Signed-off-by: Karel Zak <kzak@xxxxxxxxxx>
---
include/pathnames.h | 1 +
login-utils/login.c | 122 +++++++++++++++++++++++++++++++++++++-------------
2 files changed, 91 insertions(+), 32 deletions(-)
diff --git a/include/pathnames.h b/include/pathnames.h
index 025e4af..1a54a03 100644
--- a/include/pathnames.h
+++ b/include/pathnames.h
@@ -29,6 +29,7 @@
#define _PATH_WTMPLOCK "/etc/wtmplock"
#define _PATH_HUSHLOGIN ".hushlogin"
+#define _PATH_HUSHLOGINS "/etc/hushlogins"
#ifndef _PATH_MAILDIR
#define _PATH_MAILDIR "/var/spool/mail"
diff --git a/login-utils/login.c b/login-utils/login.c
index 1adf330..7f6048c 100644
--- a/login-utils/login.c
+++ b/login-utils/login.c
@@ -566,7 +566,7 @@ static int loginpam_err(pam_handle_t * pamh, int retcode)
* The open(2) seems as the surest solution.
* -- kzak@xxxxxxxxxx (10-Apr-2009)
*/
-int effective_access(const char *path, int mode)
+static int effective_access(const char *path, int mode)
{
int fd = open(path, mode);
if (fd != -1)
@@ -574,6 +574,94 @@ int effective_access(const char *path, int mode)
return fd == -1 ? -1 : 0;
}
+/*
+ * Check per accout or global hush-login setting.
+ *
+ * Hushed mode is enabled:
+ *
+ * a) if global (e.g. /etc/hushlogins) hush file exists:
+ * 1) for ALL ACCOUNTS if the file is empty
+ * 2) for the current user if the username or shell are found in the file
+ *
+ * b) if ~/.hushlogin file exists
+ *
+ * The ~/.hushlogin is ignored if the global hush file exists.
+ *
+ * Note that shadow-utils login(1) does not support "a1)". The "a1)" is
+ * necessary if you want to use PAM for "Last login" message.
+ *
+ * -- Karel Zak <kzak@xxxxxxxxxx> (26-Aug-2011)
+ *
+ *
+ * Per-account check requires some explanation: As root we may not be able to
+ * read the directory of the user if it is on an NFS mounted filesystem. We
+ * temporarily set our effective uid to the user-uid making sure that we keep
+ * root privs. in the real uid.
+ *
+ * A portable solution would require a fork(), but we rely on Linux having the
+ * BSD setreuid()
+ */
+static int get_hushlogin_status(struct passwd *pwd)
+{
+ const char *files[] = { _PATH_HUSHLOGINS, _PATH_HUSHLOGIN, NULL };
+ char buf[BUFSIZ];
+ int i;
+
+ for (i = 0; files[i]; i++) {
+ const char *file = files[i];
+ int ok = 0;
+
+ /* Global hush-file*/
+ if (*file == '/') {
+ struct stat st;
+ FILE *f;
+
+ if (stat(file, &st) != 0)
+ continue; /* file does not exist */
+
+ if (st.st_size == 0)
+ return 1; /* for all accounts */
+
+ f = fopen(file, "r");
+ if (!f)
+ continue; /* ignore errors... */
+
+ while (ok == 0 && fgets(buf, sizeof(buf), f)) {
+ buf[strlen(buf) - 1] = '\0';
+ ok = !strcmp(buf, *buf == '/' ? pwd->pw_shell :
+ pwd->pw_name);
+ }
+ fclose(f);
+ if (ok)
+ return 1; /* found username/shell */
+
+ return 0; /* ignore per-account files */
+ }
+
+ /* Per-account setting */
+ if (strlen(pwd->pw_dir) + sizeof(file) + 2 > sizeof(buf))
+ continue;
+ else {
+ uid_t ruid = getuid();
+ gid_t egid = getegid();
+
+ sprintf(buf, "%s/%s", pwd->pw_dir, file);
+ setregid(-1, pwd->pw_gid);
+ setreuid(0, pwd->pw_uid);
+ ok = effective_access(buf, O_RDONLY) == 0;
+ setuid(0); /* setreuid doesn't do it alone! */
+ setreuid(ruid, 0);
+ setregid(-1, egid);
+
+ if (ok)
+ return 1; /* enabled by user */
+ }
+ }
+
+ return 0;
+}
+
+
int main(int argc, char **argv)
{
extern int optind;
@@ -879,37 +967,7 @@ int main(int argc, char **argv)
endpwent();
- {
- /*
- * Check per accout setting.
- *
- * This requires some explanation: As root we may not be able to
- * read the directory of the user if it is on an NFS mounted
- * filesystem. We temporarily set our effective uid to the user-uid
- * making sure that we keep root privs. in the real uid.
- *
- * A portable solution would require a fork(), but we rely on Linux
- * having the BSD setreuid()
- */
- char tmpstr[PATH_MAX];
- uid_t ruid = getuid();
- gid_t egid = getegid();
-
- /* avoid snprintf - old systems do not have it, or worse,
- have a libc in which snprintf is the same as sprintf */
- if (strlen(pwd->pw_dir) + sizeof(_PATH_HUSHLOGIN) + 2 >
- PATH_MAX)
- cxt.quiet = 0;
- else {
- sprintf(tmpstr, "%s/%s", pwd->pw_dir, _PATH_HUSHLOGIN);
- setregid(-1, pwd->pw_gid);
- setreuid(0, pwd->pw_uid);
- cxt.quiet = (effective_access(tmpstr, O_RDONLY) == 0);
- setuid(0); /* setreuid doesn't do it alone! */
- setreuid(ruid, 0);
- setregid(-1, egid);
- }
- }
+ cxt.quiet = get_hushlogin_status(pwd);
log_utmp(&cxt);
log_audit(&cxt, 1);
--
1.7.6.4
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