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Introduce socklen_t; detect non-local (e.g. broadcast) receive addresses

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This commit is contained in:
H. Peter Anvin 2006-10-04 21:54:04 -07:00
parent f3beb3a119
commit 14993bc916
7 changed files with 68 additions and 20 deletions
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47
tftpd/recvfrom.c
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@ -50,9 +50,50 @@ struct in_pktinfo {
# define CMSG_SPACE(size) (sizeof(struct cmsghdr) + (size))
#endif
/*
* Check to see if this is a valid local address. If so, we should
* end up having the same local and remote address when trying to
* bind to it.
*/
static int address_is_local(const struct sockaddr_in *addr)
{
struct sockaddr_in sin;
int sockfd = -1;
int e;
int rv = 0;
socklen_t addrlen;
/* Multicast or universal broadcast address? */
if (ntohl(addr->sin_addr.s_addr) >= (224UL << 24))
return 0;
sockfd = socket(PF_INET, SOCK_DGRAM, 0);
if (sockfd < 0)
goto err;
if (connect(sockfd, (const struct sockaddr *)addr, sizeof *addr))
goto err;
addrlen = sizeof sin;
if (getsockname(sockfd, (struct sockaddr *)&sin, &addrlen))
goto err;
rv = sin.sin_addr.s_addr == addr->sin_addr.s_addr;
err:
e = errno;
if (sockfd >= 0)
close(sockfd);
errno = e;
return rv;
}
int
myrecvfrom(int s, void *buf, int len, unsigned int flags,
struct sockaddr *from, int *fromlen,
struct sockaddr *from, socklen_t *fromlen,
struct sockaddr_in *myaddr)
{
struct msghdr msg;
@ -128,6 +169,10 @@ myrecvfrom(int s, void *buf, int len, unsigned int flags,
}
}
/* If the address is not a valid local address, then bind to any address... */
if (address_is_local(myaddr) != 1)
myaddr->sin_addr.s_addr = INADDR_ANY;
return n;
}