xref: /qemu/net/slirp.c (revision 1b3e6f88dc151578acb6158e22570cf3ee7cbb69) 
1 /*
2  * QEMU System Emulator
3  *
4  * Copyright (c) 2003-2008 Fabrice Bellard
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 #include "net/slirp.h"
25 
26 #include "config-host.h"
27 
28 #ifndef _WIN32
29 #include <pwd.h>
30 #include <sys/wait.h>
31 #endif
32 #include "net.h"
33 #include "clients.h"
34 #include "hub.h"
35 #include "monitor.h"
36 #include "qemu_socket.h"
37 #include "slirp/libslirp.h"
38 
39 static int get_str_sep(char *buf, int buf_size, const char **pp, int sep)
40 {
41     const char *p, *p1;
42     int len;
43     p = *pp;
44     p1 = strchr(p, sep);
45     if (!p1)
46         return -1;
47     len = p1 - p;
48     p1++;
49     if (buf_size > 0) {
50         if (len > buf_size - 1)
51             len = buf_size - 1;
52         memcpy(buf, p, len);
53         buf[len] = '\0';
54     }
55     *pp = p1;
56     return 0;
57 }
58 
59 /* slirp network adapter */
60 
61 #define SLIRP_CFG_HOSTFWD 1
62 #define SLIRP_CFG_LEGACY  2
63 
64 struct slirp_config_str {
65     struct slirp_config_str *next;
66     int flags;
67     char str[1024];
68     int legacy_format;
69 };
70 
71 typedef struct SlirpState {
72     NetClientState nc;
73     QTAILQ_ENTRY(SlirpState) entry;
74     Slirp *slirp;
75 #ifndef _WIN32
76     char smb_dir[128];
77 #endif
78 } SlirpState;
79 
80 static struct slirp_config_str *slirp_configs;
81 const char *legacy_tftp_prefix;
82 const char *legacy_bootp_filename;
83 static QTAILQ_HEAD(slirp_stacks, SlirpState) slirp_stacks =
84     QTAILQ_HEAD_INITIALIZER(slirp_stacks);
85 
86 static int slirp_hostfwd(SlirpState *s, const char *redir_str,
87                          int legacy_format);
88 static int slirp_guestfwd(SlirpState *s, const char *config_str,
89                           int legacy_format);
90 
91 #ifndef _WIN32
92 static const char *legacy_smb_export;
93 
94 static int slirp_smb(SlirpState *s, const char *exported_dir,
95                      struct in_addr vserver_addr);
96 static void slirp_smb_cleanup(SlirpState *s);
97 #else
98 static inline void slirp_smb_cleanup(SlirpState *s) { }
99 #endif
100 
101 void slirp_output(void *opaque, const uint8_t *pkt, int pkt_len)
102 {
103     SlirpState *s = opaque;
104 
105     qemu_send_packet(&s->nc, pkt, pkt_len);
106 }
107 
108 static ssize_t net_slirp_receive(NetClientState *nc, const uint8_t *buf, size_t size)
109 {
110     SlirpState *s = DO_UPCAST(SlirpState, nc, nc);
111 
112     slirp_input(s->slirp, buf, size);
113 
114     return size;
115 }
116 
117 static void net_slirp_cleanup(NetClientState *nc)
118 {
119     SlirpState *s = DO_UPCAST(SlirpState, nc, nc);
120 
121     slirp_cleanup(s->slirp);
122     slirp_smb_cleanup(s);
123     QTAILQ_REMOVE(&slirp_stacks, s, entry);
124 }
125 
126 static NetClientInfo net_slirp_info = {
127     .type = NET_CLIENT_OPTIONS_KIND_USER,
128     .size = sizeof(SlirpState),
129     .receive = net_slirp_receive,
130     .cleanup = net_slirp_cleanup,
131 };
132 
133 static int net_slirp_init(NetClientState *peer, const char *model,
134                           const char *name, int restricted,
135                           const char *vnetwork, const char *vhost,
136                           const char *vhostname, const char *tftp_export,
137                           const char *bootfile, const char *vdhcp_start,
138                           const char *vnameserver, const char *smb_export,
139                           const char *vsmbserver)
140 {
141     /* default settings according to historic slirp */
142     struct in_addr net  = { .s_addr = htonl(0x0a000200) }; /* 10.0.2.0 */
143     struct in_addr mask = { .s_addr = htonl(0xffffff00) }; /* 255.255.255.0 */
144     struct in_addr host = { .s_addr = htonl(0x0a000202) }; /* 10.0.2.2 */
145     struct in_addr dhcp = { .s_addr = htonl(0x0a00020f) }; /* 10.0.2.15 */
146     struct in_addr dns  = { .s_addr = htonl(0x0a000203) }; /* 10.0.2.3 */
147 #ifndef _WIN32
148     struct in_addr smbsrv = { .s_addr = 0 };
149 #endif
150     NetClientState *nc;
151     SlirpState *s;
152     char buf[20];
153     uint32_t addr;
154     int shift;
155     char *end;
156     struct slirp_config_str *config;
157 
158     if (!tftp_export) {
159         tftp_export = legacy_tftp_prefix;
160     }
161     if (!bootfile) {
162         bootfile = legacy_bootp_filename;
163     }
164 
165     if (vnetwork) {
166         if (get_str_sep(buf, sizeof(buf), &vnetwork, '/') < 0) {
167             if (!inet_aton(vnetwork, &net)) {
168                 return -1;
169             }
170             addr = ntohl(net.s_addr);
171             if (!(addr & 0x80000000)) {
172                 mask.s_addr = htonl(0xff000000); /* class A */
173             } else if ((addr & 0xfff00000) == 0xac100000) {
174                 mask.s_addr = htonl(0xfff00000); /* priv. 172.16.0.0/12 */
175             } else if ((addr & 0xc0000000) == 0x80000000) {
176                 mask.s_addr = htonl(0xffff0000); /* class B */
177             } else if ((addr & 0xffff0000) == 0xc0a80000) {
178                 mask.s_addr = htonl(0xffff0000); /* priv. 192.168.0.0/16 */
179             } else if ((addr & 0xffff0000) == 0xc6120000) {
180                 mask.s_addr = htonl(0xfffe0000); /* tests 198.18.0.0/15 */
181             } else if ((addr & 0xe0000000) == 0xe0000000) {
182                 mask.s_addr = htonl(0xffffff00); /* class C */
183             } else {
184                 mask.s_addr = htonl(0xfffffff0); /* multicast/reserved */
185             }
186         } else {
187             if (!inet_aton(buf, &net)) {
188                 return -1;
189             }
190             shift = strtol(vnetwork, &end, 10);
191             if (*end != '\0') {
192                 if (!inet_aton(vnetwork, &mask)) {
193                     return -1;
194                 }
195             } else if (shift < 4 || shift > 32) {
196                 return -1;
197             } else {
198                 mask.s_addr = htonl(0xffffffff << (32 - shift));
199             }
200         }
201         net.s_addr &= mask.s_addr;
202         host.s_addr = net.s_addr | (htonl(0x0202) & ~mask.s_addr);
203         dhcp.s_addr = net.s_addr | (htonl(0x020f) & ~mask.s_addr);
204         dns.s_addr  = net.s_addr | (htonl(0x0203) & ~mask.s_addr);
205     }
206 
207     if (vhost && !inet_aton(vhost, &host)) {
208         return -1;
209     }
210     if ((host.s_addr & mask.s_addr) != net.s_addr) {
211         return -1;
212     }
213 
214     if (vdhcp_start && !inet_aton(vdhcp_start, &dhcp)) {
215         return -1;
216     }
217     if ((dhcp.s_addr & mask.s_addr) != net.s_addr ||
218         dhcp.s_addr == host.s_addr || dhcp.s_addr == dns.s_addr) {
219         return -1;
220     }
221 
222     if (vnameserver && !inet_aton(vnameserver, &dns)) {
223         return -1;
224     }
225     if ((dns.s_addr & mask.s_addr) != net.s_addr ||
226         dns.s_addr == host.s_addr) {
227         return -1;
228     }
229 
230 #ifndef _WIN32
231     if (vsmbserver && !inet_aton(vsmbserver, &smbsrv)) {
232         return -1;
233     }
234 #endif
235 
236     nc = qemu_new_net_client(&net_slirp_info, peer, model, name);
237 
238     snprintf(nc->info_str, sizeof(nc->info_str),
239              "net=%s,restrict=%s", inet_ntoa(net),
240              restricted ? "on" : "off");
241 
242     s = DO_UPCAST(SlirpState, nc, nc);
243 
244     s->slirp = slirp_init(restricted, net, mask, host, vhostname,
245                           tftp_export, bootfile, dhcp, dns, s);
246     QTAILQ_INSERT_TAIL(&slirp_stacks, s, entry);
247 
248     for (config = slirp_configs; config; config = config->next) {
249         if (config->flags & SLIRP_CFG_HOSTFWD) {
250             if (slirp_hostfwd(s, config->str,
251                               config->flags & SLIRP_CFG_LEGACY) < 0)
252                 goto error;
253         } else {
254             if (slirp_guestfwd(s, config->str,
255                                config->flags & SLIRP_CFG_LEGACY) < 0)
256                 goto error;
257         }
258     }
259 #ifndef _WIN32
260     if (!smb_export) {
261         smb_export = legacy_smb_export;
262     }
263     if (smb_export) {
264         if (slirp_smb(s, smb_export, smbsrv) < 0)
265             goto error;
266     }
267 #endif
268 
269     return 0;
270 
271 error:
272     qemu_del_net_client(nc);
273     return -1;
274 }
275 
276 static SlirpState *slirp_lookup(Monitor *mon, const char *vlan,
277                                 const char *stack)
278 {
279 
280     if (vlan) {
281         NetClientState *nc;
282         nc = net_hub_find_client_by_name(strtol(vlan, NULL, 0), stack);
283         if (!nc) {
284             return NULL;
285         }
286         if (strcmp(nc->model, "user")) {
287             monitor_printf(mon, "invalid device specified\n");
288             return NULL;
289         }
290         return DO_UPCAST(SlirpState, nc, nc);
291     } else {
292         if (QTAILQ_EMPTY(&slirp_stacks)) {
293             monitor_printf(mon, "user mode network stack not in use\n");
294             return NULL;
295         }
296         return QTAILQ_FIRST(&slirp_stacks);
297     }
298 }
299 
300 void net_slirp_hostfwd_remove(Monitor *mon, const QDict *qdict)
301 {
302     struct in_addr host_addr = { .s_addr = INADDR_ANY };
303     int host_port;
304     char buf[256];
305     const char *src_str, *p;
306     SlirpState *s;
307     int is_udp = 0;
308     int err;
309     const char *arg1 = qdict_get_str(qdict, "arg1");
310     const char *arg2 = qdict_get_try_str(qdict, "arg2");
311     const char *arg3 = qdict_get_try_str(qdict, "arg3");
312 
313     if (arg2) {
314         s = slirp_lookup(mon, arg1, arg2);
315         src_str = arg3;
316     } else {
317         s = slirp_lookup(mon, NULL, NULL);
318         src_str = arg1;
319     }
320     if (!s) {
321         return;
322     }
323 
324     p = src_str;
325     if (!p || get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
326         goto fail_syntax;
327     }
328 
329     if (!strcmp(buf, "tcp") || buf[0] == '\0') {
330         is_udp = 0;
331     } else if (!strcmp(buf, "udp")) {
332         is_udp = 1;
333     } else {
334         goto fail_syntax;
335     }
336 
337     if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
338         goto fail_syntax;
339     }
340     if (buf[0] != '\0' && !inet_aton(buf, &host_addr)) {
341         goto fail_syntax;
342     }
343 
344     host_port = atoi(p);
345 
346     err = slirp_remove_hostfwd(QTAILQ_FIRST(&slirp_stacks)->slirp, is_udp,
347                                host_addr, host_port);
348 
349     monitor_printf(mon, "host forwarding rule for %s %s\n", src_str,
350                    err ? "not found" : "removed");
351     return;
352 
353  fail_syntax:
354     monitor_printf(mon, "invalid format\n");
355 }
356 
357 static int slirp_hostfwd(SlirpState *s, const char *redir_str,
358                          int legacy_format)
359 {
360     struct in_addr host_addr = { .s_addr = INADDR_ANY };
361     struct in_addr guest_addr = { .s_addr = 0 };
362     int host_port, guest_port;
363     const char *p;
364     char buf[256];
365     int is_udp;
366     char *end;
367 
368     p = redir_str;
369     if (!p || get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
370         goto fail_syntax;
371     }
372     if (!strcmp(buf, "tcp") || buf[0] == '\0') {
373         is_udp = 0;
374     } else if (!strcmp(buf, "udp")) {
375         is_udp = 1;
376     } else {
377         goto fail_syntax;
378     }
379 
380     if (!legacy_format) {
381         if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
382             goto fail_syntax;
383         }
384         if (buf[0] != '\0' && !inet_aton(buf, &host_addr)) {
385             goto fail_syntax;
386         }
387     }
388 
389     if (get_str_sep(buf, sizeof(buf), &p, legacy_format ? ':' : '-') < 0) {
390         goto fail_syntax;
391     }
392     host_port = strtol(buf, &end, 0);
393     if (*end != '\0' || host_port < 1 || host_port > 65535) {
394         goto fail_syntax;
395     }
396 
397     if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
398         goto fail_syntax;
399     }
400     if (buf[0] != '\0' && !inet_aton(buf, &guest_addr)) {
401         goto fail_syntax;
402     }
403 
404     guest_port = strtol(p, &end, 0);
405     if (*end != '\0' || guest_port < 1 || guest_port > 65535) {
406         goto fail_syntax;
407     }
408 
409     if (slirp_add_hostfwd(s->slirp, is_udp, host_addr, host_port, guest_addr,
410                           guest_port) < 0) {
411         error_report("could not set up host forwarding rule '%s'",
412                      redir_str);
413         return -1;
414     }
415     return 0;
416 
417  fail_syntax:
418     error_report("invalid host forwarding rule '%s'", redir_str);
419     return -1;
420 }
421 
422 void net_slirp_hostfwd_add(Monitor *mon, const QDict *qdict)
423 {
424     const char *redir_str;
425     SlirpState *s;
426     const char *arg1 = qdict_get_str(qdict, "arg1");
427     const char *arg2 = qdict_get_try_str(qdict, "arg2");
428     const char *arg3 = qdict_get_try_str(qdict, "arg3");
429 
430     if (arg2) {
431         s = slirp_lookup(mon, arg1, arg2);
432         redir_str = arg3;
433     } else {
434         s = slirp_lookup(mon, NULL, NULL);
435         redir_str = arg1;
436     }
437     if (s) {
438         slirp_hostfwd(s, redir_str, 0);
439     }
440 
441 }
442 
443 int net_slirp_redir(const char *redir_str)
444 {
445     struct slirp_config_str *config;
446 
447     if (QTAILQ_EMPTY(&slirp_stacks)) {
448         config = g_malloc(sizeof(*config));
449         pstrcpy(config->str, sizeof(config->str), redir_str);
450         config->flags = SLIRP_CFG_HOSTFWD | SLIRP_CFG_LEGACY;
451         config->next = slirp_configs;
452         slirp_configs = config;
453         return 0;
454     }
455 
456     return slirp_hostfwd(QTAILQ_FIRST(&slirp_stacks), redir_str, 1);
457 }
458 
459 #ifndef _WIN32
460 
461 /* automatic user mode samba server configuration */
462 static void slirp_smb_cleanup(SlirpState *s)
463 {
464     char cmd[128];
465     int ret;
466 
467     if (s->smb_dir[0] != '\0') {
468         snprintf(cmd, sizeof(cmd), "rm -rf %s", s->smb_dir);
469         ret = system(cmd);
470         if (ret == -1 || !WIFEXITED(ret)) {
471             error_report("'%s' failed.", cmd);
472         } else if (WEXITSTATUS(ret)) {
473             error_report("'%s' failed. Error code: %d",
474                          cmd, WEXITSTATUS(ret));
475         }
476         s->smb_dir[0] = '\0';
477     }
478 }
479 
480 static int slirp_smb(SlirpState* s, const char *exported_dir,
481                      struct in_addr vserver_addr)
482 {
483     static int instance;
484     char smb_conf[128];
485     char smb_cmdline[128];
486     struct passwd *passwd;
487     FILE *f;
488 
489     passwd = getpwuid(geteuid());
490     if (!passwd) {
491         error_report("failed to retrieve user name");
492         return -1;
493     }
494 
495     if (access(CONFIG_SMBD_COMMAND, F_OK)) {
496         error_report("could not find '%s', please install it",
497                      CONFIG_SMBD_COMMAND);
498         return -1;
499     }
500 
501     if (access(exported_dir, R_OK | X_OK)) {
502         error_report("error accessing shared directory '%s': %s",
503                      exported_dir, strerror(errno));
504         return -1;
505     }
506 
507     snprintf(s->smb_dir, sizeof(s->smb_dir), "/tmp/qemu-smb.%ld-%d",
508              (long)getpid(), instance++);
509     if (mkdir(s->smb_dir, 0700) < 0) {
510         error_report("could not create samba server dir '%s'", s->smb_dir);
511         return -1;
512     }
513     snprintf(smb_conf, sizeof(smb_conf), "%s/%s", s->smb_dir, "smb.conf");
514 
515     f = fopen(smb_conf, "w");
516     if (!f) {
517         slirp_smb_cleanup(s);
518         error_report("could not create samba server configuration file '%s'",
519                      smb_conf);
520         return -1;
521     }
522     fprintf(f,
523             "[global]\n"
524             "private dir=%s\n"
525             "socket address=127.0.0.1\n"
526             "pid directory=%s\n"
527             "lock directory=%s\n"
528             "state directory=%s\n"
529             "log file=%s/log.smbd\n"
530             "smb passwd file=%s/smbpasswd\n"
531             "security = share\n"
532             "[qemu]\n"
533             "path=%s\n"
534             "read only=no\n"
535             "guest ok=yes\n"
536             "force user=%s\n",
537             s->smb_dir,
538             s->smb_dir,
539             s->smb_dir,
540             s->smb_dir,
541             s->smb_dir,
542             s->smb_dir,
543             exported_dir,
544             passwd->pw_name
545             );
546     fclose(f);
547 
548     snprintf(smb_cmdline, sizeof(smb_cmdline), "%s -s %s",
549              CONFIG_SMBD_COMMAND, smb_conf);
550 
551     if (slirp_add_exec(s->slirp, 0, smb_cmdline, &vserver_addr, 139) < 0) {
552         slirp_smb_cleanup(s);
553         error_report("conflicting/invalid smbserver address");
554         return -1;
555     }
556     return 0;
557 }
558 
559 /* automatic user mode samba server configuration (legacy interface) */
560 int net_slirp_smb(const char *exported_dir)
561 {
562     struct in_addr vserver_addr = { .s_addr = 0 };
563 
564     if (legacy_smb_export) {
565         fprintf(stderr, "-smb given twice\n");
566         return -1;
567     }
568     legacy_smb_export = exported_dir;
569     if (!QTAILQ_EMPTY(&slirp_stacks)) {
570         return slirp_smb(QTAILQ_FIRST(&slirp_stacks), exported_dir,
571                          vserver_addr);
572     }
573     return 0;
574 }
575 
576 #endif /* !defined(_WIN32) */
577 
578 struct GuestFwd {
579     CharDriverState *hd;
580     struct in_addr server;
581     int port;
582     Slirp *slirp;
583 };
584 
585 static int guestfwd_can_read(void *opaque)
586 {
587     struct GuestFwd *fwd = opaque;
588     return slirp_socket_can_recv(fwd->slirp, fwd->server, fwd->port);
589 }
590 
591 static void guestfwd_read(void *opaque, const uint8_t *buf, int size)
592 {
593     struct GuestFwd *fwd = opaque;
594     slirp_socket_recv(fwd->slirp, fwd->server, fwd->port, buf, size);
595 }
596 
597 static int slirp_guestfwd(SlirpState *s, const char *config_str,
598                           int legacy_format)
599 {
600     struct in_addr server = { .s_addr = 0 };
601     struct GuestFwd *fwd;
602     const char *p;
603     char buf[128];
604     char *end;
605     int port;
606 
607     p = config_str;
608     if (legacy_format) {
609         if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
610             goto fail_syntax;
611         }
612     } else {
613         if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
614             goto fail_syntax;
615         }
616         if (strcmp(buf, "tcp") && buf[0] != '\0') {
617             goto fail_syntax;
618         }
619         if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
620             goto fail_syntax;
621         }
622         if (buf[0] != '\0' && !inet_aton(buf, &server)) {
623             goto fail_syntax;
624         }
625         if (get_str_sep(buf, sizeof(buf), &p, '-') < 0) {
626             goto fail_syntax;
627         }
628     }
629     port = strtol(buf, &end, 10);
630     if (*end != '\0' || port < 1 || port > 65535) {
631         goto fail_syntax;
632     }
633 
634     fwd = g_malloc(sizeof(struct GuestFwd));
635     snprintf(buf, sizeof(buf), "guestfwd.tcp.%d", port);
636 
637     if ((strlen(p) > 4) && !strncmp(p, "cmd:", 4)) {
638         if (slirp_add_exec(s->slirp, 0, &p[4], &server, port) < 0) {
639             error_report("conflicting/invalid host:port in guest forwarding "
640                          "rule '%s'", config_str);
641             g_free(fwd);
642             return -1;
643         }
644     } else {
645         fwd->hd = qemu_chr_new(buf, p, NULL);
646         if (!fwd->hd) {
647             error_report("could not open guest forwarding device '%s'", buf);
648             g_free(fwd);
649             return -1;
650         }
651 
652         if (slirp_add_exec(s->slirp, 3, fwd->hd, &server, port) < 0) {
653             error_report("conflicting/invalid host:port in guest forwarding "
654                          "rule '%s'", config_str);
655             g_free(fwd);
656             return -1;
657         }
658         fwd->server = server;
659         fwd->port = port;
660         fwd->slirp = s->slirp;
661 
662         qemu_chr_add_handlers(fwd->hd, guestfwd_can_read, guestfwd_read,
663                               NULL, fwd);
664     }
665     return 0;
666 
667  fail_syntax:
668     error_report("invalid guest forwarding rule '%s'", config_str);
669     return -1;
670 }
671 
672 void do_info_usernet(Monitor *mon)
673 {
674     SlirpState *s;
675 
676     QTAILQ_FOREACH(s, &slirp_stacks, entry) {
677         int id;
678         bool got_vlan_id = net_hub_id_for_client(&s->nc, &id) == 0;
679         monitor_printf(mon, "VLAN %d (%s):\n",
680                        got_vlan_id ? id : -1,
681                        s->nc.name);
682         slirp_connection_info(s->slirp, mon);
683     }
684 }
685 
686 static void
687 net_init_slirp_configs(const StringList *fwd, int flags)
688 {
689     while (fwd) {
690         struct slirp_config_str *config;
691 
692         config = g_malloc0(sizeof(*config));
693         pstrcpy(config->str, sizeof(config->str), fwd->value->str);
694         config->flags = flags;
695         config->next = slirp_configs;
696         slirp_configs = config;
697 
698         fwd = fwd->next;
699     }
700 }
701 
702 int net_init_slirp(const NetClientOptions *opts, const char *name,
703                    NetClientState *peer)
704 {
705     struct slirp_config_str *config;
706     char *vnet;
707     int ret;
708     const NetdevUserOptions *user;
709 
710     assert(opts->kind == NET_CLIENT_OPTIONS_KIND_USER);
711     user = opts->user;
712 
713     vnet = user->has_net ? g_strdup(user->net) :
714            user->has_ip  ? g_strdup_printf("%s/24", user->ip) :
715            NULL;
716 
717     /* all optional fields are initialized to "all bits zero" */
718 
719     net_init_slirp_configs(user->hostfwd, SLIRP_CFG_HOSTFWD);
720     net_init_slirp_configs(user->guestfwd, 0);
721 
722     ret = net_slirp_init(peer, "user", name, user->q_restrict, vnet,
723                          user->host, user->hostname, user->tftp,
724                          user->bootfile, user->dhcpstart, user->dns, user->smb,
725                          user->smbserver);
726 
727     while (slirp_configs) {
728         config = slirp_configs;
729         slirp_configs = config->next;
730         g_free(config);
731     }
732 
733     g_free(vnet);
734 
735     return ret;
736 }
737 
738 int net_slirp_parse_legacy(QemuOptsList *opts_list, const char *optarg, int *ret)
739 {
740     if (strcmp(opts_list->name, "net") != 0 ||
741         strncmp(optarg, "channel,", strlen("channel,")) != 0) {
742         return 0;
743     }
744 
745     /* handle legacy -net channel,port:chr */
746     optarg += strlen("channel,");
747 
748     if (QTAILQ_EMPTY(&slirp_stacks)) {
749         struct slirp_config_str *config;
750 
751         config = g_malloc(sizeof(*config));
752         pstrcpy(config->str, sizeof(config->str), optarg);
753         config->flags = SLIRP_CFG_LEGACY;
754         config->next = slirp_configs;
755         slirp_configs = config;
756         *ret = 0;
757     } else {
758         *ret = slirp_guestfwd(QTAILQ_FIRST(&slirp_stacks), optarg, 1);
759     }
760 
761     return 1;
762 }
763 
764