void
fpcheck(void)
{
register int fperrval;
char *errdesc;
if ((fperrval = iserr()) == 0)
return; /* no error */
errdesc = (char *) 0;
if (fperrval & INFNAN)
errdesc = "arg is infinity or NAN";
else if (fperrval & ZERODIV)
errdesc = "division by zero";
else if (fperrval & OVFLOW)
errdesc = "overflow";
else if (fperrval & UFLOW) {
; /* ignored */
}
if (errdesc)
rt_error("%s", errdesc);
}
// Runs the interactive loop and all file transfers.
// Returns: exit status
int main(void)
{
// Used to control DNS resolution requests:
struct addrinfo hints;
memset(&hints, 0, sizeof hints);
hints.ai_family = AF_INET;
hints.ai_socktype = SOCK_DGRAM;
// Bind to an ephemeral network port:
struct addrinfo *server = NULL;
int sfd = openudp(0);
if(sfd < 0)
handle_error("bind()");
// Allocate (small) space to store user input:
char *buf = malloc(1);
size_t cap = 1;
char *cmd; // First word of buf
size_t len; // Length of cmd
// Main input loop, which normally only breaks upon a GFO:
do
{
// Keep prompting until the user brings us back something good:
do
{
printf("%s", SHL_PS1);
readin(&buf, &cap);
}
while(homog(buf, ' '));
// Cleave off the command (first word):
cmd = strtok(buf, " ");
len = strlen(cmd);
if(strncmp(cmd, CMD_CON, len) == 0)
{
// Read the arguments:
const char *hostname = strtok(NULL, " ");
const char *tmp = strtok(NULL, " ");
in_port_t port = PORT_UNPRIVILEGED;
if(tmp)
port = atoi(tmp);
// Ensure a hostname or IP has been provided:
if(!hostname)
{
usage(CMD_CON, "hostname", "port");
continue;
}
// Avoid leaking any existing address:
if(server)
{
freeaddrinfo(server);
server = NULL;
}
// Try to resolve the requested hostname:
if(getaddrinfo(hostname, NULL, &hints, &server))
{
fprintf(stderr, "Unable to resolve hostname\n");
freeaddrinfo(server);
server = NULL;
continue;
}
((struct sockaddr_in *)server->ai_addr)->sin_port = htons(port);
}
else if(strncmp(cmd, CMD_GET, len) == 0 || strncmp(cmd, CMD_PUT, len) == 0)
{
bool putting = strncmp(cmd, CMD_PUT, 1) == 0;
// Ensure we're already connected to a server:
if(!server)
{
noconn(cmd);
continue;
}
// Make sure we were given a path argument:
char *pathname = strtok(NULL, "");
if(!pathname)
{
usage(putting ? CMD_PUT : CMD_GET, "pathname", NULL);
continue;
}
// Since basename() might modify pathname, copy it:
char filename[strlen(pathname)+1];
memcpy(filename, pathname, sizeof filename);
int fd;
if(putting)
{
// Try opening the file for reading:
if((fd = open(pathname, O_RDONLY)) < 0)
{
fprintf(stderr, "local: Unable to read specified file\n");
continue;
}
// Send a request and record the port used to acknowledge:
struct sockaddr_in dest_addr;
sendreq(sfd, basename(filename), OPC_WRQ, server->ai_addr);
uint8_t *rmtack = recvpkta(sfd, &dest_addr);
if(iserr(rmtack))
{
fprintf(stderr, "remote: %s\n", strerr(rmtack));
free(rmtack);
continue;
}
free(rmtack);
// Transmit the file:
sendfile(sfd, fd, &dest_addr);
}
else // getting
{
// Try opening a file of that name for writing:
if((fd = open(basename(filename), O_WRONLY|O_CREAT|O_EXCL, 0666)) < 0)
{
fprintf(stderr, "local: Unable to create the new file\n");
continue;
}
// Send a request and await the incoming file:
sendreq(sfd, pathname, OPC_RRQ, server->ai_addr);
const char *res = recvfile(sfd, fd);
if(res)
{
fprintf(stderr, "remote: %s\n", res);
close(fd);
fd = -1;
unlink(basename(filename));
}
}
if(fd >= 0)
close(fd);
}
else if(strncmp(cmd, CMD_HLP, len) == 0)
{
printf("Commands may be abbreviated. Commands are:\n\n");
printf("%s\t\tconnect to remote tftp\n", CMD_CON);
printf("%s\t\tsend file\n", CMD_PUT);
printf("%s\t\treceive file\n", CMD_GET);
printf("%s\t\texit tftp\n", CMD_GFO);
printf("%s\t\tprint help information\n", CMD_HLP);
}
else if(strncmp(cmd, CMD_GFO, len) != 0)
{
fprintf(stderr, "%s: unknown directive\n", cmd);
fprintf(stderr, "Try ? for help.\n");
}
}
while(strncmp(cmd, CMD_GFO, len) != 0);
free(buf);
if(server)
freeaddrinfo(server);
return 0;
}
