From f6388b2bf63df4d6ea452770541ac8d79c6a817e Mon Sep 17 00:00:00 2001
From: Fabrizio Bertocci <fabriziobertocci@gmail.com>
Date: Thu, 13 May 2021 08:55:10 -0400
Subject: [PATCH] Added some debugging printf to troubleshoot issue for BSD

---
 libc/calls/ioctl-siocgifconf.c | 67 ++++++++++++++++++++++++++++++----
 1 file changed, 60 insertions(+), 7 deletions(-)

diff --git a/libc/calls/ioctl-siocgifconf.c b/libc/calls/ioctl-siocgifconf.c
index 9896185c2..e967c3f9f 100644
--- a/libc/calls/ioctl-siocgifconf.c
+++ b/libc/calls/ioctl-siocgifconf.c
@@ -16,24 +16,77 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/bits/weaken.h"
+#include "libc/sysv/errfuns.h"
 #include "libc/calls/internal.h"
 #include "libc/sock/sock.h"
 #include "libc/sock/internal.h"
 #include "libc/sysv/consts/sio.h"
 
+
+#include "libc/stdio/stdio.h"
+#define PRINTF  weaken(printf)
+
+/* SIOCGIFCONF:
+ * Takes an struct ifconf object of a given size
+ * Modifies the following:
+ *  - ifc_len: set it to the number of valid ifreq structures representing
+ *    the interfaces
+ *  - ifc_ifcu.ifcu_req: sets the name of the interface for each interface
+ * The ifc_len is an input/output parameter: set it to the total size of 
+ * the ifcu_buf (ifcu_req) buffer on input.
+ */
 int ioctl_siocgifconf_nt(int, struct ifconf *) hidden;
 
 static int ioctl_siocgifconf_sysv(int fd, struct ifconf *ifc) {
   /* Same as the default for now... */
-  return sys_ioctl(fd, SIOCGIFCONF, ifc);
-  /*
-  int rc;
+  if (IsBsd()) {
+    if (!weaken(malloc)) {
+      return enomem();
+    } else {
+      /* On BSD the size of the struct ifreq is smaller (16 bytes
+       * instead of 24 bytes), so buffers need to be adjusted accordingly
+       *
+       * TODO: Since BSD requires a SMALLER buffer we don't need to 
+       *       malloc a temp buffer, insted reuse the same buffer and
+       *       safely move overlapping ifrn_name chunks
+       */
+      int i;
+      struct ifconf ifc_bsd;
+      size_t num_ifreq = ifc->ifc_len / sizeof(struct ifreq);
 
-  if ((rc = sys_ioctl(fd, SIOCGIFCONF, &ifc)) != -1) {
-    return rc;
+      PRINTF("Mac version!\n");
+      ifc_bsd.ifc_len = (num_ifreq * sizeof(struct ifreq_bsd));    /* Adjust max buffer */
+      ifc_bsd.ifc_buf = weaken(malloc)(ifc_bsd.ifc_len);
+      PRINTF("numInterf Linux=%lu\n", num_ifreq);
+      PRINTF("BSD   size=%lu\n", ifc_bsd.ifc_len);
+      PRINTF("Linux size=%lu\n", ifc->ifc_len);
+      if (!ifc_bsd.ifc_buf) {
+        PRINTF("Malloc failed\n");
+        return enomem();
+      }
+      PRINTF("Calling ioctl()\n");
+      i = sys_ioctl(fd, SIOCGIFCONF, &ifc_bsd);
+      PRINTF("rc=%d\n", i);
+      if (i < 0) {
+        weaken(free)(ifc_bsd.ifc_buf);
+        return -1;
+      }
+
+      /* Number of interfaces returned */
+      num_ifreq = ifc_bsd.ifc_len / sizeof(struct ifreq_bsd);
+      for (i = 1; i < num_ifreq; ++i) {
+        /* The first interface always match the same position */
+        memcpy(ifc->ifc_req[i].ifr_name, ifc_bsd.ifc_req[i].ifr_name, IFNAMSIZ);
+      }
+      ifc->ifc_len = num_ifreq * sizeof(struct ifreq);
+      weaken(free)(ifc_bsd.ifc_buf);
+      return 0;
+    }
+  } else {
+    // 100% compatible with Linux
+    return sys_ioctl(fd, SIOCGIFCONF, ifc);
   }
-  return rc;
-  */
 }
 
 /**