slirp/src/misc.c

   1 /* SPDX-License-Identifier: BSD-3-Clause */
   2 /*
   3  * Copyright (c) 1995 Danny Gasparovski.
   4  */
   5
   6 #include "slirp.h"
   7
   8 inline void
   9 insque(void *a, void *b)
  10 {
  11         register struct quehead *element = (struct quehead *) a;
  12         register struct quehead *head = (struct quehead *) b;
  13         element->qh_link = head->qh_link;
  14         head->qh_link = (struct quehead *)element;
  15         element->qh_rlink = (struct quehead *)head;
  16         ((struct quehead *)(element->qh_link))->qh_rlink
  17         = (struct quehead *)element;
  18 }
  19
  20 inline void
  21 remque(void *a)
  22 {
  23   register struct quehead *element = (struct quehead *) a;
  24   ((struct quehead *)(element->qh_link))->qh_rlink = element->qh_rlink;
  25   ((struct quehead *)(element->qh_rlink))->qh_link = element->qh_link;
  26   element->qh_rlink = NULL;
  27 }
  28
  29 /* TODO: IPv6 */
  30 struct gfwd_list *
  31 add_guestfwd(struct gfwd_list **ex_ptr,
  32              SlirpWriteCb write_cb, void *opaque,
  33              struct in_addr addr, int port)
  34 {
  35     struct gfwd_list *f = g_new0(struct gfwd_list, 1);
  36
  37     f->write_cb = write_cb;
  38     f->opaque = opaque;
  39     f->ex_fport = port;
  40     f->ex_addr = addr;
  41     f->ex_next = *ex_ptr;
  42     *ex_ptr = f;
  43
  44     return f;
  45 }
  46
  47 struct gfwd_list *
  48 add_exec(struct gfwd_list **ex_ptr, const char *cmdline,
  49          struct in_addr addr, int port)
  50 {
  51     struct gfwd_list *f = add_guestfwd(ex_ptr, NULL, NULL, addr, port);
  52
  53     f->ex_exec = g_strdup(cmdline);
  54
  55     return f;
  56 }
  57
  58 static int
  59 slirp_socketpair_with_oob(int sv[2])
  60 {
  61     struct sockaddr_in addr = {
  62         .sin_family = AF_INET,
  63         .sin_port = 0,
  64         .sin_addr.s_addr = INADDR_ANY,
  65     };
  66     socklen_t addrlen = sizeof(addr);
  67     int ret, s;
  68
  69     sv[1] = -1;
  70     s = slirp_socket(AF_INET, SOCK_STREAM, 0);
  71     if (s < 0 || bind(s, (struct sockaddr *)&addr, addrlen) < 0 ||
  72         listen(s, 1) < 0 ||
  73         getsockname(s, (struct sockaddr *)&addr, &addrlen) < 0) {
  74         goto err;
  75     }
  76
  77     sv[1] = slirp_socket(AF_INET, SOCK_STREAM, 0);
  78     if (sv[1] < 0) {
  79         goto err;
  80     }
  81     /*
  82      * This connect won't block because we've already listen()ed on
  83      * the server end (even though we won't accept() the connection
  84      * until later on).
  85      */
  86     do {
  87         ret = connect(sv[1], (struct sockaddr *)&addr, addrlen);
  88     } while (ret < 0 && errno == EINTR);
  89     if (ret < 0) {
  90         goto err;
  91     }
  92
  93     do {
  94         sv[0] = accept(s, (struct sockaddr *)&addr, &addrlen);
  95     } while (sv[0] < 0 && errno == EINTR);
  96     if (sv[0] < 0) {
  97         goto err;
  98     }
  99
 100     closesocket(s);
 101     return 0;
 102
 103 err:
 104     g_critical("slirp_socketpair(): %s", strerror(errno));
 105     if (s >= 0) {
 106         closesocket(s);
 107     }
 108     if (sv[1] >= 0) {
 109         closesocket(sv[1]);
 110     }
 111     return -1;
 112 }
 113
 114 static void
 115 fork_exec_child_setup(gpointer data)
 116 {
 117 #ifndef _WIN32
 118     setsid();
 119 #endif
 120 }
 121
 122 #pragma GCC diagnostic push
 123 #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
 124
 125 #if !GLIB_CHECK_VERSION(2, 58, 0)
 126 typedef struct SlirpGSpawnFds {
 127     GSpawnChildSetupFunc child_setup;
 128     gpointer user_data;
 129     gint stdin_fd;
 130     gint stdout_fd;
 131     gint stderr_fd;
 132 } SlirpGSpawnFds;
 133
 134 static inline void
 135 slirp_gspawn_fds_setup(gpointer user_data)
 136 {
 137     SlirpGSpawnFds *q = (SlirpGSpawnFds *)user_data;
 138
 139     dup2(q->stdin_fd, 0);
 140     dup2(q->stdout_fd, 1);
 141     dup2(q->stderr_fd, 2);
 142     q->child_setup(q->user_data);
 143 }
 144 #endif
 145
 146 static inline gboolean
 147 g_spawn_async_with_fds_slirp(const gchar *working_directory,
 148                             gchar **argv,
 149                             gchar **envp,
 150                             GSpawnFlags flags,
 151                             GSpawnChildSetupFunc child_setup,
 152                             gpointer user_data,
 153                             GPid *child_pid,
 154                             gint stdin_fd,
 155                             gint stdout_fd,
 156                             gint stderr_fd,
 157                             GError **error)
 158 {
 159 #if GLIB_CHECK_VERSION(2, 58, 0)
 160     return g_spawn_async_with_fds(working_directory, argv, envp, flags,
 161                                   child_setup, user_data,
 162                                   child_pid, stdin_fd, stdout_fd, stderr_fd,
 163                                   error);
 164 #else
 165     SlirpGSpawnFds setup = {
 166         .child_setup = child_setup,
 167         .user_data = user_data,
 168         .stdin_fd = stdin_fd,
 169         .stdout_fd = stdout_fd,
 170         .stderr_fd = stderr_fd,
 171     };
 172
 173     return g_spawn_async(working_directory, argv, envp, flags,
 174                          slirp_gspawn_fds_setup, &setup,
 175                          child_pid, error);
 176 #endif
 177 }
 178
 179 #define g_spawn_async_with_fds(wd, argv, env, f, c, d, p, ifd, ofd, efd, err) \
 180     g_spawn_async_with_fds_slirp(wd, argv, env, f, c, d, p, ifd, ofd, efd, err)
 181
 182 #pragma GCC diagnostic pop
 183
 184 int
 185 fork_exec(struct socket *so, const char *ex)
 186 {
 187     GError *err = NULL;
 188     char **argv;
 189     int opt, sp[2];
 190
 191     DEBUG_CALL("fork_exec");
 192     DEBUG_ARG("so = %p", so);
 193     DEBUG_ARG("ex = %p", ex);
 194
 195     if (slirp_socketpair_with_oob(sp) < 0) {
 196         return 0;
 197     }
 198
 199     argv = g_strsplit(ex, " ", -1);
 200     g_spawn_async_with_fds(NULL /* cwd */,
 201                            argv,
 202                            NULL /* env */,
 203                            G_SPAWN_SEARCH_PATH,
 204                            fork_exec_child_setup, NULL /* data */,
 205                            NULL /* child_pid */,
 206                            sp[1], sp[1], sp[1],
 207                            &err);
 208     g_strfreev(argv);
 209
 210     if (err) {
 211         g_critical("fork_exec: %s", err->message);
 212         g_error_free(err);
 213         closesocket(sp[0]);
 214         closesocket(sp[1]);
 215         return 0;
 216     }
 217
 218     so->s = sp[0];
 219     closesocket(sp[1]);
 220     slirp_socket_set_fast_reuse(so->s);
 221     opt = 1;
 222     setsockopt(so->s, SOL_SOCKET, SO_OOBINLINE, &opt, sizeof(int));
 223     slirp_set_nonblock(so->s);
 224     so->slirp->cb->register_poll_fd(so->s, so->slirp->opaque);
 225     return 1;
 226 }
 227
 228 char *slirp_connection_info(Slirp *slirp)
 229 {
 230     GString *str = g_string_new(NULL);
 231     const char * const tcpstates[] = {
 232         [TCPS_CLOSED]       = "CLOSED",
 233         [TCPS_LISTEN]       = "LISTEN",
 234         [TCPS_SYN_SENT]     = "SYN_SENT",
 235         [TCPS_SYN_RECEIVED] = "SYN_RCVD",
 236         [TCPS_ESTABLISHED]  = "ESTABLISHED",
 237         [TCPS_CLOSE_WAIT]   = "CLOSE_WAIT",
 238         [TCPS_FIN_WAIT_1]   = "FIN_WAIT_1",
 239         [TCPS_CLOSING]      = "CLOSING",
 240         [TCPS_LAST_ACK]     = "LAST_ACK",
 241         [TCPS_FIN_WAIT_2]   = "FIN_WAIT_2",
 242         [TCPS_TIME_WAIT]    = "TIME_WAIT",
 243     };
 244     struct in_addr dst_addr;
 245     struct sockaddr_in src;
 246     socklen_t src_len;
 247     uint16_t dst_port;
 248     struct socket *so;
 249     const char *state;
 250     char buf[20];
 251
 252     g_string_append_printf(str,
 253         "  Protocol[State]    FD  Source Address  Port   "
 254         "Dest. Address  Port RecvQ SendQ\n");
 255
 256     /* TODO: IPv6 */
 257
 258     for (so = slirp->tcb.so_next; so != &slirp->tcb; so = so->so_next) {
 259         if (so->so_state & SS_HOSTFWD) {
 260             state = "HOST_FORWARD";
 261         } else if (so->so_tcpcb) {
 262             state = tcpstates[so->so_tcpcb->t_state];
 263         } else {
 264             state = "NONE";
 265         }
 266         if (so->so_state & (SS_HOSTFWD | SS_INCOMING)) {
 267             src_len = sizeof(src);
 268             getsockname(so->s, (struct sockaddr *)&src, &src_len);
 269             dst_addr = so->so_laddr;
 270             dst_port = so->so_lport;
 271         } else {
 272             src.sin_addr = so->so_laddr;
 273             src.sin_port = so->so_lport;
 274             dst_addr = so->so_faddr;
 275             dst_port = so->so_fport;
 276         }
 277         snprintf(buf, sizeof(buf), "  TCP[%s]", state);
 278         g_string_append_printf(str, "%-19s %3d %15s %5d ", buf, so->s,
 279                        src.sin_addr.s_addr ? inet_ntoa(src.sin_addr) : "*",
 280                        ntohs(src.sin_port));
 281         g_string_append_printf(str, "%15s %5d %5d %5d\n",
 282                        inet_ntoa(dst_addr), ntohs(dst_port),
 283                        so->so_rcv.sb_cc, so->so_snd.sb_cc);
 284     }
 285
 286     for (so = slirp->udb.so_next; so != &slirp->udb; so = so->so_next) {
 287         if (so->so_state & SS_HOSTFWD) {
 288             snprintf(buf, sizeof(buf), "  UDP[HOST_FORWARD]");
 289             src_len = sizeof(src);
 290             getsockname(so->s, (struct sockaddr *)&src, &src_len);
 291             dst_addr = so->so_laddr;
 292             dst_port = so->so_lport;
 293         } else {
 294             snprintf(buf, sizeof(buf), "  UDP[%d sec]",
 295                          (so->so_expire - curtime) / 1000);
 296             src.sin_addr = so->so_laddr;
 297             src.sin_port = so->so_lport;
 298             dst_addr = so->so_faddr;
 299             dst_port = so->so_fport;
 300         }
 301         g_string_append_printf(str, "%-19s %3d %15s %5d ", buf, so->s,
 302                        src.sin_addr.s_addr ? inet_ntoa(src.sin_addr) : "*",
 303                        ntohs(src.sin_port));
 304         g_string_append_printf(str, "%15s %5d %5d %5d\n",
 305                        inet_ntoa(dst_addr), ntohs(dst_port),
 306                        so->so_rcv.sb_cc, so->so_snd.sb_cc);
 307     }
 308
 309     for (so = slirp->icmp.so_next; so != &slirp->icmp; so = so->so_next) {
 310         snprintf(buf, sizeof(buf), "  ICMP[%d sec]",
 311                      (so->so_expire - curtime) / 1000);
 312         src.sin_addr = so->so_laddr;
 313         dst_addr = so->so_faddr;
 314         g_string_append_printf(str, "%-19s %3d %15s  -    ", buf, so->s,
 315                        src.sin_addr.s_addr ? inet_ntoa(src.sin_addr) : "*");
 316         g_string_append_printf(str, "%15s  -    %5d %5d\n", inet_ntoa(dst_addr),
 317                        so->so_rcv.sb_cc, so->so_snd.sb_cc);
 318     }
 319
 320     return g_string_free(str, FALSE);
 321 }