add strncpy / PSUTIL_STRNCPY variant which adds null terminator (fix gcc-9 warning)

5 files changed, 13 insertions, 8 deletions

diff --git a/psutil/_psutil_aix.c b/psutil/_psutil_aix.c
index cf79d307..791e831e 100644
--- a/psutil/_psutil_aix.c
+++ b/psutil/_psutil_aix.c
@@ -679,7 +679,7 @@ psutil_net_if_stats(PyObject* self, PyObject* args) {
     if (sock == -1)
         goto error;
 
-    strncpy(ifr.ifr_name, nic_name, sizeof(ifr.ifr_name));
+    PSUTIL_STRNCPY(ifr.ifr_name, nic_name, sizeof(ifr.ifr_name));
 
     // is up?
     ret = ioctl(sock, SIOCGIFFLAGS, &ifr);
diff --git a/psutil/_psutil_common.h b/psutil/_psutil_common.h
index 34c428c0..2408c9f6 100644
--- a/psutil/_psutil_common.h
+++ b/psutil/_psutil_common.h
@@ -15,6 +15,11 @@ extern int PSUTIL_DEBUG;
 // a signaler for connections without an actual status
 static const int PSUTIL_CONN_NONE = 128;
 
+// strncpy() variant which appends a null terminator.
+#define PSUTIL_STRNCPY(dst, src, n) \
+    strncpy(dst, src, n - 1); \
+    dst[n - 1] = '\0'
+
 // ====================================================================
 // --- Backward compatibility with missing Python.h APIs
 // ====================================================================
diff --git a/psutil/_psutil_linux.c b/psutil/_psutil_linux.c
index 5f00454b..49e86997 100644
--- a/psutil/_psutil_linux.c
+++ b/psutil/_psutil_linux.c
@@ -500,7 +500,7 @@ psutil_net_if_duplex_speed(PyObject* self, PyObject* args) {
     sock = socket(AF_INET, SOCK_DGRAM, 0);
     if (sock == -1)
         return PyErr_SetFromOSErrnoWithSyscall("socket()");
-    strncpy(ifr.ifr_name, nic_name, sizeof(ifr.ifr_name));
+    PSUTIL_STRNCPY(ifr.ifr_name, nic_name, sizeof(ifr.ifr_name));
 
     // duplex and speed
     memset(&ethcmd, 0, sizeof ethcmd);
diff --git a/psutil/_psutil_posix.c b/psutil/_psutil_posix.c
index 38483b3b..f7f8b92d 100644
--- a/psutil/_psutil_posix.c
+++ b/psutil/_psutil_posix.c
@@ -356,10 +356,10 @@ psutil_net_if_mtu(PyObject *self, PyObject *args) {
         goto error;
 
 #ifdef PSUTIL_SUNOS10
-    strncpy(lifr.lifr_name, nic_name, sizeof(lifr.lifr_name));
+    PSUTIL_STRNCPY(lifr.lifr_name, nic_name, sizeof(lifr.lifr_name));
     ret = ioctl(sock, SIOCGIFMTU, &lifr);
 #else
-    strncpy(ifr.ifr_name, nic_name, sizeof(ifr.ifr_name));
+    PSUTIL_STRNCPY(ifr.ifr_name, nic_name, sizeof(ifr.ifr_name));
     ret = ioctl(sock, SIOCGIFMTU, &ifr);
 #endif
     if (ret == -1)
@@ -398,7 +398,7 @@ psutil_net_if_flags(PyObject *self, PyObject *args) {
     if (sock == -1)
         goto error;
 
-    strncpy(ifr.ifr_name, nic_name, sizeof(ifr.ifr_name));
+    PSUTIL_STRNCPY(ifr.ifr_name, nic_name, sizeof(ifr.ifr_name));
     ret = ioctl(sock, SIOCGIFFLAGS, &ifr);
     if (ret == -1)
         goto error;
@@ -578,7 +578,7 @@ psutil_net_if_duplex_speed(PyObject *self, PyObject *args) {
     sock = socket(AF_INET, SOCK_DGRAM, 0);
     if (sock == -1)
         return PyErr_SetFromErrno(PyExc_OSError);
-    strncpy(ifr.ifr_name, nic_name, sizeof(ifr.ifr_name));
+    PSUTIL_STRNCPY(ifr.ifr_name, nic_name, sizeof(ifr.ifr_name));
 
     // speed / duplex
     memset(&ifmed, 0, sizeof(struct ifmediareq));
diff --git a/psutil/_psutil_sunos.c b/psutil/_psutil_sunos.c
index 6548640b..82114c8c 100644
--- a/psutil/_psutil_sunos.c
+++ b/psutil/_psutil_sunos.c
@@ -1024,7 +1024,7 @@ psutil_net_io_counters(PyObject *self, PyObject *args) {
             goto next;
 
         // check if this is a network interface by sending a ioctl
-        strncpy(ifr.lifr_name, ksp->ks_name, sizeof(ifr.lifr_name));
+        PSUTIL_STRNCPY(ifr.lifr_name, ksp->ks_name, sizeof(ifr.lifr_name));
         ret = ioctl(sock, SIOCGLIFFLAGS, &ifr);
         if (ret == -1)
             goto next;
@@ -1515,7 +1515,7 @@ psutil_net_if_stats(PyObject* self, PyObject* args) {
             if (strcmp(ksp->ks_class, "net") != 0)
                 continue;
 
-            strncpy(ifr.lifr_name, ksp->ks_name, sizeof(ifr.lifr_name));
+            PSUTIL_STRNCPY(ifr.lifr_name, ksp->ks_name, sizeof(ifr.lifr_name));
             ret = ioctl(sock, SIOCGLIFFLAGS, &ifr);
             if (ret == -1)
                 continue;  // not a network interface