if(k + (int)sizeof(int32) == headersize+4){
				A=(u_int32)*((u_char *)p+k)<<24|
					(u_int32)*((u_char *)pd+k-headersize+1)<<16|
					(u_int32)*((u_char *)pd+k-headersize+2)<<8|
					(u_int32)*((u_char *)pd+k-headersize+3);
			}
			A = EXTRACT_LONG(&pd[k-headersize]);
			
			continue;
			
		case BPF_LD|BPF_H|BPF_IND:
			k = X + pc->k;
			if (k + sizeof(short) > buflen) {
				return 0;
			}
			
			if(k + (int)sizeof(short) < headersize) A = EXTRACT_SHORT(&p[k]);
			else if(k == headersize){
				A=(u_short)*((u_char *)p+k)<<8|
					(u_short)*((u_char *)pd+k-headersize);
			}
			A = EXTRACT_SHORT(&pd[k-headersize]);

			continue;

		case BPF_LD|BPF_B|BPF_IND:
			k = X + pc->k;
			if ((int)k >= (int)buflen) {
				return 0;
			}

			if(k<headersize) A = p[k];
			 else A = pd[k-headersize];

			continue;

		case BPF_LDX|BPF_MSH|BPF_B:
			k = pc->k;
			if ((int)k >= (int)buflen) {
				return 0;
			}
			
			if((pc->k)<headersize) X = (p[pc->k] & 0xf) << 2;
			 else X = (pd[(pc->k)-headersize] & 0xf) << 2;

			continue;

		case BPF_LD|BPF_IMM:
			A = pc->k;
			continue;

		case BPF_LDX|BPF_IMM:
			X = pc->k;
			continue;

		case BPF_LD|BPF_MEM:
			A = mem[pc->k];
			continue;
			
		case BPF_LDX|BPF_MEM:
			X = mem[pc->k];
			continue;

/* LD NO PACKET INSTRUCTIONS */

		case BPF_LD|BPF_MEM_EX_IMM|BPF_B:
			A= mem_ex->buffer[pc->k];
			continue;

		case BPF_LDX|BPF_MEM_EX_IMM|BPF_B:
			X= mem_ex->buffer[pc->k];
			continue;

		case BPF_LD|BPF_MEM_EX_IMM|BPF_H:
			A = EXTRACT_SHORT(&mem_ex->buffer[pc->k]);
			continue;

		case BPF_LDX|BPF_MEM_EX_IMM|BPF_H:
			X = EXTRACT_SHORT(&mem_ex->buffer[pc->k]);
			continue;

		case BPF_LD|BPF_MEM_EX_IMM|BPF_W:
			A = EXTRACT_LONG(&mem_ex->buffer[pc->k]);
			continue;

		case BPF_LDX|BPF_MEM_EX_IMM|BPF_W:
			X = EXTRACT_LONG(&mem_ex->buffer[pc->k]);
			continue;
			
		case BPF_LD|BPF_MEM_EX_IND|BPF_B:
			k = X + pc->k;
			if ((int32)k>= (int32)mem_ex->size) {
				return 0;
			}
			A= mem_ex->buffer[k];
			continue;

		case BPF_LD|BPF_MEM_EX_IND|BPF_H:
			k = X + pc->k;
			if ((int32)(k+1)>= (int32)mem_ex->size) {
				return 0;
			}
			A=EXTRACT_SHORT((uint32*)&mem_ex->buffer[k]);
			continue;

		case BPF_LD|BPF_MEM_EX_IND|BPF_W:
			k = X + pc->k;
			if ((int32)(k+3)>= (int32)mem_ex->size) {
				return 0;
			}
			A=EXTRACT_LONG((uint32*)&mem_ex->buffer[k]);
			continue;
/* END LD NO PACKET INSTRUCTIONS */
		
		case BPF_ST:
			mem[pc->k] = A;
			continue;

		case BPF_STX:
			mem[pc->k] = X;
			continue;


/* STORE INSTRUCTIONS */
		case BPF_ST|BPF_MEM_EX_IMM|BPF_B:
			mem_ex->buffer[pc->k]=(uint8)A;
			continue;

		case BPF_STX|BPF_MEM_EX_IMM|BPF_B:
			mem_ex->buffer[pc->k]=(uint8)X;
			continue;

		case BPF_ST|BPF_MEM_EX_IMM|BPF_W:
			tmp=A;
			*(uint32*)&(mem_ex->buffer[pc->k])=EXTRACT_LONG(&tmp);
			continue;

		case BPF_STX|BPF_MEM_EX_IMM|BPF_W:
			tmp=X;
			*(uint32*)&(mem_ex->buffer[pc->k])=EXTRACT_LONG(&tmp);
			continue;

		case BPF_ST|BPF_MEM_EX_IMM|BPF_H:
			tmp2=(uint16)A;
			*(uint16*)&mem_ex->buffer[pc->k]=EXTRACT_SHORT(&tmp2);
			continue;

		case BPF_STX|BPF_MEM_EX_IMM|BPF_H:
			tmp2=(uint16)X;
			*(uint16*)&mem_ex->buffer[pc->k]=EXTRACT_SHORT(&tmp2);
			continue;

		case BPF_ST|BPF_MEM_EX_IND|BPF_B:
			mem_ex->buffer[pc->k+X]=(uint8)A;

		case BPF_ST|BPF_MEM_EX_IND|BPF_W:
			tmp=A;
			*(uint32*)&mem_ex->buffer[pc->k+X]=EXTRACT_LONG(&tmp);
			continue;

		case BPF_ST|BPF_MEM_EX_IND|BPF_H:
			tmp2=(uint16)A;
			*(uint16*)&mem_ex->buffer[pc->k+X]=EXTRACT_SHORT(&tmp2);
			continue;
/* END STORE INSTRUCTIONS */
		
		
		
		case BPF_JMP|BPF_JA:
			pc += pc->k;
			continue;

		case BPF_JMP|BPF_JGT|BPF_K:
			pc += ((int)A > (int)pc->k) ? pc->jt : pc->jf;
			continue;

		case BPF_JMP|BPF_JGE|BPF_K:
			pc += ((int)A >= (int)pc->k) ? pc->jt : pc->jf;
			continue;

		case BPF_JMP|BPF_JEQ|BPF_K:
			pc += ((int)A == (int)pc->k) ? pc->jt : pc->jf;
			continue;

		case BPF_JMP|BPF_JSET|BPF_K:
			pc += (A & pc->k) ? pc->jt : pc->jf;
			continue;

		case BPF_JMP|BPF_JGT|BPF_X:
			pc += (A > X) ? pc->jt : pc->jf;
			continue;

		case BPF_JMP|BPF_JGE|BPF_X:
			pc += (A >= X) ? pc->jt : pc->jf;
			continue;

		case BPF_JMP|BPF_JEQ|BPF_X:
			pc += (A == X) ? pc->jt : pc->jf;
			continue;

		case BPF_JMP|BPF_JSET|BPF_X:
			pc += (A & X) ? pc->jt : pc->jf;
			continue;

		case BPF_ALU|BPF_ADD|BPF_X:
			A += X;
			continue;
			
		case BPF_ALU|BPF_SUB|BPF_X:
			A -= X;
			continue;
			
		case BPF_ALU|BPF_MUL|BPF_X:
			A *= X;
			continue;
			
		case BPF_ALU|BPF_DIV|BPF_X:
			if (X == 0)
				return 0;
			A /= X;
			continue;
			
		case BPF_ALU|BPF_AND|BPF_X:
			A &= X;
			continue;
			
		case BPF_ALU|BPF_OR|BPF_X:
			A |= X;
			continue;

		case BPF_ALU|BPF_LSH|BPF_X:
			A <<= X;
			continue;

		case BPF_ALU|BPF_RSH|BPF_X:
			A >>= X;
			continue;

		case BPF_ALU|BPF_ADD|BPF_K:
			A += pc->k;
			continue;
			
		case BPF_ALU|BPF_SUB|BPF_K:
			A -= pc->k;
			continue;
			
		case BPF_ALU|BPF_MUL|BPF_K:
			A *= pc->k;
			continue;
			
		case BPF_ALU|BPF_DIV|BPF_K:
			A /= pc->k;
			continue;
			
		case BPF_ALU|BPF_AND|BPF_K:
			A &= pc->k;
			continue;
			
		case BPF_ALU|BPF_OR|BPF_K:
			A |= pc->k;
			continue;

		case BPF_ALU|BPF_LSH|BPF_K:
			A <<= pc->k;
			continue;

		case BPF_ALU|BPF_RSH|BPF_K:
			A >>= pc->k;
			continue;

		case BPF_ALU|BPF_NEG:
			(int)A = -((int)A);
			continue;

		case BPF_MISC|BPF_TAX:
			X = A;
			continue;

		case BPF_MISC|BPF_TXA:
			A = X;
			continue;

/* TME INSTRUCTIONS */
		case BPF_MISC|BPF_TME|BPF_LOOKUP:
			j=lookup_frontend(mem_ex,tme,pc->k,time_ref);
			if (j==TME_ERROR)
				return 0;	
			pc += (j == TME_TRUE) ? pc->jt : pc->jf;
			continue;

		case BPF_MISC|BPF_TME|BPF_EXECUTE:
			if (execute_frontend(mem_ex,tme,wirelen,pc->k)==TME_ERROR)
				return 0;
			continue;

		case BPF_MISC|BPF_TME|BPF_SET_ACTIVE:
			if (set_active_tme_block(tme,pc->k)==TME_ERROR)
				return 0;
			continue;

		case BPF_MISC|BPF_TME|BPF_GET_REGISTER_VALUE:
			if (get_tme_block_register(&tme->block_data[tme->working],mem_ex,pc->k,&j)==TME_ERROR)
				return 0;
			A=j;
			continue;

		case BPF_MISC|BPF_TME|BPF_SET_REGISTER_VALUE:
			if (set_tme_block_register(&tme->block_data[tme->working],mem_ex,pc->k,A,FALSE)==TME_ERROR)
				return 0;
			continue;
/* END TME INSTRUCTIONS */

		}
	}
}

int32
bpf_validate(f, len,mem_ex_size)
	struct bpf_insn *f;
	int32 len;
	uint32 mem_ex_size;	
{
	register int32 i,j;
	register struct bpf_insn *p;
	int32 flag;
		
	for (i = 0; i < len; ++i) {
		/*
		 * Check that that jumps are forward, and within 
		 * the code block.
		 */
		
		p = &f[i];

		IF_LOUD(DbgPrint("Validating program");)
		
		flag=0;
		for(j=0;j<VALID_INSTRUCTIONS_LEN;j++)
			if (p->code==valid_instructions[j])
				flag=1;
		if (flag==0)
			return 0;

		IF_LOUD(DbgPrint("Validating program: no unknown instructions");)
		
		if (BPF_CLASS(p->code) == BPF_JMP) {
			register int32 from = i + 1;

			if (BPF_OP(p->code) == BPF_JA) {
				if (from + p->k >= len)
					return 0;
			}
			else if (from + p->jt >= len || from + p->jf >= len)
				return 0;
		}

		IF_LOUD(DbgPrint("Validating program: no wrong JUMPS");)
	
		/*
		 * Check that memory operations use valid addresses.
		 */
		if (((BPF_CLASS(p->code) == BPF_ST && ((p->code &BPF_MEM_EX_IMM)!=BPF_MEM_EX_IMM && (p->code &BPF_MEM_EX_IND)!=BPF_MEM_EX_IND)) ||
		     (BPF_CLASS(p->code) == BPF_LD && 
		      (p->code & 0xe0) == BPF_MEM)) &&
			  (p->k >= BPF_MEMWORDS || p->k < 0))
			return 0;
		
		IF_LOUD(DbgPrint("Validating program: no wrong ST/LD memory locations");)
			
		/*
		 * Check if key stores use valid addresses 
		 */ 
		if (BPF_CLASS(p->code) == BPF_ST && (p->code &BPF_MEM_EX_IMM)==BPF_MEM_EX_IMM)
	    switch (BPF_SIZE(p->code))
		{
			case BPF_W: if (p->k<0 || p->k+3>=(int32)mem_ex_size) return 0;
			case BPF_H: if (p->k<0 || p->k+1>=(int32)mem_ex_size) return 0;
			case BPF_B: if (p->k<0 || p->k>=(int32)mem_ex_size) return 0;
		}

		IF_LOUD(DbgPrint("Validating program: no wrong ST/LD mem_ex locations");)

		/*
		 * Check for constant division by 0.
		 */
		if (p->code == (BPF_ALU|BPF_DIV|BPF_K) && p->k == 0)
			return 0;
	}
	return BPF_CLASS(f[len - 1].code) == BPF_RET;
}