*** empty log message ***

2002-01-05 21:05:59 +00:00
parent 48ff9f230b
commit 63a3c47e0c
1 changed files with 209 additions and 0 deletions
--- a/sys/unix/unixres.c
+++ b/sys/unix/unixres.c
@@ -0,0 +1,209 @@
+/*	SCCS Id: @(#)unixres.c	3.3	01/07/08	*/
+/* Copyright (c) Slash'EM development team, 2001. */
+/* NetHack may be freely redistributed.  See license for details. */
+
+/* [ALI] This module defines nh_xxx functions to replace getuid etc which
+ * will hide privileges from the caller if so desired.
+ *
+ * Currently supported UNIX variants:
+ *	Linux version 2.1.44 and above
+ *	FreeBSD (versions unknown)
+ *
+ * Note: SunOS and Solaris have no mechanism for retrieving the saved id,
+ * so temporarily dropping privileges on these systems is sufficient to
+ * hide them.
+ */
+
+#include "config.h"
+
+#ifdef GETRES_SUPPORT
+
+#if defined(LINUX)
+
+static _syscall3(int, getresuid, unsigned short *, ruid, \
+  unsigned short *, euid, unsigned short *, suid)
+static _syscall3(int, getresgid, unsigned short *, rgid, \
+  unsigned short *, egid, unsigned short *, sgid)
+
+static int
+real_getresuid(ruid, euid, suid)
+uid_t *ruid, *euid, *suid;
+{
+    int retval;
+    unsigned short r, e, s;
+    retval = getresuid(&r, &e, &s);
+    if (!retval) {
+	*ruid = r;
+	*euid = e;
+	*suid = s;
+    }
+    return retval;
+}
+
+static int
+real_getresgid(rgid, egid, sgid)
+gid_t *rgid, *egid, *sgid;
+{
+    int retval;
+    unsigned short r, e, s;
+    retval = getresgid(&r, &e, &s);
+    if (!retval) {
+	*rgid = r;
+	*egid = e;
+	*sgid = s;
+    }
+    return retval;
+}
+
+#elif defined(BSD) || defined(SVR4)
+
+#ifdef SYS_getresuid
+
+static int
+real_getresuid(ruid, euid, suid)
+uid_t *ruid, *euid, *suid;
+{
+    return syscall(SYS_getresuid, ruid, euid, suid);
+}
+
+#else	/* SYS_getresuid */
+
+static int
+real_getresuid(ruid, euid, suid)
+uid_t *ruid, *euid, *suid;
+{
+    int retval;
+    int pfd[2];
+    struct stat st;
+    if (pipe(pfd))
+	return -1;
+    retval = fstat(pfd[0], &st);
+    close(pfd[0]);
+    close(pfd[1]);
+    if (!retval) {
+	*euid = st.st_uid;
+	*ruid = syscall(SYS_getuid);
+	*suid = *ruid;			/* Not supported under SVR4 */
+    }
+    return retval;
+}
+
+#endif	/* SYS_getresuid */
+
+#ifdef SYS_getresgid
+
+static int
+real_getresgid(rgid, egid, sgid)
+gid_t *rgid, *egid, *sgid;
+{
+    return syscall(SYS_getresgid, rgid, egid, sgid);
+}
+
+#else	/* SYS_getresgid */
+
+static int
+real_getresgid(rgid, egid, sgid)
+gid_t *rgid, *egid, *sgid;
+{
+    int retval;
+    int pfd[2];
+    struct stat st;
+    if (pipe(pfd))
+	return -1;
+    retval = fstat(pfd[0], &st);
+    close(pfd[0]);
+    close(pfd[1]);
+    if (!retval) {
+	*egid = st.st_gid;
+	*rgid = syscall(SYS_getgid);
+	*sgid = *rgid;			/* Not supported under SVR4 */
+    }
+    return retval;
+}
+
+#endif	/* SYS_getresgid */
+#endif	/* LINUX || BSD || SVR4 */
+
+static unsigned int hiding_privileges = 0;
+
+/*
+ * Note: returns the value _after_ action.
+ */
+
+int
+hide_privileges(flag)
+boolean flag;
+{
+    if (flag)
+	hiding_privileges++;
+    else if (hiding_privileges)
+	hiding_privileges--;
+    return hiding_privileges;
+}
+
+int
+nh_getresuid(ruid, euid, suid)
+uid_t *ruid, *euid, *suid;
+{
+    int retval = real_getresuid(ruid, euid, suid);
+    if (!retval && hiding_privileges)
+	*euid = *suid = *ruid;
+    return retval;
+}
+
+uid_t
+nh_getuid()
+{
+    uid_t ruid, euid, suid;
+    (void) real_getresuid(&ruid, &euid, &suid);
+    return ruid;
+}
+
+uid_t
+nh_geteuid()
+{
+    uid_t ruid, euid, suid;
+    (void) real_getresuid(&ruid, &euid, &suid);
+    if (hiding_privileges)
+	euid = ruid;
+    return euid;
+}
+
+int
+nh_getresgid(rgid, egid, sgid)
+gid_t *rgid, *egid, *sgid;
+{
+    int retval = real_getresgid(rgid, egid, sgid);
+    if (!retval && hiding_privileges)
+	*egid = *sgid = *rgid;
+    return retval;
+}
+
+gid_t
+nh_getgid()
+{
+    gid_t rgid, egid, sgid;
+    (void) real_getresgid(&rgid, &egid, &sgid);
+    return rgid;
+}
+
+gid_t
+nh_getegid()
+{
+    gid_t rgid, egid, sgid;
+    (void) real_getresgid(&rgid, &egid, &sgid);
+    if (hiding_privileges)
+	egid = rgid;
+    return egid;
+}
+
+#else	/* GETRES_SUPPORT */
+
+int
+hide_privileges(flag)
+boolean flag;
+{
+    return 0;
+}
+
+#endif	/* GETRES_SUPPORT */