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#include <assert.h>
#include <fs/vfs.h>
#include <math.h>
#include <poll.h>
#include <scalls/recvfrom.h>
size_t syscall_recvfrom(
int socket, void *buffer, size_t length, int flags,
struct two_args
*extra_args /*struct sockaddr *address, socklen_t *address_len*/) {
struct sockaddr *address = (struct sockaddr *)extra_args->a;
socklen_t *address_len = (socklen_t *)extra_args->b;
kprintf("address: %x\n", address);
kprintf("address_len: %x\n", address_len);
if (flags & MSG_WAITALL) {
struct pollfd fds[1];
fds[0].fd = socket;
fds[0].events = POLLIN;
poll(fds, 1, 0);
}
uint16_t data_length;
socklen_t tmp_socklen;
vfs_pread(socket, &tmp_socklen, sizeof(socklen_t), 0);
if (address_len)
*address_len = tmp_socklen;
if (address) {
vfs_pread(socket, address, tmp_socklen, 0);
} else {
// We still have to throwaway the data.
char devnull[100];
for (; tmp_socklen;) {
int rc = vfs_pread(socket, devnull, min(tmp_socklen, 100), 0);
assert(rc >= 0);
tmp_socklen -= rc;
}
}
vfs_pread(socket, &data_length, sizeof(data_length), 0);
// If it is reading less than the packet length that could cause
// problems as the next read will not be put at a new header. Luckily
// it seems as if other UNIX systems can discard the rest of the
// packet if not read.
// Read in the data requested
int read_len = min(length, data_length);
int rc = vfs_pread(socket, buffer, read_len, 0);
// Discard the rest of the packet
int rest = data_length - read_len;
char devnull[100];
for (; rest;) {
int rc = vfs_pread(socket, devnull, 100, 0);
assert(rc >= 0);
rest -= rc;
}
return rc;
}
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