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qemu/net/slirp.c
Markus Armbruster e30e5eb613 slirp: Clean up net_slirp_hostfwd_remove()'s use of get_str_sep() 
get_str_sep() can fail, but net_slirp_hostfwd_remove() doesn't check.
Works, because it initializes buf[] to "", which get_str_sep() doesn't
touch when it fails.  Coverity doesn't like it, and neither do I.

Change it to work exactly like slirp_hostfwd().

Acked-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-11-22 11:11:23 +00:00

779 lines
22 KiB
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/*
* QEMU System Emulator
*
* Copyright (c) 2003-2008 Fabrice Bellard
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "net/slirp.h"
#include "config-host.h"
#ifndef _WIN32
#include <sys/wait.h>
#endif
#include "net.h"
#include "monitor.h"
#include "qemu_socket.h"
#include "slirp/libslirp.h"
static int get_str_sep(char *buf, int buf_size, const char **pp, int sep)
{
const char *p, *p1;
int len;
p = *pp;
p1 = strchr(p, sep);
if (!p1)
return -1;
len = p1 - p;
p1++;
if (buf_size > 0) {
if (len > buf_size - 1)
len = buf_size - 1;
memcpy(buf, p, len);
buf[len] = '\0';
}
*pp = p1;
return 0;
}
/* slirp network adapter */
#define SLIRP_CFG_HOSTFWD 1
#define SLIRP_CFG_LEGACY 2
struct slirp_config_str {
struct slirp_config_str *next;
int flags;
char str[1024];
int legacy_format;
};
typedef struct SlirpState {
VLANClientState nc;
QTAILQ_ENTRY(SlirpState) entry;
Slirp *slirp;
#ifndef _WIN32
char smb_dir[128];
#endif
} SlirpState;
static struct slirp_config_str *slirp_configs;
const char *legacy_tftp_prefix;
const char *legacy_bootp_filename;
static QTAILQ_HEAD(slirp_stacks, SlirpState) slirp_stacks =
QTAILQ_HEAD_INITIALIZER(slirp_stacks);
static int slirp_hostfwd(SlirpState *s, const char *redir_str,
int legacy_format);
static int slirp_guestfwd(SlirpState *s, const char *config_str,
int legacy_format);
#ifndef _WIN32
static const char *legacy_smb_export;
static int slirp_smb(SlirpState *s, const char *exported_dir,
struct in_addr vserver_addr);
static void slirp_smb_cleanup(SlirpState *s);
#else
static inline void slirp_smb_cleanup(SlirpState *s) { }
#endif
int slirp_can_output(void *opaque)
{
SlirpState *s = opaque;
return qemu_can_send_packet(&s->nc);
}
void slirp_output(void *opaque, const uint8_t *pkt, int pkt_len)
{
SlirpState *s = opaque;
qemu_send_packet(&s->nc, pkt, pkt_len);
}
static ssize_t net_slirp_receive(VLANClientState *nc, const uint8_t *buf, size_t size)
{
SlirpState *s = DO_UPCAST(SlirpState, nc, nc);
slirp_input(s->slirp, buf, size);
return size;
}
static void net_slirp_cleanup(VLANClientState *nc)
{
SlirpState *s = DO_UPCAST(SlirpState, nc, nc);
slirp_cleanup(s->slirp);
slirp_smb_cleanup(s);
QTAILQ_REMOVE(&slirp_stacks, s, entry);
}
static NetClientInfo net_slirp_info = {
.type = NET_CLIENT_TYPE_USER,
.size = sizeof(SlirpState),
.receive = net_slirp_receive,
.cleanup = net_slirp_cleanup,
};
static int net_slirp_init(VLANState *vlan, const char *model,
const char *name, int restricted,
const char *vnetwork, const char *vhost,
const char *vhostname, const char *tftp_export,
const char *bootfile, const char *vdhcp_start,
const char *vnameserver, const char *smb_export,
const char *vsmbserver)
{
/* default settings according to historic slirp */
struct in_addr net = { .s_addr = htonl(0x0a000200) }; /* 10.0.2.0 */
struct in_addr mask = { .s_addr = htonl(0xffffff00) }; /* 255.255.255.0 */
struct in_addr host = { .s_addr = htonl(0x0a000202) }; /* 10.0.2.2 */
struct in_addr dhcp = { .s_addr = htonl(0x0a00020f) }; /* 10.0.2.15 */
struct in_addr dns = { .s_addr = htonl(0x0a000203) }; /* 10.0.2.3 */
#ifndef _WIN32
struct in_addr smbsrv = { .s_addr = 0 };
#endif
VLANClientState *nc;
SlirpState *s;
char buf[20];
uint32_t addr;
int shift;
char *end;
struct slirp_config_str *config;
if (!tftp_export) {
tftp_export = legacy_tftp_prefix;
}
if (!bootfile) {
bootfile = legacy_bootp_filename;
}
if (vnetwork) {
if (get_str_sep(buf, sizeof(buf), &vnetwork, '/') < 0) {
if (!inet_aton(vnetwork, &net)) {
return -1;
}
addr = ntohl(net.s_addr);
if (!(addr & 0x80000000)) {
mask.s_addr = htonl(0xff000000); /* class A */
} else if ((addr & 0xfff00000) == 0xac100000) {
mask.s_addr = htonl(0xfff00000); /* priv. 172.16.0.0/12 */
} else if ((addr & 0xc0000000) == 0x80000000) {
mask.s_addr = htonl(0xffff0000); /* class B */
} else if ((addr & 0xffff0000) == 0xc0a80000) {
mask.s_addr = htonl(0xffff0000); /* priv. 192.168.0.0/16 */
} else if ((addr & 0xffff0000) == 0xc6120000) {
mask.s_addr = htonl(0xfffe0000); /* tests 198.18.0.0/15 */
} else if ((addr & 0xe0000000) == 0xe0000000) {
mask.s_addr = htonl(0xffffff00); /* class C */
} else {
mask.s_addr = htonl(0xfffffff0); /* multicast/reserved */
}
} else {
if (!inet_aton(buf, &net)) {
return -1;
}
shift = strtol(vnetwork, &end, 10);
if (*end != '\0') {
if (!inet_aton(vnetwork, &mask)) {
return -1;
}
} else if (shift < 4 || shift > 32) {
return -1;
} else {
mask.s_addr = htonl(0xffffffff << (32 - shift));
}
}
net.s_addr &= mask.s_addr;
host.s_addr = net.s_addr | (htonl(0x0202) & ~mask.s_addr);
dhcp.s_addr = net.s_addr | (htonl(0x020f) & ~mask.s_addr);
dns.s_addr = net.s_addr | (htonl(0x0203) & ~mask.s_addr);
}
if (vhost && !inet_aton(vhost, &host)) {
return -1;
}
if ((host.s_addr & mask.s_addr) != net.s_addr) {
return -1;
}
if (vdhcp_start && !inet_aton(vdhcp_start, &dhcp)) {
return -1;
}
if ((dhcp.s_addr & mask.s_addr) != net.s_addr ||
dhcp.s_addr == host.s_addr || dhcp.s_addr == dns.s_addr) {
return -1;
}
if (vnameserver && !inet_aton(vnameserver, &dns)) {
return -1;
}
if ((dns.s_addr & mask.s_addr) != net.s_addr ||
dns.s_addr == host.s_addr) {
return -1;
}
#ifndef _WIN32
if (vsmbserver && !inet_aton(vsmbserver, &smbsrv)) {
return -1;
}
#endif
nc = qemu_new_net_client(&net_slirp_info, vlan, NULL, model, name);
snprintf(nc->info_str, sizeof(nc->info_str),
"net=%s,restrict=%s", inet_ntoa(net),
restricted ? "on" : "off");
s = DO_UPCAST(SlirpState, nc, nc);
s->slirp = slirp_init(restricted, net, mask, host, vhostname,
tftp_export, bootfile, dhcp, dns, s);
QTAILQ_INSERT_TAIL(&slirp_stacks, s, entry);
for (config = slirp_configs; config; config = config->next) {
if (config->flags & SLIRP_CFG_HOSTFWD) {
if (slirp_hostfwd(s, config->str,
config->flags & SLIRP_CFG_LEGACY) < 0)
goto error;
} else {
if (slirp_guestfwd(s, config->str,
config->flags & SLIRP_CFG_LEGACY) < 0)
goto error;
}
}
#ifndef _WIN32
if (!smb_export) {
smb_export = legacy_smb_export;
}
if (smb_export) {
if (slirp_smb(s, smb_export, smbsrv) < 0)
goto error;
}
#endif
return 0;
error:
qemu_del_vlan_client(nc);
return -1;
}
static SlirpState *slirp_lookup(Monitor *mon, const char *vlan,
const char *stack)
{
if (vlan) {
VLANClientState *nc;
nc = qemu_find_vlan_client_by_name(mon, strtol(vlan, NULL, 0), stack);
if (!nc) {
return NULL;
}
if (strcmp(nc->model, "user")) {
monitor_printf(mon, "invalid device specified\n");
return NULL;
}
return DO_UPCAST(SlirpState, nc, nc);
} else {
if (QTAILQ_EMPTY(&slirp_stacks)) {
monitor_printf(mon, "user mode network stack not in use\n");
return NULL;
}
return QTAILQ_FIRST(&slirp_stacks);
}
}
void net_slirp_hostfwd_remove(Monitor *mon, const QDict *qdict)
{
struct in_addr host_addr = { .s_addr = INADDR_ANY };
int host_port;
char buf[256];
const char *src_str, *p;
SlirpState *s;
int is_udp = 0;
int err;
const char *arg1 = qdict_get_str(qdict, "arg1");
const char *arg2 = qdict_get_try_str(qdict, "arg2");
const char *arg3 = qdict_get_try_str(qdict, "arg3");
if (arg2) {
s = slirp_lookup(mon, arg1, arg2);
src_str = arg3;
} else {
s = slirp_lookup(mon, NULL, NULL);
src_str = arg1;
}
if (!s) {
return;
}
p = src_str;
if (!p || get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
goto fail_syntax;
}
if (!strcmp(buf, "tcp") || buf[0] == '\0') {
is_udp = 0;
} else if (!strcmp(buf, "udp")) {
is_udp = 1;
} else {
goto fail_syntax;
}
if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
goto fail_syntax;
}
if (buf[0] != '\0' && !inet_aton(buf, &host_addr)) {
goto fail_syntax;
}
host_port = atoi(p);
err = slirp_remove_hostfwd(QTAILQ_FIRST(&slirp_stacks)->slirp, is_udp,
host_addr, host_port);
monitor_printf(mon, "host forwarding rule for %s %s\n", src_str,
err ? "removed" : "not found");
return;
fail_syntax:
monitor_printf(mon, "invalid format\n");
}
static int slirp_hostfwd(SlirpState *s, const char *redir_str,
int legacy_format)
{
struct in_addr host_addr = { .s_addr = INADDR_ANY };
struct in_addr guest_addr = { .s_addr = 0 };
int host_port, guest_port;
const char *p;
char buf[256];
int is_udp;
char *end;
p = redir_str;
if (!p || get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
goto fail_syntax;
}
if (!strcmp(buf, "tcp") || buf[0] == '\0') {
is_udp = 0;
} else if (!strcmp(buf, "udp")) {
is_udp = 1;
} else {
goto fail_syntax;
}
if (!legacy_format) {
if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
goto fail_syntax;
}
if (buf[0] != '\0' && !inet_aton(buf, &host_addr)) {
goto fail_syntax;
}
}
if (get_str_sep(buf, sizeof(buf), &p, legacy_format ? ':' : '-') < 0) {
goto fail_syntax;
}
host_port = strtol(buf, &end, 0);
if (*end != '\0' || host_port < 1 || host_port > 65535) {
goto fail_syntax;
}
if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
goto fail_syntax;
}
if (buf[0] != '\0' && !inet_aton(buf, &guest_addr)) {
goto fail_syntax;
}
guest_port = strtol(p, &end, 0);
if (*end != '\0' || guest_port < 1 || guest_port > 65535) {
goto fail_syntax;
}
if (slirp_add_hostfwd(s->slirp, is_udp, host_addr, host_port, guest_addr,
guest_port) < 0) {
error_report("could not set up host forwarding rule '%s'",
redir_str);
return -1;
}
return 0;
fail_syntax:
error_report("invalid host forwarding rule '%s'", redir_str);
return -1;
}
void net_slirp_hostfwd_add(Monitor *mon, const QDict *qdict)
{
const char *redir_str;
SlirpState *s;
const char *arg1 = qdict_get_str(qdict, "arg1");
const char *arg2 = qdict_get_try_str(qdict, "arg2");
const char *arg3 = qdict_get_try_str(qdict, "arg3");
if (arg2) {
s = slirp_lookup(mon, arg1, arg2);
redir_str = arg3;
} else {
s = slirp_lookup(mon, NULL, NULL);
redir_str = arg1;
}
if (s) {
slirp_hostfwd(s, redir_str, 0);
}
}
int net_slirp_redir(const char *redir_str)
{
struct slirp_config_str *config;
if (QTAILQ_EMPTY(&slirp_stacks)) {
config = g_malloc(sizeof(*config));
pstrcpy(config->str, sizeof(config->str), redir_str);
config->flags = SLIRP_CFG_HOSTFWD | SLIRP_CFG_LEGACY;
config->next = slirp_configs;
slirp_configs = config;
return 0;
}
return slirp_hostfwd(QTAILQ_FIRST(&slirp_stacks), redir_str, 1);
}
#ifndef _WIN32
/* automatic user mode samba server configuration */
static void slirp_smb_cleanup(SlirpState *s)
{
char cmd[128];
int ret;
if (s->smb_dir[0] != '\0') {
snprintf(cmd, sizeof(cmd), "rm -rf %s", s->smb_dir);
ret = system(cmd);
if (ret == -1 || !WIFEXITED(ret)) {
error_report("'%s' failed.", cmd);
} else if (WEXITSTATUS(ret)) {
error_report("'%s' failed. Error code: %d",
cmd, WEXITSTATUS(ret));
}
s->smb_dir[0] = '\0';
}
}
static int slirp_smb(SlirpState* s, const char *exported_dir,
struct in_addr vserver_addr)
{
static int instance;
char smb_conf[128];
char smb_cmdline[128];
FILE *f;
snprintf(s->smb_dir, sizeof(s->smb_dir), "/tmp/qemu-smb.%ld-%d",
(long)getpid(), instance++);
if (mkdir(s->smb_dir, 0700) < 0) {
error_report("could not create samba server dir '%s'", s->smb_dir);
return -1;
}
snprintf(smb_conf, sizeof(smb_conf), "%s/%s", s->smb_dir, "smb.conf");
f = fopen(smb_conf, "w");
if (!f) {
slirp_smb_cleanup(s);
error_report("could not create samba server configuration file '%s'",
smb_conf);
return -1;
}
fprintf(f,
"[global]\n"
"private dir=%s\n"
"smb ports=0\n"
"socket address=127.0.0.1\n"
"pid directory=%s\n"
"lock directory=%s\n"
"log file=%s/log.smbd\n"
"smb passwd file=%s/smbpasswd\n"
"security = share\n"
"[qemu]\n"
"path=%s\n"
"read only=no\n"
"guest ok=yes\n",
s->smb_dir,
s->smb_dir,
s->smb_dir,
s->smb_dir,
s->smb_dir,
exported_dir
);
fclose(f);
snprintf(smb_cmdline, sizeof(smb_cmdline), "%s -s %s",
CONFIG_SMBD_COMMAND, smb_conf);
if (slirp_add_exec(s->slirp, 0, smb_cmdline, &vserver_addr, 139) < 0) {
slirp_smb_cleanup(s);
error_report("conflicting/invalid smbserver address");
return -1;
}
return 0;
}
/* automatic user mode samba server configuration (legacy interface) */
int net_slirp_smb(const char *exported_dir)
{
struct in_addr vserver_addr = { .s_addr = 0 };
if (legacy_smb_export) {
fprintf(stderr, "-smb given twice\n");
return -1;
}
legacy_smb_export = exported_dir;
if (!QTAILQ_EMPTY(&slirp_stacks)) {
return slirp_smb(QTAILQ_FIRST(&slirp_stacks), exported_dir,
vserver_addr);
}
return 0;
}
#endif /* !defined(_WIN32) */
struct GuestFwd {
CharDriverState *hd;
struct in_addr server;
int port;
Slirp *slirp;
};
static int guestfwd_can_read(void *opaque)
{
struct GuestFwd *fwd = opaque;
return slirp_socket_can_recv(fwd->slirp, fwd->server, fwd->port);
}
static void guestfwd_read(void *opaque, const uint8_t *buf, int size)
{
struct GuestFwd *fwd = opaque;
slirp_socket_recv(fwd->slirp, fwd->server, fwd->port, buf, size);
}
static int slirp_guestfwd(SlirpState *s, const char *config_str,
int legacy_format)
{
struct in_addr server = { .s_addr = 0 };
struct GuestFwd *fwd;
const char *p;
char buf[128];
char *end;
int port;
p = config_str;
if (legacy_format) {
if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
goto fail_syntax;
}
} else {
if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
goto fail_syntax;
}
if (strcmp(buf, "tcp") && buf[0] != '\0') {
goto fail_syntax;
}
if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
goto fail_syntax;
}
if (buf[0] != '\0' && !inet_aton(buf, &server)) {
goto fail_syntax;
}
if (get_str_sep(buf, sizeof(buf), &p, '-') < 0) {
goto fail_syntax;
}
}
port = strtol(buf, &end, 10);
if (*end != '\0' || port < 1 || port > 65535) {
goto fail_syntax;
}
fwd = g_malloc(sizeof(struct GuestFwd));
snprintf(buf, sizeof(buf), "guestfwd.tcp.%d", port);
fwd->hd = qemu_chr_new(buf, p, NULL);
if (!fwd->hd) {
error_report("could not open guest forwarding device '%s'", buf);
g_free(fwd);
return -1;
}
if (slirp_add_exec(s->slirp, 3, fwd->hd, &server, port) < 0) {
error_report("conflicting/invalid host:port in guest forwarding "
"rule '%s'", config_str);
g_free(fwd);
return -1;
}
fwd->server = server;
fwd->port = port;
fwd->slirp = s->slirp;
qemu_chr_add_handlers(fwd->hd, guestfwd_can_read, guestfwd_read,
NULL, fwd);
return 0;
fail_syntax:
error_report("invalid guest forwarding rule '%s'", config_str);
return -1;
}
void do_info_usernet(Monitor *mon)
{
SlirpState *s;
QTAILQ_FOREACH(s, &slirp_stacks, entry) {
monitor_printf(mon, "VLAN %d (%s):\n",
s->nc.vlan ? s->nc.vlan->id : -1,
s->nc.name);
slirp_connection_info(s->slirp, mon);
}
}
static int net_init_slirp_configs(const char *name, const char *value, void *opaque)
{
struct slirp_config_str *config;
if (strcmp(name, "hostfwd") != 0 && strcmp(name, "guestfwd") != 0) {
return 0;
}
config = g_malloc0(sizeof(*config));
pstrcpy(config->str, sizeof(config->str), value);
if (!strcmp(name, "hostfwd")) {
config->flags = SLIRP_CFG_HOSTFWD;
}
config->next = slirp_configs;
slirp_configs = config;
return 0;
}
int net_init_slirp(QemuOpts *opts,
Monitor *mon,
const char *name,
VLANState *vlan)
{
struct slirp_config_str *config;
const char *vhost;
const char *vhostname;
const char *vdhcp_start;
const char *vnamesrv;
const char *tftp_export;
const char *bootfile;
const char *smb_export;
const char *vsmbsrv;
const char *restrict_opt;
char *vnet = NULL;
int restricted = 0;
int ret;
vhost = qemu_opt_get(opts, "host");
vhostname = qemu_opt_get(opts, "hostname");
vdhcp_start = qemu_opt_get(opts, "dhcpstart");
vnamesrv = qemu_opt_get(opts, "dns");
tftp_export = qemu_opt_get(opts, "tftp");
bootfile = qemu_opt_get(opts, "bootfile");
smb_export = qemu_opt_get(opts, "smb");
vsmbsrv = qemu_opt_get(opts, "smbserver");
restrict_opt = qemu_opt_get(opts, "restrict");
if (restrict_opt) {
if (!strcmp(restrict_opt, "on") ||
!strcmp(restrict_opt, "yes") || !strcmp(restrict_opt, "y")) {
restricted = 1;
} else if (strcmp(restrict_opt, "off") &&
strcmp(restrict_opt, "no") && strcmp(restrict_opt, "n")) {
error_report("invalid option: 'restrict=%s'", restrict_opt);
return -1;
}
}
if (qemu_opt_get(opts, "ip")) {
const char *ip = qemu_opt_get(opts, "ip");
int l = strlen(ip) + strlen("/24") + 1;
vnet = g_malloc(l);
/* emulate legacy ip= parameter */
pstrcpy(vnet, l, ip);
pstrcat(vnet, l, "/24");
}
if (qemu_opt_get(opts, "net")) {
if (vnet) {
g_free(vnet);
}
vnet = g_strdup(qemu_opt_get(opts, "net"));
}
qemu_opt_foreach(opts, net_init_slirp_configs, NULL, 0);
ret = net_slirp_init(vlan, "user", name, restricted, vnet, vhost,
vhostname, tftp_export, bootfile, vdhcp_start,
vnamesrv, smb_export, vsmbsrv);
while (slirp_configs) {
config = slirp_configs;
slirp_configs = config->next;
g_free(config);
}
g_free(vnet);
return ret;
}
int net_slirp_parse_legacy(QemuOptsList *opts_list, const char *optarg, int *ret)
{
if (strcmp(opts_list->name, "net") != 0 ||
strncmp(optarg, "channel,", strlen("channel,")) != 0) {
return 0;
}
/* handle legacy -net channel,port:chr */
optarg += strlen("channel,");
if (QTAILQ_EMPTY(&slirp_stacks)) {
struct slirp_config_str *config;
config = g_malloc(sizeof(*config));
pstrcpy(config->str, sizeof(config->str), optarg);
config->flags = SLIRP_CFG_LEGACY;
config->next = slirp_configs;
slirp_configs = config;
*ret = 0;
} else {
*ret = slirp_guestfwd(QTAILQ_FIRST(&slirp_stacks), optarg, 1);
}
return 1;
}
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