xemu/slirp/main.h
Ed Swierk df7a86ed73 slirp: Read host DNS config on demand
Currently the qemu user-mode networking stack reads the host DNS
configuration (/etc/resolv.conf or the Windows equivalent) only once
when qemu starts.  This causes name lookups in the guest to fail if the
host is moved to a different network from which the original DNS servers
are unreachable, a common occurrence when the host is a laptop.

This patch changes the slirp code to read the host DNS configuration on
demand, caching the results for at most 1 second to avoid unnecessary
overhead if name lookups occur in rapid succession.  On non-Windows
hosts, /etc/resolv.conf is re-read only if the file has been replaced or
if its size or mtime has changed.

Signed-off-by: Ed Swierk <eswierk@aristanetworks.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-08-27 20:46:58 -05:00

47 lines
1.1 KiB
C

/*
* Copyright (c) 1995 Danny Gasparovski.
*
* Please read the file COPYRIGHT for the
* terms and conditions of the copyright.
*/
#ifdef HAVE_SYS_SELECT_H
#include <sys/select.h>
#endif
#define TOWRITEMAX 512
extern int slirp_socket;
extern int slirp_socket_unit;
extern int slirp_socket_port;
extern u_int32_t slirp_socket_addr;
extern char *slirp_socket_passwd;
extern int ctty_closed;
/*
* Get the difference in 2 times from updtim()
* Allow for wraparound times, "just in case"
* x is the greater of the 2 (current time) and y is
* what it's being compared against.
*/
#define TIME_DIFF(x,y) (x)-(y) < 0 ? ~0-(y)+(x) : (x)-(y)
extern char *slirp_tty;
extern char *exec_shell;
extern u_int curtime;
extern fd_set *global_readfds, *global_writefds, *global_xfds;
extern struct in_addr loopback_addr;
extern char *username;
extern char *socket_path;
extern int towrite_max;
extern int ppp_exit;
extern int tcp_keepintvl;
#define PROTO_SLIP 0x1
#ifdef USE_PPP
#define PROTO_PPP 0x2
#endif
void if_encap(Slirp *slirp, const uint8_t *ip_data, int ip_data_len);
ssize_t slirp_send(struct socket *so, const void *buf, size_t len, int flags);