qemu/slirp/misc.c

424 lines
10 KiB
C
Raw Normal View History

/*
* Copyright (c) 1995 Danny Gasparovski.
*
* Please read the file COPYRIGHT for the
* terms and conditions of the copyright.
*/
#include <slirp.h>
#include <libslirp.h>
#include "monitor.h"
#ifdef DEBUG
int slirp_debug = DBG_CALL|DBG_MISC|DBG_ERROR;
#endif
struct quehead {
struct quehead *qh_link;
struct quehead *qh_rlink;
};
inline void
insque(void *a, void *b)
{
register struct quehead *element = (struct quehead *) a;
register struct quehead *head = (struct quehead *) b;
element->qh_link = head->qh_link;
head->qh_link = (struct quehead *)element;
element->qh_rlink = (struct quehead *)head;
((struct quehead *)(element->qh_link))->qh_rlink
= (struct quehead *)element;
}
inline void
remque(void *a)
{
register struct quehead *element = (struct quehead *) a;
((struct quehead *)(element->qh_link))->qh_rlink = element->qh_rlink;
((struct quehead *)(element->qh_rlink))->qh_link = element->qh_link;
element->qh_rlink = NULL;
}
int add_exec(struct ex_list **ex_ptr, int do_pty, char *exec,
struct in_addr addr, int port)
{
struct ex_list *tmp_ptr;
/* First, check if the port is "bound" */
for (tmp_ptr = *ex_ptr; tmp_ptr; tmp_ptr = tmp_ptr->ex_next) {
if (port == tmp_ptr->ex_fport &&
addr.s_addr == tmp_ptr->ex_addr.s_addr)
return -1;
}
tmp_ptr = *ex_ptr;
*ex_ptr = (struct ex_list *)malloc(sizeof(struct ex_list));
(*ex_ptr)->ex_fport = port;
(*ex_ptr)->ex_addr = addr;
(*ex_ptr)->ex_pty = do_pty;
(*ex_ptr)->ex_exec = (do_pty == 3) ? exec : strdup(exec);
(*ex_ptr)->ex_next = tmp_ptr;
return 0;
}
#ifndef HAVE_STRERROR
/*
* For systems with no strerror
*/
extern int sys_nerr;
extern char *sys_errlist[];
char *
strerror(error)
int error;
{
if (error < sys_nerr)
return sys_errlist[error];
else
return "Unknown error.";
}
#endif
#ifdef _WIN32
int
fork_exec(struct socket *so, const char *ex, int do_pty)
{
/* not implemented */
return 0;
}
#else
/*
* XXX This is ugly
* We create and bind a socket, then fork off to another
* process, which connects to this socket, after which we
* exec the wanted program. If something (strange) happens,
* the accept() call could block us forever.
*
* do_pty = 0 Fork/exec inetd style
* do_pty = 1 Fork/exec using slirp.telnetd
* do_ptr = 2 Fork/exec using pty
*/
int
fork_exec(struct socket *so, const char *ex, int do_pty)
{
int s;
struct sockaddr_in addr;
socklen_t addrlen = sizeof(addr);
int opt;
int master = -1;
const char *argv[256];
/* don't want to clobber the original */
char *bptr;
const char *curarg;
int c, i, ret;
pid_t pid;
DEBUG_CALL("fork_exec");
DEBUG_ARG("so = %lx", (long)so);
DEBUG_ARG("ex = %lx", (long)ex);
DEBUG_ARG("do_pty = %lx", (long)do_pty);
if (do_pty == 2) {
return 0;
} else {
addr.sin_family = AF_INET;
addr.sin_port = 0;
addr.sin_addr.s_addr = INADDR_ANY;
if ((s = qemu_socket(AF_INET, SOCK_STREAM, 0)) < 0 ||
bind(s, (struct sockaddr *)&addr, addrlen) < 0 ||
listen(s, 1) < 0) {
lprint("Error: inet socket: %s\n", strerror(errno));
closesocket(s);
return 0;
}
}
pid = fork();
switch(pid) {
case -1:
lprint("Error: fork failed: %s\n", strerror(errno));
close(s);
if (do_pty == 2)
close(master);
return 0;
case 0:
setsid();
/* Set the DISPLAY */
if (do_pty == 2) {
(void) close(master);
#ifdef TIOCSCTTY /* XXXXX */
ioctl(s, TIOCSCTTY, (char *)NULL);
#endif
} else {
getsockname(s, (struct sockaddr *)&addr, &addrlen);
close(s);
/*
* Connect to the socket
* XXX If any of these fail, we're in trouble!
*/
s = qemu_socket(AF_INET, SOCK_STREAM, 0);
addr.sin_addr = loopback_addr;
do {
ret = connect(s, (struct sockaddr *)&addr, addrlen);
} while (ret < 0 && errno == EINTR);
}
dup2(s, 0);
dup2(s, 1);
dup2(s, 2);
for (s = getdtablesize() - 1; s >= 3; s--)
close(s);
i = 0;
don't dereference NULL after failed strdup Most of these are obvious NULL-deref bug fixes, for example, the ones in these files: block/curl.c net.c slirp/misc.c and the first one in block/vvfat.c. The others in block/vvfat.c may not lead to an immediate segfault, but I traced the two schedule_rename(..., strdup(path)) uses, and a failed strdup would appear to trigger this assertion in handle_renames_and_mkdirs: assert(commit->path); The conversion to use qemu_strdup in envlist_to_environ is not technically needed, but does avoid a theoretical leak in the caller when strdup fails for one value, but later succeeds in allocating another buffer(plausible, if one string length is much larger than the others). The caller does not know the length of the returned list, and as such can only free pointers until it hits the first NULL. If there are non-NULL pointers beyond the first, their buffers would be leaked. This one is admittedly far-fetched. The two in linux-user/main.c are worth fixing to ensure that an OOM error is diagnosed up front, rather than letting it provoke some harder-to-diagnose secondary error, in case of exec failure, or worse, in case the exec succeeds but with an invalid list of command line options. However, considering how unlikely it is to encounter a failed strdup early in main, this isn't a big deal. Note that adding the required uses of qemu_strdup here and in envlist.c induce link failures because qemu_strdup is not currently in any library they're linked with. So for now, I've omitted those changes, as well as the fixes in target-i386/helper.c and target-sparc/helper.c. If you'd like to see the above discussion (or anything else) in the commit log, just let me know and I'll be happy to adjust. >From 9af42864fd1ea666bd25e2cecfdfae74c20aa8c7 Mon Sep 17 00:00:00 2001 From: Jim Meyering <meyering@redhat.com> Date: Mon, 8 Feb 2010 18:29:29 +0100 Subject: [PATCH] don't dereference NULL after failed strdup Handle failing strdup by replacing each use with qemu_strdup, so as not to dereference NULL or trigger a failing assertion. * block/curl.c (curl_open): s/\bstrdup\b/qemu_strdup/ * block/vvfat.c (init_directories): Likewise. (get_cluster_count_for_direntry, check_directory_consistency): Likewise. * net.c (parse_host_src_port): Likewise. * slirp/misc.c (fork_exec): Likewise. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-02-08 21:28:38 +03:00
bptr = qemu_strdup(ex); /* No need to free() this */
if (do_pty == 1) {
/* Setup "slirp.telnetd -x" */
argv[i++] = "slirp.telnetd";
argv[i++] = "-x";
argv[i++] = bptr;
} else
do {
/* Change the string into argv[] */
curarg = bptr;
while (*bptr != ' ' && *bptr != (char)0)
bptr++;
c = *bptr;
*bptr++ = (char)0;
argv[i++] = strdup(curarg);
} while (c);
argv[i] = NULL;
execvp(argv[0], (char **)argv);
/* Ooops, failed, let's tell the user why */
fprintf(stderr, "Error: execvp of %s failed: %s\n",
argv[0], strerror(errno));
close(0); close(1); close(2); /* XXX */
exit(1);
default:
qemu_add_child_watch(pid);
if (do_pty == 2) {
close(s);
so->s = master;
} else {
/*
* XXX this could block us...
* XXX Should set a timer here, and if accept() doesn't
* return after X seconds, declare it a failure
* The only reason this will block forever is if socket()
* of connect() fail in the child process
*/
do {
so->s = accept(s, (struct sockaddr *)&addr, &addrlen);
} while (so->s < 0 && errno == EINTR);
closesocket(s);
opt = 1;
setsockopt(so->s,SOL_SOCKET,SO_REUSEADDR,(char *)&opt,sizeof(int));
opt = 1;
setsockopt(so->s,SOL_SOCKET,SO_OOBINLINE,(char *)&opt,sizeof(int));
}
fd_nonblock(so->s);
/* Append the telnet options now */
if (so->so_m != NULL && do_pty == 1) {
sbappend(so, so->so_m);
so->so_m = NULL;
}
return 1;
}
}
#endif
#ifndef HAVE_STRDUP
char *
strdup(str)
const char *str;
{
char *bptr;
bptr = (char *)malloc(strlen(str)+1);
strcpy(bptr, str);
return bptr;
}
#endif
#include "monitor.h"
void lprint(const char *format, ...)
{
va_list args;
va_start(args, format);
monitor: Separate "default monitor" and "current monitor" cleanly Commits 376253ec..731b0364 introduced global variable cur_mon, which points to the "default monitor" (if any), except during execution of monitor_read() or monitor_control_read() it points to the monitor from which we're reading instead (the "current monitor"). Monitor command handlers run within monitor_read() or monitor_control_read(). Default monitor and current monitor are really separate things, and squashing them together is confusing and error-prone. For instance, usb_host_scan() can run both in "info usbhost" and periodically via usb_host_auto_check(). It prints to cur_mon, which is what we want in the former case: the monitor executing "info usbhost". But since that's the default monitor in the latter case, it periodically spams the default monitor there. A few places use cur_mon to log stuff to the default monitor. If we ever log something while cur_mon points to current monitor instead of default monitor, the log temporarily "jumps" to another monitor. Whether that can or cannot happen isn't always obvious. Maybe logging to the default monitor (which may not even exist) is a bad idea, and we should log to stderr or a logfile instead. But that's outside the scope of this commit. Change cur_mon to point to the current monitor. Create new default_mon to point to the default monitor. Update users of cur_mon accordingly. This fixes the periodical spamming of the default monitor by usb_host_scan(). It also stops "log jumping", should that problem exist.
2010-02-18 13:41:55 +03:00
monitor_vprintf(default_mon, format, args);
va_end(args);
}
void
u_sleep(int usec)
{
struct timeval t;
fd_set fdset;
FD_ZERO(&fdset);
t.tv_sec = 0;
t.tv_usec = usec * 1000;
select(0, &fdset, &fdset, &fdset, &t);
}
/*
* Set fd blocking and non-blocking
*/
void
fd_nonblock(int fd)
{
#ifdef FIONBIO
#ifdef _WIN32
unsigned long opt = 1;
#else
int opt = 1;
#endif
ioctlsocket(fd, FIONBIO, &opt);
#else
int opt;
opt = fcntl(fd, F_GETFL, 0);
opt |= O_NONBLOCK;
fcntl(fd, F_SETFL, opt);
#endif
}
void
fd_block(int fd)
{
#ifdef FIONBIO
#ifdef _WIN32
unsigned long opt = 0;
#else
int opt = 0;
#endif
ioctlsocket(fd, FIONBIO, &opt);
#else
int opt;
opt = fcntl(fd, F_GETFL, 0);
opt &= ~O_NONBLOCK;
fcntl(fd, F_SETFL, opt);
#endif
}
void slirp_connection_info(Slirp *slirp, Monitor *mon)
{
const char * const tcpstates[] = {
[TCPS_CLOSED] = "CLOSED",
[TCPS_LISTEN] = "LISTEN",
[TCPS_SYN_SENT] = "SYN_SENT",
[TCPS_SYN_RECEIVED] = "SYN_RCVD",
[TCPS_ESTABLISHED] = "ESTABLISHED",
[TCPS_CLOSE_WAIT] = "CLOSE_WAIT",
[TCPS_FIN_WAIT_1] = "FIN_WAIT_1",
[TCPS_CLOSING] = "CLOSING",
[TCPS_LAST_ACK] = "LAST_ACK",
[TCPS_FIN_WAIT_2] = "FIN_WAIT_2",
[TCPS_TIME_WAIT] = "TIME_WAIT",
};
struct in_addr dst_addr;
struct sockaddr_in src;
socklen_t src_len;
uint16_t dst_port;
struct socket *so;
const char *state;
char buf[20];
int n;
monitor_printf(mon, " Protocol[State] FD Source Address Port "
"Dest. Address Port RecvQ SendQ\n");
for (so = slirp->tcb.so_next; so != &slirp->tcb; so = so->so_next) {
if (so->so_state & SS_HOSTFWD) {
state = "HOST_FORWARD";
} else if (so->so_tcpcb) {
state = tcpstates[so->so_tcpcb->t_state];
} else {
state = "NONE";
}
if (so->so_state & (SS_HOSTFWD | SS_INCOMING)) {
src_len = sizeof(src);
getsockname(so->s, (struct sockaddr *)&src, &src_len);
dst_addr = so->so_laddr;
dst_port = so->so_lport;
} else {
src.sin_addr = so->so_laddr;
src.sin_port = so->so_lport;
dst_addr = so->so_faddr;
dst_port = so->so_fport;
}
n = snprintf(buf, sizeof(buf), " TCP[%s]", state);
memset(&buf[n], ' ', 19 - n);
buf[19] = 0;
monitor_printf(mon, "%s %3d %15s %5d ", buf, so->s,
src.sin_addr.s_addr ? inet_ntoa(src.sin_addr) : "*",
ntohs(src.sin_port));
monitor_printf(mon, "%15s %5d %5d %5d\n",
inet_ntoa(dst_addr), ntohs(dst_port),
so->so_rcv.sb_cc, so->so_snd.sb_cc);
}
for (so = slirp->udb.so_next; so != &slirp->udb; so = so->so_next) {
if (so->so_state & SS_HOSTFWD) {
n = snprintf(buf, sizeof(buf), " UDP[HOST_FORWARD]");
src_len = sizeof(src);
getsockname(so->s, (struct sockaddr *)&src, &src_len);
dst_addr = so->so_laddr;
dst_port = so->so_lport;
} else {
n = snprintf(buf, sizeof(buf), " UDP[%d sec]",
(so->so_expire - curtime) / 1000);
src.sin_addr = so->so_laddr;
src.sin_port = so->so_lport;
dst_addr = so->so_faddr;
dst_port = so->so_fport;
}
memset(&buf[n], ' ', 19 - n);
buf[19] = 0;
monitor_printf(mon, "%s %3d %15s %5d ", buf, so->s,
src.sin_addr.s_addr ? inet_ntoa(src.sin_addr) : "*",
ntohs(src.sin_port));
monitor_printf(mon, "%15s %5d %5d %5d\n",
inet_ntoa(dst_addr), ntohs(dst_port),
so->so_rcv.sb_cc, so->so_snd.sb_cc);
}
for (so = slirp->icmp.so_next; so != &slirp->icmp; so = so->so_next) {
n = snprintf(buf, sizeof(buf), " ICMP[%d sec]",
(so->so_expire - curtime) / 1000);
src.sin_addr = so->so_laddr;
dst_addr = so->so_faddr;
memset(&buf[n], ' ', 19 - n);
buf[19] = 0;
monitor_printf(mon, "%s %3d %15s - ", buf, so->s,
src.sin_addr.s_addr ? inet_ntoa(src.sin_addr) : "*");
monitor_printf(mon, "%15s - %5d %5d\n", inet_ntoa(dst_addr),
so->so_rcv.sb_cc, so->so_snd.sb_cc);
}
}