kern_proc - add kern.proc.cwd sysctl

* Add a kern.proc.cwd sysctl to be able to get the cwd of processes.
  Many terminal emulators need something this to set a window title.
  Right now, some simply don't work (konsole) and others (Terminal) use
  linprocfs.

diff --git a/sys/kern/kern_proc.c b/sys/kern/kern_proc.c
index 8bf06a7..bcd8034 100644 (file)
--- a/sys/kern/kern_proc.c
+++ b/sys/kern/kern_proc.c
@@ -983,6 +983,48 @@ done:
        return (error);
 }
 
+static int
+sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS)
+{
+       int *name = (int*) arg1;
+       u_int namelen = arg2;
+       struct proc *p;
+       int error = 0;
+       char *fullpath, *freepath;
+       struct ucred *cr1 = curproc->p_ucred;
+
+       if (namelen != 1) 
+               return (EINVAL);
+
+       lwkt_gettoken(&proc_token);
+       p = pfind((pid_t)name[0]);
+       if (p == NULL)
+               goto done;
+
+       /*
+        * If we are not allowed to see other args, we certainly shouldn't
+        * get the cwd either. Also check the usual trespassing.
+        */
+       if ((!ps_argsopen) && p_trespass(cr1, p->p_ucred))
+               goto done;
+
+       PHOLD(p);
+       if (req->oldptr && p->p_fd != NULL) {
+               error = cache_fullpath(p, &p->p_fd->fd_ncdir,
+                   &fullpath, &freepath, 0);
+               if (error)
+                       goto done;
+               error = SYSCTL_OUT(req, fullpath, strlen(fullpath) + 1);
+               kfree(freepath, M_TEMP);
+       }
+
+       PRELE(p);
+
+done:
+       lwkt_reltoken(&proc_token);
+       return (error);
+}
+
 SYSCTL_NODE(_kern, KERN_PROC, proc, CTLFLAG_RD,  0, "Process table");
 
 SYSCTL_PROC(_kern_proc, KERN_PROC_ALL, all, CTLFLAG_RD|CTLTYPE_STRUCT,
@@ -1023,3 +1065,6 @@ SYSCTL_NODE(_kern_proc, (KERN_PROC_PID | KERN_PROC_FLAG_LWP), pid_lwp, CTLFLAG_R
 
 SYSCTL_NODE(_kern_proc, KERN_PROC_ARGS, args, CTLFLAG_RW | CTLFLAG_ANYBODY,
        sysctl_kern_proc_args, "Process argument list");
+
+SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD | CTLFLAG_ANYBODY,
+       sysctl_kern_proc_cwd, "Process argument list");

diff --git a/sys/sys/sysctl.h b/sys/sys/sysctl.h
index 8c9deaa..94b8d96 100644 (file)
--- a/sys/sys/sysctl.h
+++ b/sys/sys/sysctl.h
@@ -432,6 +432,7 @@ TAILQ_HEAD(sysctl_ctx_list, sysctl_ctx_entry);
 #define        KERN_PROC_UID           5       /* by effective uid */
 #define        KERN_PROC_RUID          6       /* by real uid */
 #define        KERN_PROC_ARGS          7       /* get/set arguments/proctitle */
+#define        KERN_PROC_CWD           8       /* get cwd */
 
 #define KERN_PROC_FLAGMASK     0x10
 #define KERN_PROC_FLAG_LWP     0x10