Implement Process.environ() on *BSD family

Tested-on: FreeBSD-13-CURRENT (r363681), FreeBSD-12.1,
           FreeBSD-11.4, FreeBSD-11.3, FreeBSD-10.4,
           FreeBSD-9.3, FreeBSD-8.4, FreeBSD-7.1, FreeBSD-6.4,
           OpenBSD-6.7, OpenBSD-5.7, NetBSD-9.0, NetBSD-8.2

psutil/_psbsd.py

@@ -668,6 +668,10 @@ def cmdline(self):
         else:
             return cext.proc_cmdline(self.pid)
 
+    @wrap_exceptions
+    def environ(self):
+        return cext.proc_environ(self.pid)
+
     @wrap_exceptions
     def terminal(self):
         tty_nr = self.oneshot()[kinfo_proc_map['ttynr']]

psutil/_psutil_bsd.c

@@ -57,6 +57,7 @@
 #include <net/route.h>
 #include <netinet/in.h>   // process open files/connections
 #include <sys/un.h>
+#include <kvm.h>
 
 #include "_psutil_common.h"
 #include "_psutil_posix.h"
@@ -74,6 +75,10 @@
     #else
         #include <utmpx.h>
     #endif
+    #include <fcntl.h>
+    #include <sys/param.h>
+    #include <sys/sysctl.h>
+    #include <sys/user.h>
 #elif PSUTIL_OPENBSD
     #include "arch/openbsd/specific.h"
 
@@ -391,6 +396,109 @@ psutil_proc_cmdline(PyObject *self, PyObject *args) {
 }
 
 
+/*
+ * Return process environment as a Python dictionary
+ */
+PyObject *
+psutil_proc_environ(PyObject *self, PyObject *args) {
+    unsigned int i, cnt = 0;
+    long pid;
+    char *s, **envs, errbuf[_POSIX2_LINE_MAX];
+    PyObject *py_err=NULL, *py_value=NULL, *py_retdict=NULL;
+    kvm_t *kd;
+#ifdef PSUTIL_NETBSD
+    struct kinfo_proc2 *p;
+#else
+    struct kinfo_proc *p;
+#endif
+
+    if (!PyArg_ParseTuple(args, "l", &pid))
+        return NULL;
+
+#if defined(PSUTIL_FREEBSD)
+    kd = kvm_openfiles(NULL, "/dev/null", NULL, 0, errbuf);
+#else
+    kd = kvm_openfiles(NULL, NULL, NULL, KVM_NO_FILES, errbuf);
+#endif
+    if (!kd) {
+        convert_kvm_err("kvm_openfiles", errbuf);
+        return NULL;
+    }
+
+    py_retdict = PyDict_New();
+    if (!py_retdict)
+        goto error;
+
+#if defined(PSUTIL_FREEBSD)
+    p = kvm_getprocs(kd, KERN_PROC_PID, pid, (int *)&cnt);
+#elif defined(PSUTIL_OPENBSD)
+    p = kvm_getprocs(kd, KERN_PROC_PID, pid, sizeof(*p), &cnt);
+#elif defined(PSUTIL_NETBSD)
+    p = kvm_getproc2(kd, KERN_PROC_PID, pid, sizeof(*p), &cnt);
+#endif
+    if (!p) {
+        py_err = NoSuchProcess("kvm_getprocs");
+        goto error;
+    }
+    if (!cnt) {
+        py_err = NoSuchProcess("kvm_getprocs: cnt==0");
+        goto error;
+    }
+
+    /* On *BSD kernels there are a few kernel-only system processes without an environment.
+     * To make unittest suite happy, return an empty environment
+     * (See e.g. "procstat -e 0 | 1 | 2 ..." on FreeBSD.)
+     */
+    if (p->ki_ppid == 0) {
+        /* Process is a direct [kernel-only] descendant of process 0 */
+        kvm_close(kd);
+        return py_retdict;
+    }
+
+
+#if defined(PSUTIL_NETBSD)
+    envs = kvm_getenvv2(kd, p, 0);
+#else
+    envs = kvm_getenvv(kd, p, 0);
+#endif
+    if (!envs) {
+        /* Map the most obvious stuff to general exceptions exported by "psutil" */
+        if (errno == EPERM)
+            py_err = AccessDenied("kvm_getenvv");
+        else if (errno == ESRCH)
+            py_err = NoSuchProcess("kvm_getenvv");
+        else
+            PyErr_SetFromErrno(PyExc_OSError);
+        goto error;
+    }
+
+    /* Indicate we need to return libpython error if we return failure */
+    errno = 0;
+
+    for (i = 0; envs[i] != NULL; i++) {
+        s = strchr(envs[i], '=');
+        if (!s)
+            continue;
+        *s++ = 0;
+        py_value = PyUnicode_DecodeFSDefault(s);
+        if (!py_value)
+            goto error;
+        if (PyDict_SetItemString(py_retdict, envs[i], py_value)) {
+            goto error;
+        }
+        Py_DECREF(py_value);
+    }
+
+    kvm_close(kd);
+    return py_retdict;
+
+error:
+    Py_XDECREF(py_value);
+    Py_XDECREF(py_retdict);
+    kvm_close(kd);
+    return py_err;
+}
+
 /*
  * Return the number of logical CPUs in the system.
  * XXX this could be shared with macOS
@@ -958,6 +1066,8 @@ static PyMethodDef mod_methods[] = {
     {"cpu_count_phys", psutil_cpu_count_phys, METH_VARARGS,
      "Return an XML string to determine the number physical CPUs."},
 #endif
+    {"proc_environ", psutil_proc_environ, METH_VARARGS,
+     "Return process environment"},
 
     // --- system-related functions
 

psutil/tests/test_contracts.py

@@ -137,7 +137,8 @@ class TestAvailProcessAPIs(PsutilTestCase):
 
     def test_environ(self):
         self.assertEqual(hasattr(psutil.Process, "environ"),
-                         LINUX or MACOS or WINDOWS or AIX or SUNOS)
+                         LINUX or MACOS or WINDOWS or AIX or SUNOS or
+                         FREEBSD or OPENBSD or NETBSD)
 
     def test_uids(self):
         self.assertEqual(hasattr(psutil.Process, "uids"), POSIX)