[Qemu-devel] [PATCH v3 1/5] Redirect slirp traffic to/from qemu character device.

[Gleb Natapov]

Signed-off-by: Gleb Natapov <address@hidden>
---

 slirp/libslirp.h |    5 ++-
 slirp/main.h     |    1 +
 slirp/misc.c     |    2 +
 slirp/sbuf.c     |    2 +
 slirp/slirp.c    |   63 +++++++++++++++++++++++++++++++++-
 slirp/socket.c   |  101 +++++++++++++++++++++++++++++++++++++++++++-----------
 slirp/socket.h   |    2 +
 slirp/tcp_subr.c |    5 +++
 8 files changed, 156 insertions(+), 25 deletions(-)

diff --git a/slirp/libslirp.h b/slirp/libslirp.h
index 7e4cfa9..16a817a 100644
--- a/slirp/libslirp.h
+++ b/slirp/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/slirp/main.h b/slirp/main.h
index c01adda..3ef2996 100644
--- a/slirp/main.h
+++ b/slirp/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/slirp/misc.c b/slirp/misc.c
index 9ff3176..1ec8b55 100644
--- a/slirp/misc.c
+++ b/slirp/misc.c
@@ -169,7 +169,7 @@ add_exec(ex_ptr, do_pty, exec, addr, 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/slirp/sbuf.c b/slirp/sbuf.c
index b0e0838..2e6e2b2 100644
--- a/slirp/sbuf.c
+++ b/slirp/sbuf.c
@@ -108,7 +108,7 @@ sbappend(so, 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/slirp.c b/slirp/slirp.c
index 17b40e2..f6f94e4 100644
--- a/slirp/slirp.c
+++ b/slirp/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 */
@@ -736,9 +737,69 @@ int slirp_redir(int is_udp, int host_port,
     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/slirp/socket.c b/slirp/socket.c
index 00694e2..9def541 100644
--- a/slirp/socket.c
+++ b/slirp/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);
@@ -91,31 +91,21 @@ sofree(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;
@@ -156,6 +146,33 @@ soread(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);
@@ -202,6 +219,48 @@ soread(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
  *
@@ -255,7 +314,7 @@ sosendoob(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, " --- sent %d bytes urgent data, %d urgent 
bytes left\n", n, so->so_urgc));
@@ -276,7 +335,7 @@ sosendoob(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"));
@@ -348,7 +407,7 @@ sowrite(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))
@@ -365,7 +424,7 @@ sowrite(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/slirp/socket.h b/slirp/socket.h
index 5edea90..72b473d 100644
--- a/slirp/socket.h
+++ b/slirp/socket.h
@@ -87,5 +87,7 @@ 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/slirp/tcp_subr.c b/slirp/tcp_subr.c
index bce07a6..12abebe 100644
--- a/slirp/tcp_subr.c
+++ b/slirp/tcp_subr.c
@@ -1281,6 +1281,11 @@ tcp_ctl(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;
                        }