/*
* call up the connection server and get a translation
*/
static int nettrans(char *addr, char *naddr, int na, char *file, int nf)
{
int i, fd;
char buf[Maxpath];
char netdir[NETPATHLEN];
char *p, *p2;
long n;
/*
* parse, get network directory
*/
p = strchr(addr, '!');
if (p == 0) {
set_errstr("bad dial string: %s", addr);
return -1;
}
if (*addr != '/') {
strlcpy(netdir, "/net", sizeof(netdir));
} else {
for (p2 = p; *p2 != '/'; p2--) ;
i = p2 - addr;
if (i == 0 || i >= sizeof(netdir)) {
set_errstr("bad dial string: %s", addr);
return -1;
}
strlcpy(netdir, addr, i + 1);
addr = p2 + 1;
}
/*
* ask the connection server
*/
snprintf(buf, sizeof(buf), "%s/cs", netdir);
fd = sysopen(buf, O_RDWR);
if (fd < 0)
return identtrans(netdir, addr, naddr, na, file, nf);
if (syswrite(fd, addr, strlen(addr)) < 0) {
sysclose(fd);
return -1;
}
sysseek(fd, 0, 0);
n = sysread(fd, buf, sizeof(buf) - 1);
sysclose(fd);
if (n <= 0)
return -1;
buf[n] = 0;
/*
* parse the reply
*/
p = strchr(buf, ' ');
if (p == 0)
return -1;
*p++ = 0;
strlcpy(naddr, p, na);
strlcpy(file, buf, nf);
return 0;
}
static void
syscall_handler (struct intr_frame* frame)
{
// -------- System Call Handler Overview --------
// Get system call number
// switch statement using system call number
// collect arguments for system call function if necessary
// call system call function
// set frame->eax to return value if necessary
// ----------------------------------------------
uintptr_t* kpaddr_sp = (uintptr_t*) frame->esp;
int syscall_num = -1;
if(check_uptr(kpaddr_sp))
syscall_num = next_value(&kpaddr_sp);
else
sysexit(-1);
switch(syscall_num)
{
case SYS_HALT:
{
// Terminates Pintos
shutdown_power_off();
}
break;
case SYS_EXIT:
{
uintptr_t status = -1;
if(check_uptr(kpaddr_sp))
status = next_value(&kpaddr_sp);
sysexit(status);
}
break;
case SYS_EXEC: //pid_t exec (const char *file);
{
const char* file = next_charptr(&kpaddr_sp);
if(file == NULL)
sysexit(-1);
unsigned len = strlen(file);
if(!check_buffer(file, len))
sysexit(-1);
else
sysexec(frame, file);
}
break;
case SYS_WAIT: //int wait (pid_t);
{
uintptr_t childid = -1;
if(check_uptr(kpaddr_sp))
childid = next_value(&kpaddr_sp);
else
sysexit(childid);
int retval = process_wait((tid_t) childid);
frame->eax = retval;
}
break;
case SYS_CREATE: //bool create (const char *file, unsigned initial_size);
{
const char* file = next_charptr(&kpaddr_sp);
if(file == NULL)
sysexit(-1);
unsigned len = strlen(file);
if(!check_buffer(file, len))
sysexit(-1);
uintptr_t size = 0;
if(check_uptr(kpaddr_sp))
size = next_value(&kpaddr_sp);
else
sysexit(-1);
syscreate(frame, file, size);
}
break;
case SYS_REMOVE: //bool remove (const char *file);
{
const char* file = next_charptr(&kpaddr_sp);
if(file == NULL)
sysexit(-1);
unsigned len = strlen(file);
if(!check_buffer(file, len))
sysexit(-1);
sysremove(frame, file);
}
break;
case SYS_OPEN:
{
//int open (const char *file);
const char* file = next_charptr(&kpaddr_sp);
if(file == NULL)
sysexit(-1);
unsigned len = strlen(file);
if(!check_buffer(file, len))
sysexit(-1);
sysopen(frame, file);
}
break;
case SYS_FILESIZE:
{
//int filesize (int fd);
int fd = 0;
if (check_uptr(kpaddr_sp))
fd = (int) next_value(&kpaddr_sp);
else
sysexit(-1);
sysfilesize(frame, fd);
}
break;
case SYS_READ:
{
//int read (int fd, void *buffer, unsigned length);
int fd = 0;
if (check_uptr(kpaddr_sp))
fd = (int) next_value(&kpaddr_sp);
else
sysexit(-1);
const char* file = next_charptr(&kpaddr_sp);
if(file == NULL)
sysexit(-1);
unsigned len = strlen(file);
if(!check_buffer(file, len))
sysexit(-1);
unsigned length = 0;
if (check_uptr(kpaddr_sp))
length = (unsigned) next_value(&kpaddr_sp);
else
sysexit(-1);
sysread(frame, fd, (void*) file, length);
}
break;
case SYS_WRITE:
{
//int write (int fd, const void *buffer, unsigned length);
uintptr_t fd = 0;
if(check_uptr(kpaddr_sp))
fd = next_value(&kpaddr_sp);
else
sysexit(-1);
const char* file = next_charptr(&kpaddr_sp);
if(file == NULL)
sysexit(-1);
unsigned len = strlen(file);
if(!check_buffer(file, len))
sysexit(-1);
uintptr_t length = 0;
if(check_uptr(kpaddr_sp))
length = next_value(&kpaddr_sp);
else
sysexit(-1);
if(fd == CONSOLEWRITE) // Write to Console
{
while(length > 0)
{
if(length > MAX_SIZE)
{
putbuf (file, MAX_SIZE);
file += MAX_SIZE;
length -= MAX_SIZE;
}
else
{
putbuf (file, length);
length = 0;
}
}
}
else
{
syswrite(frame, fd, file, length);
}
}
break;
case SYS_SEEK:
{
//void seek (int fd, unsigned position);
int fd = 0;
if (check_uptr(kpaddr_sp))
fd = (int) next_value(&kpaddr_sp);
else
sysexit(-1);
unsigned position = 0;
if (check_uptr(kpaddr_sp))
position = (unsigned) next_value(&kpaddr_sp);
else
sysexit(-1);
sysseek(fd, position);
}
break;
case SYS_TELL:
{
//unsigned tell (int fd);
int fd = 0;
if (check_uptr(kpaddr_sp))
fd = (int) next_value(&kpaddr_sp);
else
sysexit(-1);
systell(frame, fd);
}
break;
case SYS_CLOSE:
{
//void close (int fd);
int fd = 0;
if (check_uptr(kpaddr_sp))
fd = (int) next_value(&kpaddr_sp);
else
sysexit(-1);
sysclose(fd);
}
break;
default:
{
printf("Unrecognized System Call\n");
sysexit(-1);
}
break;
}
}
static int csdial(DS * ds)
{
int n, fd, rv = -1;
char *p, *buf, *clone, *err, *besterr;
buf = kmalloc(Maxstring, KMALLOC_WAIT);
clone = kmalloc(Maxpath, KMALLOC_WAIT);
err = kmalloc(ERRMAX, KMALLOC_WAIT);
besterr = kmalloc(ERRMAX, KMALLOC_WAIT);
/*
* open connection server
*/
snprintf(buf, Maxstring, "%s/cs", ds->netdir);
fd = sysopen(buf, O_RDWR);
if (fd < 0) {
/* no connection server, don't translate */
snprintf(clone, Maxpath, "%s/%s/clone", ds->netdir, ds->proto);
rv = call(clone, ds->rem, ds);
goto out;
}
/*
* ask connection server to translate
*/
snprintf(buf, Maxstring, "%s!%s", ds->proto, ds->rem);
if (syswrite(fd, buf, strlen(buf)) < 0) {
kerrstr(err, ERRMAX);
sysclose(fd);
set_errstr("%s (%s)", err, buf);
goto out;
}
/*
* loop through each address from the connection server till
* we get one that works.
*/
*besterr = 0;
strlcpy(err, errno_to_string(ECONNRESET), ERRMAX);
sysseek(fd, 0, 0);
while ((n = sysread(fd, buf, Maxstring - 1)) > 0) {
buf[n] = 0;
p = strchr(buf, ' ');
if (p == 0)
continue;
*p++ = 0;
rv = call(buf, p, ds);
if (rv >= 0)
break;
err[0] = 0;
kerrstr(err, ERRMAX);
if (strstr(err, "does not exist") == 0)
memmove(besterr, err, ERRMAX);
}
sysclose(fd);
if (rv < 0 && *besterr)
kerrstr(besterr, ERRMAX);
else
kerrstr(err, ERRMAX);
out:
kfree(buf);
kfree(clone);
kfree(err);
kfree(besterr);
return rv;
}
