linux-user: Add setsockopt(SO_ATTACH_FILTER)

This is needed to be able to run dhclient.

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>

linux-user/syscall.c

@@ -106,6 +106,7 @@ int __clone2(int (*fn)(void *), void *child_stack_base,
 #include <linux/dm-ioctl.h>
 #include <linux/reboot.h>
 #include <linux/route.h>
+#include <linux/filter.h>
 #include "linux_loop.h"
 #include "cpu-uname.h"
 
@@ -1357,6 +1358,49 @@ set_timeout:
         case TARGET_SO_SNDTIMEO:
                 optname = SO_SNDTIMEO;
                 goto set_timeout;
+        case TARGET_SO_ATTACH_FILTER:
+        {
+                struct target_sock_fprog *tfprog;
+                struct target_sock_filter *tfilter;
+                struct sock_fprog fprog;
+                struct sock_filter *filter;
+                int i;
+
+                if (optlen != sizeof(*tfprog)) {
+                    return -TARGET_EINVAL;
+                }
+                if (!lock_user_struct(VERIFY_READ, tfprog, optval_addr, 0)) {
+                    return -TARGET_EFAULT;
+                }
+                if (!lock_user_struct(VERIFY_READ, tfilter,
+                                      tswapal(tfprog->filter), 0)) {
+                    unlock_user_struct(tfprog, optval_addr, 1);
+                    return -TARGET_EFAULT;
+                }
+
+                fprog.len = tswap16(tfprog->len);
+                filter = malloc(fprog.len * sizeof(*filter));
+                if (filter == NULL) {
+                    unlock_user_struct(tfilter, tfprog->filter, 1);
+                    unlock_user_struct(tfprog, optval_addr, 1);
+                    return -TARGET_ENOMEM;
+                }
+                for (i = 0; i < fprog.len; i++) {
+                    filter[i].code = tswap16(tfilter[i].code);
+                    filter[i].jt = tfilter[i].jt;
+                    filter[i].jf = tfilter[i].jf;
+                    filter[i].k = tswap32(tfilter[i].k);
+                }
+                fprog.filter = filter;
+
+                ret = get_errno(setsockopt(sockfd, SOL_SOCKET,
+                                SO_ATTACH_FILTER, &fprog, sizeof(fprog)));
+                free(filter);
+
+                unlock_user_struct(tfilter, tfprog->filter, 1);
+                unlock_user_struct(tfprog, optval_addr, 1);
+                return ret;
+        }
             /* Options with 'int' argument.  */
         case TARGET_SO_DEBUG:
 		optname = SO_DEBUG;

linux-user/syscall_defs.h

@@ -119,6 +119,18 @@ struct target_sockaddr {
     uint8_t sa_data[14];
 };
 
+struct target_sock_filter {
+    abi_ushort code;
+    uint8_t jt;
+    uint8_t jf;
+    abi_uint k;
+};
+
+struct target_sock_fprog {
+    abi_ushort len;
+    abi_ulong filter;
+};
+
 struct target_in_addr {
     uint32_t s_addr; /* big endian */
 };