[3.6] bpo-31927: Fix bugs in socketmodule.c on NetBSD and other issues. (GH-4235) (#4352)

* Fix compilation of the socket module on NetBSD 8.
* Fix the assertion failure or reading arbitrary data when parse
  a AF_BLUETOOTH address on NetBSD and DragonFly BSD.
* Fix other potential errors and make the code more reliable.
(cherry picked from commit d3187158c09cf899e9849f335bdff10594209167)

2 files changed, 61 insertions, 58 deletions

diff --git a/Modules/socketmodule.c b/Modules/socketmodule.c
index da84291..968dad0 100644
--- a/Modules/socketmodule.c
+++ b/Modules/socketmodule.c
@@ -240,7 +240,7 @@ http://cvsweb.netbsd.org/bsdweb.cgi/src/lib/libc/net/getaddrinfo.c.diff?r1=1.82&
 # include <ctype.h>
 #endif
 
-#ifdef __APPLE__
+#if defined(__APPLE__) || defined(__NetBSD__)
 # include <sys/ioctl.h>
 #endif
 
@@ -1250,7 +1250,7 @@ makesockaddr(SOCKET_T sockfd, struct sockaddr *addr, size_t addrlen, int proto)
         }
         return ret;
     }
-#endif
+#endif /* ENABLE_IPV6 */
 
 #ifdef USE_BLUETOOTH
     case AF_BLUETOOTH:
@@ -1289,11 +1289,11 @@ makesockaddr(SOCKET_T sockfd, struct sockaddr *addr, size_t addrlen, int proto)
             struct sockaddr_hci *a = (struct sockaddr_hci *) addr;
 #if defined(__NetBSD__) || defined(__DragonFly__)
             return makebdaddr(&_BT_HCI_MEMB(a, bdaddr));
-#else
+#else /* __NetBSD__ || __DragonFly__ */
             PyObject *ret = NULL;
             ret = Py_BuildValue("i", _BT_HCI_MEMB(a, dev));
             return ret;
-#endif
+#endif /* !(__NetBSD__ || __DragonFly__) */
         }
 
 #if !defined(__FreeBSD__)
@@ -1302,20 +1302,20 @@ makesockaddr(SOCKET_T sockfd, struct sockaddr *addr, size_t addrlen, int proto)
             struct sockaddr_sco *a = (struct sockaddr_sco *) addr;
             return makebdaddr(&_BT_SCO_MEMB(a, bdaddr));
         }
-#endif
+#endif /* !__FreeBSD__ */
 
         default:
             PyErr_SetString(PyExc_ValueError,
                             "Unknown Bluetooth protocol");
             return NULL;
         }
-#endif
+#endif /* USE_BLUETOOTH */
 
 #if defined(HAVE_NETPACKET_PACKET_H) && defined(SIOCGIFNAME)
     case AF_PACKET:
     {
         struct sockaddr_ll *a = (struct sockaddr_ll *)addr;
-        char *ifname = "";
+        const char *ifname = "";
         struct ifreq ifr;
         /* need to look up interface name give index */
         if (a->sll_ifindex) {
@@ -1331,7 +1331,7 @@ makesockaddr(SOCKET_T sockfd, struct sockaddr *addr, size_t addrlen, int proto)
                              a->sll_addr,
                              a->sll_halen);
     }
-#endif
+#endif /* HAVE_NETPACKET_PACKET_H && SIOCGIFNAME */
 
 #ifdef HAVE_LINUX_TIPC_H
     case AF_TIPC:
@@ -1364,13 +1364,13 @@ makesockaddr(SOCKET_T sockfd, struct sockaddr *addr, size_t addrlen, int proto)
             return NULL;
         }
     }
-#endif
+#endif /* HAVE_LINUX_TIPC_H */
 
-#ifdef AF_CAN
+#if defined(AF_CAN) && defined(SIOCGIFNAME)
     case AF_CAN:
     {
         struct sockaddr_can *a = (struct sockaddr_can *)addr;
-        char *ifname = "";
+        const char *ifname = "";
         struct ifreq ifr;
         /* need to look up interface name given index */
         if (a->can_ifindex) {
@@ -1383,7 +1383,7 @@ makesockaddr(SOCKET_T sockfd, struct sockaddr *addr, size_t addrlen, int proto)
                                     ifname,
                                     a->can_family);
     }
-#endif
+#endif /* AF_CAN && SIOCGIFNAME */
 
 #ifdef PF_SYSTEM
     case PF_SYSTEM:
@@ -1394,13 +1394,13 @@ makesockaddr(SOCKET_T sockfd, struct sockaddr *addr, size_t addrlen, int proto)
             struct sockaddr_ctl *a = (struct sockaddr_ctl *)addr;
             return Py_BuildValue("(II)", a->sc_id, a->sc_unit);
         }
-#endif
+#endif /* SYSPROTO_CONTROL */
         default:
             PyErr_SetString(PyExc_ValueError,
                             "Invalid address type");
             return 0;
         }
-#endif
+#endif /* PF_SYSTEM */
 
 #ifdef HAVE_SOCKADDR_ALG
     case AF_ALG:
@@ -1416,7 +1416,7 @@ makesockaddr(SOCKET_T sockfd, struct sockaddr *addr, size_t addrlen, int proto)
             a->salg_feat,
             a->salg_mask);
     }
-#endif
+#endif /* HAVE_SOCKADDR_ALG */
 
     /* More cases here... */
 
@@ -1582,12 +1582,12 @@ getsockaddrarg(PySocketSockObject *s, PyObject *args,
         *len_ret = sizeof(*addr);
         return 1;
     }
-#endif
+#endif /* AF_NETLINK */
 
 #ifdef AF_RDS
     case AF_RDS:
         /* RDS sockets use sockaddr_in: fall-through */
-#endif
+#endif /* AF_RDS */
 
     case AF_INET:
     {
@@ -1669,7 +1669,7 @@ getsockaddrarg(PySocketSockObject *s, PyObject *args,
         *len_ret = sizeof *addr;
         return 1;
     }
-#endif
+#endif /* ENABLE_IPV6 */
 
 #ifdef USE_BLUETOOTH
     case AF_BLUETOOTH:
@@ -1678,7 +1678,7 @@ getsockaddrarg(PySocketSockObject *s, PyObject *args,
         case BTPROTO_L2CAP:
         {
             struct sockaddr_l2 *addr;
-            char *straddr;
+            const char *straddr;
 
             addr = (struct sockaddr_l2 *)addr_ret;
             memset(addr, 0, sizeof(struct sockaddr_l2));
@@ -1698,7 +1698,7 @@ getsockaddrarg(PySocketSockObject *s, PyObject *args,
         case BTPROTO_RFCOMM:
         {
             struct sockaddr_rc *addr;
-            char *straddr;
+            const char *straddr;
 
             addr = (struct sockaddr_rc *)addr_ret;
             _BT_RC_MEMB(addr, family) = AF_BLUETOOTH;
@@ -1718,24 +1718,24 @@ getsockaddrarg(PySocketSockObject *s, PyObject *args,
         {
             struct sockaddr_hci *addr = (struct sockaddr_hci *)addr_ret;
 #if defined(__NetBSD__) || defined(__DragonFly__)
-                        char *straddr = PyBytes_AS_STRING(args);
-
-                        _BT_HCI_MEMB(addr, family) = AF_BLUETOOTH;
-            if (straddr == NULL) {
+            const char *straddr;
+            _BT_HCI_MEMB(addr, family) = AF_BLUETOOTH;
+            if (!PyBytes_Check(args)) {
                 PyErr_SetString(PyExc_OSError, "getsockaddrarg: "
                     "wrong format");
                 return 0;
             }
+            straddr = PyBytes_AS_STRING(args);
             if (setbdaddr(straddr, &_BT_HCI_MEMB(addr, bdaddr)) < 0)
                 return 0;
-#else
+#else  /* __NetBSD__ || __DragonFly__ */
             _BT_HCI_MEMB(addr, family) = AF_BLUETOOTH;
             if (!PyArg_ParseTuple(args, "i", &_BT_HCI_MEMB(addr, dev))) {
                 PyErr_SetString(PyExc_OSError, "getsockaddrarg: "
                                 "wrong format");
                 return 0;
             }
-#endif
+#endif /* !(__NetBSD__ || __DragonFly__) */
             *len_ret = sizeof *addr;
             return 1;
         }
@@ -1743,7 +1743,7 @@ getsockaddrarg(PySocketSockObject *s, PyObject *args,
         case BTPROTO_SCO:
         {
             struct sockaddr_sco *addr;
-            char *straddr;
+            const char *straddr;
 
             addr = (struct sockaddr_sco *)addr_ret;
             _BT_SCO_MEMB(addr, family) = AF_BLUETOOTH;
@@ -1759,20 +1759,20 @@ getsockaddrarg(PySocketSockObject *s, PyObject *args,
             *len_ret = sizeof *addr;
             return 1;
         }
-#endif
+#endif /* !__FreeBSD__ */
         default:
             PyErr_SetString(PyExc_OSError, "getsockaddrarg: unknown Bluetooth protocol");
             return 0;
         }
     }
-#endif
+#endif /* USE_BLUETOOTH */
 
 #if defined(HAVE_NETPACKET_PACKET_H) && defined(SIOCGIFINDEX)
     case AF_PACKET:
     {
         struct sockaddr_ll* addr;
         struct ifreq ifr;
-        char *interfaceName;
+        const char *interfaceName;
         int protoNumber;
         int hatype = 0;
         int pkttype = 0;
@@ -1826,7 +1826,7 @@ getsockaddrarg(PySocketSockObject *s, PyObject *args,
         PyBuffer_Release(&haddr);
         return 1;
     }
-#endif
+#endif /* HAVE_NETPACKET_PACKET_H && SIOCGIFINDEX */
 
 #ifdef HAVE_LINUX_TIPC_H
     case AF_TIPC:
@@ -1876,9 +1876,9 @@ getsockaddrarg(PySocketSockObject *s, PyObject *args,
 
         return 1;
     }
-#endif
+#endif /* HAVE_LINUX_TIPC_H */
 
-#if defined(AF_CAN) && defined(CAN_RAW) && defined(CAN_BCM)
+#if defined(AF_CAN) && defined(CAN_RAW) && defined(CAN_BCM) && defined(SIOCGIFINDEX)
     case AF_CAN:
         switch (s->sock_proto) {
         case CAN_RAW:
@@ -1927,7 +1927,7 @@ getsockaddrarg(PySocketSockObject *s, PyObject *args,
                             "getsockaddrarg: unsupported CAN protocol");
             return 0;
         }
-#endif
+#endif /* AF_CAN && CAN_RAW && CAN_BCM && SIOCGIFINDEX */
 
 #ifdef PF_SYSTEM
     case PF_SYSTEM:
@@ -1979,19 +1979,19 @@ getsockaddrarg(PySocketSockObject *s, PyObject *args,
             *len_ret = sizeof(*addr);
             return 1;
         }
-#endif
+#endif /* SYSPROTO_CONTROL */
         default:
             PyErr_SetString(PyExc_OSError,
                             "getsockaddrarg: unsupported PF_SYSTEM protocol");
             return 0;
         }
-#endif
+#endif /* PF_SYSTEM */
 #ifdef HAVE_SOCKADDR_ALG
     case AF_ALG:
     {
         struct sockaddr_alg *sa;
-        char *type;
-        char *name;
+        const char *type;
+        const char *name;
         sa = (struct sockaddr_alg *)addr_ret;
 
         memset(sa, 0, sizeof(*sa));
@@ -2015,7 +2015,7 @@ getsockaddrarg(PySocketSockObject *s, PyObject *args,
         *len_ret = sizeof(*sa);
         return 1;
     }
-#endif
+#endif /* HAVE_SOCKADDR_ALG */
 
     /* More cases here... */
 
@@ -2050,12 +2050,12 @@ getsockaddrlen(PySocketSockObject *s, socklen_t *len_ret)
         *len_ret = sizeof (struct sockaddr_nl);
         return 1;
     }
-#endif
+#endif /* AF_NETLINK */
 
 #ifdef AF_RDS
     case AF_RDS:
         /* RDS sockets use sockaddr_in: fall-through */
-#endif
+#endif /* AF_RDS */
 
     case AF_INET:
     {
@@ -2069,7 +2069,7 @@ getsockaddrlen(PySocketSockObject *s, socklen_t *len_ret)
         *len_ret = sizeof (struct sockaddr_in6);
         return 1;
     }
-#endif
+#endif /* ENABLE_IPV6 */
 
 #ifdef USE_BLUETOOTH
     case AF_BLUETOOTH:
@@ -2090,7 +2090,7 @@ getsockaddrlen(PySocketSockObject *s, socklen_t *len_ret)
         case BTPROTO_SCO:
             *len_ret = sizeof (struct sockaddr_sco);
             return 1;
-#endif
+#endif /* !__FreeBSD__ */
         default:
             PyErr_SetString(PyExc_OSError, "getsockaddrlen: "
                             "unknown BT protocol");
@@ -2098,7 +2098,7 @@ getsockaddrlen(PySocketSockObject *s, socklen_t *len_ret)
 
         }
     }
-#endif
+#endif /* USE_BLUETOOTH */
 
 #ifdef HAVE_NETPACKET_PACKET_H
     case AF_PACKET:
@@ -2106,7 +2106,7 @@ getsockaddrlen(PySocketSockObject *s, socklen_t *len_ret)
         *len_ret = sizeof (struct sockaddr_ll);
         return 1;
     }
-#endif
+#endif /* HAVE_NETPACKET_PACKET_H */
 
 #ifdef HAVE_LINUX_TIPC_H
     case AF_TIPC:
@@ -2114,7 +2114,7 @@ getsockaddrlen(PySocketSockObject *s, socklen_t *len_ret)
         *len_ret = sizeof (struct sockaddr_tipc);
         return 1;
     }
-#endif
+#endif /* HAVE_LINUX_TIPC_H */
 
 #ifdef AF_CAN
     case AF_CAN:
@@ -2122,7 +2122,7 @@ getsockaddrlen(PySocketSockObject *s, socklen_t *len_ret)
         *len_ret = sizeof (struct sockaddr_can);
         return 1;
     }
-#endif
+#endif /* AF_CAN */
 
 #ifdef PF_SYSTEM
     case PF_SYSTEM:
@@ -2131,20 +2131,20 @@ getsockaddrlen(PySocketSockObject *s, socklen_t *len_ret)
         case SYSPROTO_CONTROL:
             *len_ret = sizeof (struct sockaddr_ctl);
             return 1;
-#endif
+#endif /* SYSPROTO_CONTROL */
         default:
             PyErr_SetString(PyExc_OSError, "getsockaddrlen: "
                             "unknown PF_SYSTEM protocol");
             return 0;
         }
-#endif
+#endif /* PF_SYSTEM */
 #ifdef HAVE_SOCKADDR_ALG
     case AF_ALG:
     {
         *len_ret = sizeof (struct sockaddr_alg);
         return 1;
     }
-#endif
+#endif /* HAVE_SOCKADDR_ALG */
 
     /* More cases here... */
 
@@ -5178,7 +5178,7 @@ socket_gethostbyaddr(PyObject *self, PyObject *args)
     int result;
 #endif
 #endif /* HAVE_GETHOSTBYNAME_R */
-    char *ap;
+    const char *ap;
     int al;
     int af;
 
@@ -5250,7 +5250,7 @@ for a host.  The host argument is a string giving a host name or IP number.");
 static PyObject *
 socket_getservbyname(PyObject *self, PyObject *args)
 {
-    char *name, *proto=NULL;
+    const char *name, *proto=NULL;
     struct servent *sp;
     if (!PyArg_ParseTuple(args, "s|s:getservbyname", &name, &proto))
         return NULL;
@@ -5281,7 +5281,7 @@ static PyObject *
 socket_getservbyport(PyObject *self, PyObject *args)
 {
     int port;
-    char *proto=NULL;
+    const char *proto=NULL;
     struct servent *sp;
     if (!PyArg_ParseTuple(args, "i|s:getservbyport", &port, &proto))
         return NULL;
@@ -5316,7 +5316,7 @@ otherwise any protocol will match.");
 static PyObject *
 socket_getprotobyname(PyObject *self, PyObject *args)
 {
-    char *name;
+    const char *name;
     struct protoent *sp;
     if (!PyArg_ParseTuple(args, "s:getprotobyname", &name))
         return NULL;
@@ -5614,7 +5614,7 @@ socket_inet_aton(PyObject *self, PyObject *args)
     /* Have to use inet_addr() instead */
     unsigned int packed_addr;
 #endif
-    char *ip_addr;
+    const char *ip_addr;
 
     if (!PyArg_ParseTuple(args, "s:inet_aton", &ip_addr))
         return NULL;
@@ -5709,7 +5709,7 @@ static PyObject *
 socket_inet_pton(PyObject *self, PyObject *args)
 {
     int af;
-    char* ip;
+    const char* ip;
     int retval;
 #ifdef ENABLE_IPV6
     char packed[Py_MAX(sizeof(struct in_addr), sizeof(struct in6_addr))];
@@ -6046,7 +6046,7 @@ socket_getnameinfo(PyObject *self, PyObject *args)
 {
     PyObject *sa = (PyObject *)NULL;
     int flags;
-    char *hostp;
+    const char *hostp;
     int port;
     unsigned int flowinfo, scope_id;
     char hbuf[NI_MAXHOST], pbuf[NI_MAXSERV];
diff --git a/Modules/socketmodule.h b/Modules/socketmodule.h
index 03f982b..af7c36a 100644
--- a/Modules/socketmodule.h
+++ b/Modules/socketmodule.h
@@ -80,7 +80,10 @@ typedef int socklen_t;
 #endif
 
 #ifdef HAVE_LINUX_CAN_H
-#include <linux/can.h>
+# include <linux/can.h>
+#else
+# undef AF_CAN
+# undef PF_CAN
 #endif
 
 #ifdef HAVE_LINUX_CAN_RAW_H