121 lines
		
	
	
		
			2.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			121 lines
		
	
	
		
			2.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| #undef NDEBUG
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| 
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| #include <assert.h>
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| #include <errno.h>
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| #include <stdlib.h>
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| #include <stdio.h>
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| #include <string.h>
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| #include <unistd.h>
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| #include <sys/ioctl.h>
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| #include <sys/socket.h>
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| #include <netinet/in.h>
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| 
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| #include <net/gen/in.h>
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| #include <net/gen/udp.h>
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| #include <net/gen/udp_hdr.h>
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| #include <net/gen/udp_io.h>
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| 
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| #define DEBUG 0
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| 
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| static ssize_t _udp_recvfrom(int socket, void *_RESTRICT buffer, size_t length,
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| 	int flags, struct sockaddr *_RESTRICT address,
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| 	socklen_t *_RESTRICT address_len, nwio_udpopt_t *udpoptp);
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| 
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| ssize_t recvfrom(int socket, void *_RESTRICT buffer, size_t length,
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| 	int flags, struct sockaddr *_RESTRICT address,
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| 	socklen_t *_RESTRICT address_len)
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| {
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| 	int r;
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| 	nwio_udpopt_t udpopt;
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| 
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| 	fprintf(stderr, "recvfrom: for fd %d\n", socket);
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| 
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| 	r= ioctl(socket, NWIOGUDPOPT, &udpopt);
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| 	if (r != -1 || (errno != ENOTTY && errno != EBADIOCTL))
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| 	{
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| 		if (r == -1)
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| 			return r;
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| 		return _udp_recvfrom(socket, buffer, length, flags,
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| 			address, address_len, &udpopt);
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| 	}
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| 
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| #if DEBUG
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| 	fprintf(stderr, "recvfrom: not implemented for fd %d\n", socket);
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| #endif
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| 	errno= ENOSYS;
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| 	assert(0);
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| 	return -1;
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| }
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| 
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| static ssize_t _udp_recvfrom(int socket, void *_RESTRICT buffer, size_t length,
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| 	int flags, struct sockaddr *_RESTRICT address,
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| 	socklen_t *_RESTRICT address_len, nwio_udpopt_t *udpoptp)
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| {
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| 	int r, t_errno;
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| 	size_t buflen, len;
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| 	void *buf;
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| 	struct sockaddr_in *sinp;
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| 	udp_io_hdr_t *io_hdrp;
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| 	struct sockaddr_in sin;
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| 
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| 	if (flags)
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| 	{
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| #if DEBUG
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| 		fprintf(stderr, "recvfrom(udp): flags not implemented\n");
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| #endif
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| 		errno= ENOSYS;
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| 		return -1;
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| 	}
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| 
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| 	if (udpoptp->nwuo_flags & NWUO_RWDATONLY)
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| 	{
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| #if DEBUG
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| 		fprintf(stderr,
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| 			"recvfrom(udp): NWUO_RWDATONLY not implemented\n");
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| #endif
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| 		errno= ENOSYS;
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| 		return -1;
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| 	}
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| 
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| 	buflen= sizeof(*io_hdrp) + length;
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| 	if (buflen < length)
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| 	{	
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| 		/* Overflow */
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| 		errno= EMSGSIZE;
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| 		return -1;
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| 	}
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| 	buf= malloc(buflen);
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| 	if (buf == NULL)
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| 		return -1;
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| 
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| 	r= read(socket, buf, buflen);
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| 	if (r == -1)
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| 	{
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| 		t_errno= errno;
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| 		free(buf);
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| 		errno= t_errno;
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| 		return -1;
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| 	}
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| 
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| 	assert(r >= sizeof(*io_hdrp));
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| 	length= r-sizeof(*io_hdrp);
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| 
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| 	io_hdrp= buf;
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| 	memcpy(buffer, &io_hdrp[1], length);
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| 
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| 	if (address != NULL)
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| 	{
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| 		sin.sin_family= AF_INET;
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| 		sin.sin_addr.s_addr= io_hdrp->uih_src_addr;
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| 		sin.sin_port= io_hdrp->uih_src_port;
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| 		len= *address_len;
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| 		if (len > sizeof(sin))
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| 			len= sizeof(sin);
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| 		memcpy(address, &sin, len);
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| 		*address_len= sizeof(sin);
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| 	}	
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| 	free(buf);
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| 	return length;
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| }
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| 
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