Redirect slirp traffic to/from qemu character device (Gleb Natapov)

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6240 c046a42c-6fe2-441c-8c8c-71466251a162

8 files changed, 153 insertions, 24 deletions

diff --git a/libslirp.h b/libslirp.h
index 792c9a8..24cc8b0 100644
--- a/libslirp.h
+++ b/libslirp.h
@@ -20,13 +20,16 @@ void slirp_output(const uint8_t *pkt, int pkt_len);
 
 int slirp_redir(int is_udp, int host_port, struct in_addr guest_addr,
                 int guest_port);
-int slirp_add_exec(int do_pty, const char *args, int addr_low_byte,
+int slirp_add_exec(int do_pty, const void *args, int addr_low_byte,
                    int guest_port);
 
 extern const char *tftp_prefix;
 extern char slirp_hostname[33];
 
 void slirp_stats(void);
+void slirp_socket_recv(int addr_low_byte, int guest_port, const uint8_t *buf,
+                       int size);
+size_t slirp_socket_can_recv(int addr_low_byte, int guest_port);
 
 #ifdef __cplusplus
 }
diff --git a/main.h b/main.h
index 7c87c10..b02c879 100644
--- a/main.h
+++ b/main.h
@@ -51,3 +51,4 @@ extern uint8_t client_ethaddr[6];
 #endif
 
 void if_encap(const uint8_t *ip_data, int ip_data_len);
+ssize_t slirp_send(struct socket *so, const void *buf, size_t len, int flags);
diff --git a/misc.c b/misc.c
index f516929..152f416 100644
--- a/misc.c
+++ b/misc.c
@@ -157,7 +157,7 @@ int port;
     (*ex_ptr)->ex_fport = port;
     (*ex_ptr)->ex_addr = addr;
     (*ex_ptr)->ex_pty = do_pty;
-    (*ex_ptr)->ex_exec = strdup(exec);
+    (*ex_ptr)->ex_exec = (do_pty == 3) ? exec : strdup(exec);
     (*ex_ptr)->ex_next = tmp_ptr;
     return 0;
 }
diff --git a/sbuf.c b/sbuf.c
index ac2fbd8..ab6d270 100644
--- a/sbuf.c
+++ b/sbuf.c
@@ -100,7 +100,7 @@ struct mbuf *m;
      * ottherwise it'll arrive out of order, and hence corrupt
      */
     if (!so->so_rcv.sb_cc)
-        ret = send(so->s, m->m_data, m->m_len, 0);
+        ret = slirp_send(so, m->m_data, m->m_len, 0);
 
     if (ret <= 0) {
         /*
diff --git a/slirp.c b/slirp.c
index 96a8c2d..490ab26 100644
--- a/slirp.c
+++ b/slirp.c
@@ -21,6 +21,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
+#include "qemu-common.h"
 #include "slirp.h"
 
 /* host address */
@@ -738,9 +739,67 @@ int slirp_redir(int is_udp, int host_port, struct in_addr guest_addr,
     return 0;
 }
 
-int slirp_add_exec(int do_pty, const char *args, int addr_low_byte,
+int slirp_add_exec(int do_pty, const void *args, int addr_low_byte,
                    int guest_port)
 {
     return add_exec(&exec_list, do_pty, (char *)args, addr_low_byte,
                     htons(guest_port));
 }
+
+ssize_t slirp_send(struct socket *so, const void *buf, size_t len, int flags)
+{
+    if (so->s == -1 && so->extra) {
+        qemu_chr_write(so->extra, buf, len);
+        return len;
+    }
+
+    return send(so->s, buf, len, flags);
+}
+
+static struct socket *slirp_find_ctl_socket(int addr_low_byte, int guest_port)
+{
+    struct socket *so;
+
+    for (so = tcb.so_next; so != &tcb; so = so->so_next) {
+        if ((so->so_faddr.s_addr & htonl(0xffffff00)) == special_addr.s_addr &&
+            (ntohl(so->so_faddr.s_addr) & 0xff) == addr_low_byte &&
+            htons(so->so_fport) == guest_port)
+            return so;
+    }
+
+    return NULL;
+}
+
+size_t slirp_socket_can_recv(int addr_low_byte, int guest_port)
+{
+    struct iovec iov[2];
+    struct socket *so;
+
+    if (!link_up)
+        return 0;
+
+    so = slirp_find_ctl_socket(addr_low_byte, guest_port);
+
+    if (!so || so->so_state & SS_NOFDREF)
+        return 0;
+
+    if (!CONN_CANFRCV(so) || so->so_snd.sb_cc >= (so->so_snd.sb_datalen / 2))
+        return 0;
+
+    return sopreprbuf(so, iov, NULL);
+}
+
+void slirp_socket_recv(int addr_low_byte, int guest_port, const uint8_t *buf,
+                       int size)
+{
+    int ret;
+    struct socket *so = slirp_find_ctl_socket(addr_low_byte, guest_port);
+
+    if (!so)
+        return;
+
+    ret = soreadbuf(so, buf, size);
+
+    if (ret > 0)
+        tcp_output(sototcpcb(so));
+}
diff --git a/socket.c b/socket.c
index 74560d7..f627eb0 100644
--- a/socket.c
+++ b/socket.c
@@ -5,13 +5,13 @@
  * terms and conditions of the copyright.
  */
 
+#include "qemu-common.h"
 #define WANT_SYS_IOCTL_H
 #include <slirp.h>
 #include "ip_icmp.h"
 #ifdef __sun__
 #include <sys/filio.h>
 #endif
-#include "qemu-common.h"
 
 static void sofcantrcvmore(struct socket *so);
 static void sofcantsendmore(struct socket *so);
@@ -83,29 +83,21 @@ void sofree(so) struct socket *so;
     free(so);
 }
 
-/*
- * Read from so's socket into sb_snd, updating all relevant sbuf fields
- * NOTE: This will only be called if it is select()ed for reading, so
- * a read() of 0 (or less) means it's disconnected
- */
-int soread(so) struct socket *so;
+size_t sopreprbuf(struct socket *so, struct iovec *iov, int *np)
 {
-    int n, nn, lss, total;
+    int n, lss, total;
     struct sbuf *sb = &so->so_snd;
     int len = sb->sb_datalen - sb->sb_cc;
-    struct iovec iov[2];
     int mss = so->so_tcpcb->t_maxseg;
 
-    DEBUG_CALL("soread");
+    DEBUG_CALL("sopreprbuf");
     DEBUG_ARG("so = %lx", (long)so);
 
-    /*
-     * No need to check if there's enough room to read.
-     * soread wouldn't have been called if there weren't
-     */
-
     len = sb->sb_datalen - sb->sb_cc;
 
+    if (len <= 0)
+        return 0;
+
     iov[0].iov_base = sb->sb_wptr;
     iov[1].iov_base = NULL;
     iov[1].iov_len = 0;
@@ -147,6 +139,31 @@ int soread(so) struct socket *so;
             n = 1;
         }
     }
+    if (np)
+        *np = n;
+
+    return iov[0].iov_len + (n - 1) * iov[1].iov_len;
+}
+
+/*
+ * Read from so's socket into sb_snd, updating all relevant sbuf fields
+ * NOTE: This will only be called if it is select()ed for reading, so
+ * a read() of 0 (or less) means it's disconnected
+ */
+int soread(so) struct socket *so;
+{
+    int n, nn;
+    struct sbuf *sb = &so->so_snd;
+    struct iovec iov[2];
+
+    DEBUG_CALL("soread");
+    DEBUG_ARG("so = %lx", (long)so);
+
+    /*
+     * No need to check if there's enough room to read.
+     * soread wouldn't have been called if there weren't
+     */
+    sopreprbuf(so, iov, &n);
 
 #ifdef HAVE_READV
     nn = readv(so->s, (struct iovec *)iov, n);
@@ -195,6 +212,48 @@ int soread(so) struct socket *so;
     return nn;
 }
 
+int soreadbuf(struct socket *so, const char *buf, int size)
+{
+    int n, nn, copy = size;
+    struct sbuf *sb = &so->so_snd;
+    struct iovec iov[2];
+
+    DEBUG_CALL("soreadbuf");
+    DEBUG_ARG("so = %lx", (long)so);
+
+    /*
+     * No need to check if there's enough room to read.
+     * soread wouldn't have been called if there weren't
+     */
+    if (sopreprbuf(so, iov, &n) < size)
+        goto err;
+
+    nn = MIN(iov[0].iov_len, copy);
+    memcpy(iov[0].iov_base, buf, nn);
+
+    copy -= nn;
+    buf += nn;
+
+    if (copy == 0)
+        goto done;
+
+    memcpy(iov[1].iov_base, buf, copy);
+
+done:
+    /* Update fields */
+    sb->sb_cc += size;
+    sb->sb_wptr += size;
+    if (sb->sb_wptr >= (sb->sb_data + sb->sb_datalen))
+        sb->sb_wptr -= sb->sb_datalen;
+    return size;
+err:
+
+    sofcantrcvmore(so);
+    tcp_sockclosed(sototcpcb(so));
+    fprintf(stderr, "soreadbuf buffer to small");
+    return -1;
+}
+
 /*
  * Get urgent data
  *
@@ -244,8 +303,8 @@ int sosendoob(so) struct socket *so;
 
     if (sb->sb_rptr < sb->sb_wptr) {
         /* We can send it directly */
-        n = send(so->s, sb->sb_rptr, so->so_urgc,
-                 (MSG_OOB)); /* |MSG_DONTWAIT)); */
+        n = slirp_send(so, sb->sb_rptr, so->so_urgc,
+                       (MSG_OOB)); /* |MSG_DONTWAIT)); */
         so->so_urgc -= n;
 
         DEBUG_MISC((dfd,
@@ -270,7 +329,7 @@ int sosendoob(so) struct socket *so;
             so->so_urgc -= n;
             len += n;
         }
-        n = send(so->s, buff, len, (MSG_OOB)); /* |MSG_DONTWAIT)); */
+        n = slirp_send(so, buff, len, (MSG_OOB)); /* |MSG_DONTWAIT)); */
 #ifdef DEBUG
         if (n != len)
             DEBUG_ERROR((dfd, "Didn't send all data urgently XXXXX\n"));
@@ -345,7 +404,7 @@ int sowrite(so) struct socket *so;
 
     DEBUG_MISC((dfd, "  ... wrote nn = %d bytes\n", nn));
 #else
-    nn = send(so->s, iov[0].iov_base, iov[0].iov_len, 0);
+    nn = slirp_send(so, iov[0].iov_base, iov[0].iov_len, 0);
 #endif
     /* This should never happen, but people tell me it does *shrug* */
     if (nn < 0 && (errno == EAGAIN || errno == EINTR))
@@ -363,7 +422,7 @@ int sowrite(so) struct socket *so;
 #ifndef HAVE_READV
     if (n == 2 && nn == iov[0].iov_len) {
         int ret;
-        ret = send(so->s, iov[1].iov_base, iov[1].iov_len, 0);
+        ret = slirp_send(so, iov[1].iov_base, iov[1].iov_len, 0);
         if (ret > 0)
             nn += ret;
     }
diff --git a/socket.h b/socket.h
index 9645577..3c5d625 100644
--- a/socket.h
+++ b/socket.h
@@ -95,5 +95,7 @@ void soisfconnecting _P((register struct socket *));
 void soisfconnected _P((register struct socket *));
 void soisfdisconnected _P((struct socket *));
 void sofwdrain _P((struct socket *));
+size_t sopreprbuf(struct socket *so, struct iovec *iov, int *np);
+int soreadbuf(struct socket *so, const char *buf, int size);
 
 #endif /* _SOCKET_H_ */
diff --git a/tcp_subr.c b/tcp_subr.c
index d41ef44..86946a9 100644
--- a/tcp_subr.c
+++ b/tcp_subr.c
@@ -1271,6 +1271,11 @@ int tcp_ctl(so) struct socket *so;
         for (ex_ptr = exec_list; ex_ptr; ex_ptr = ex_ptr->ex_next) {
             if (ex_ptr->ex_fport == so->so_fport &&
                 command == ex_ptr->ex_addr) {
+                if (ex_ptr->ex_pty == 3) {
+                    so->s = -1;
+                    so->extra = ex_ptr->ex_exec;
+                    return 1;
+                }
                 do_pty = ex_ptr->ex_pty;
                 goto do_exec;
             }