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//
// network system calls.
//
#include "types.h"
#include "param.h"
#include "memlayout.h"
#include "riscv.h"
#include "spinlock.h"
#include "proc.h"
#include "defs.h"
#include "fs.h"
#include "sleeplock.h"
#include "file.h"
#include "net.h"
struct sock {
struct sock *next; // the next socket in the list
uint32 raddr; // the remote IPv4 address
uint16 lport; // the local UDP port number
uint16 rport; // the remote UDP port number
struct spinlock lock; // protects the rxq
struct mbufq rxq; // a queue of packets waiting to be received
};
static struct spinlock lock;
static struct sock *sockets;
void
sockinit(void)
{
initlock(&lock, "socktbl");
}
int
sockalloc(struct file **f, uint32 raddr, uint16 lport, uint16 rport)
{
struct sock *si, *pos;
si = 0;
*f = 0;
if ((*f = filealloc()) == 0)
goto bad;
if ((si = (struct sock*)kalloc()) == 0)
goto bad;
// initialize objects
si->raddr = raddr;
si->lport = lport;
si->rport = rport;
initlock(&si->lock, "sock");
mbufq_init(&si->rxq);
(*f)->type = FD_SOCK;
(*f)->readable = 1;
(*f)->writable = 1;
(*f)->sock = si;
// add to list of sockets
acquire(&lock);
pos = sockets;
while (pos) {
if (pos->raddr == raddr &&
pos->lport == lport &&
pos->rport == rport) {
release(&lock);
goto bad;
}
pos = pos->next;
}
si->next = sockets;
sockets = si;
release(&lock);
return 0;
bad:
if (si)
kfree((char*)si);
if (*f)
fileclose(*f);
return -1;
}
void
sockclose(struct sock *si)
{
struct sock **pos;
struct mbuf *m;
// remove from list of sockets
acquire(&lock);
pos = &sockets;
while (*pos) {
if (*pos == si){
*pos = si->next;
break;
}
pos = &(*pos)->next;
}
release(&lock);
// free any pending mbufs
while (!mbufq_empty(&si->rxq)) {
m = mbufq_pophead(&si->rxq);
mbuffree(m);
}
kfree((char*)si);
}
int
sockread(struct sock *si, uint64 addr, int n)
{
struct proc *pr = myproc();
struct mbuf *m;
int len;
acquire(&si->lock);
while (mbufq_empty(&si->rxq) && !pr->killed) {
sleep(&si->rxq, &si->lock);
}
if (pr->killed) {
release(&si->lock);
return -1;
}
m = mbufq_pophead(&si->rxq);
release(&si->lock);
len = m->len;
if (len > n)
len = n;
if (copyout(pr->pagetable, addr, m->head, len) == -1) {
mbuffree(m);
return -1;
}
mbuffree(m);
return len;
}
int
sockwrite(struct sock *si, uint64 addr, int n)
{
struct proc *pr = myproc();
struct mbuf *m;
m = mbufalloc(MBUF_DEFAULT_HEADROOM);
if (!m)
return -1;
if (copyin(pr->pagetable, mbufput(m, n), addr, n) == -1) {
mbuffree(m);
return -1;
}
net_tx_udp(m, si->raddr, si->lport, si->rport);
return n;
}
// called by protocol handler layer to deliver UDP packets
void
sockrecvudp(struct mbuf *m, uint32 raddr, uint16 lport, uint16 rport)
{
//
// Find the socket that handles this mbuf and deliver it, waking
// any sleeping reader. Free the mbuf if there are no sockets
// registered to handle it.
//
struct sock *si;
acquire(&lock);
si = sockets;
while (si) {
if (si->raddr == raddr && si->lport == lport && si->rport == rport)
goto found;
si = si->next;
}
release(&lock);
mbuffree(m);
return;
found:
acquire(&si->lock);
mbufq_pushtail(&si->rxq, m);
wakeup(&si->rxq);
release(&si->lock);
release(&lock);
}
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