libcsupport: Split passwd/group support

1 files changed, 346 insertions, 0 deletions

diff --git a/cpukit/libcsupport/src/pwdgrp.c b/cpukit/libcsupport/src/pwdgrp.c
new file mode 100644
index 0000000000..d8e1947b3f
--- /dev/null
+++ b/cpukit/libcsupport/src/pwdgrp.c
@@ -0,0 +1,346 @@
+/**
+ *  @file
+ *
+ *  @brief User Database Access Routines
+ *  @ingroup libcsupport
+ */
+
+/*
+ *  Copyright (c) 1999-2009 Ralf Corsepius <corsepiu@faw.uni-ulm.de>
+ *  Copyright (c) 1999-2013 Joel Sherrill <joel.sherrill@OARcorp.com>
+ *  Copyright (c) 2000-2001 Fernando Ruiz Casas <fernando.ruiz@ctv.es>
+ *  Copyright (c) 2002 Eric Norum <eric.norum@usask.ca>
+ *  Copyright (c) 2003 Till Straumann <strauman@slac.stanford.edu>
+ *  Copyright (c) 2012 Alex Ivanov <alexivanov97@gmail.com>
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.rtems.org/license/LICENSE.
+ */
+
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <sys/stat.h>
+#include <pwd.h>
+#include <grp.h>
+#include <errno.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <limits.h>
+#include <ctype.h>
+
+#include <rtems/seterr.h>
+
+#include "pwdgrp.h"
+
+/**
+ *  Initialize useable but dummy databases
+ */
+void _libcsupport_pwdgrp_init(void)
+{
+  FILE *fp;
+  static char etc_passwd_initted = 0;
+
+  if (etc_passwd_initted)
+    return;
+  etc_passwd_initted = 1;
+  mkdir("/etc", 0777);
+
+  /*
+   *  Initialize /etc/passwd
+   */
+  if ((fp = fopen("/etc/passwd", "r")) != NULL) {
+    fclose(fp);
+  }
+  else if ((fp = fopen("/etc/passwd", "w")) != NULL) {
+    fprintf(fp, "root:*:0:0:root::/:/bin/sh\n"
+                 "rtems:*:1:1:RTEMS Application::/:/bin/sh\n"
+                 "tty:!:2:2:tty owner::/:/bin/false\n" );
+    fclose(fp);
+  }
+
+  /*
+   *  Initialize /etc/group
+   */
+  if ((fp = fopen("/etc/group", "r")) != NULL) {
+    fclose(fp);
+  }
+  else if ((fp = fopen("/etc/group", "w")) != NULL) {
+    fprintf( fp, "root:x:0:root\n"
+                 "rtems:x:1:rtems\n"
+                 "tty:x:2:tty\n" );
+    fclose(fp);
+  }
+}
+
+/**
+ *  Extract a string value from the database
+ */
+static int
+scanString(FILE *fp, char **name, char **bufp, size_t *nleft, int nlFlag)
+{
+  int c;
+
+  *name = *bufp;
+  for (;;) {
+    c = getc(fp);
+    if (c == ':') {
+        if (nlFlag)
+            return 0;
+        break;
+    }
+    if (c == '\n') {
+        if (!nlFlag)
+            return 0;
+        break;
+    }
+    if (c == EOF)
+      return 0;
+    if (*nleft < 2)
+      return 0;
+    **bufp = c;
+    ++(*bufp);
+    --(*nleft);
+  }
+  **bufp = '\0';
+  ++(*bufp);
+  --(*nleft);
+  return 1;
+}
+
+/**
+ *  Extract an integer value from the database
+ */
+static int
+scanInt(FILE *fp, int *val)
+{
+  int c;
+  unsigned int i = 0;
+  unsigned int limit = INT_MAX;
+  int sign = 0;
+  int d;
+
+  for (;;) {
+    c = getc(fp);
+    if (c == ':')
+      break;
+    if (sign == 0) {
+      if (c == '-') {
+        sign = -1;
+        limit++;
+        continue;
+      }
+      sign = 1;
+    }
+    if (!isdigit(c))
+      return 0;
+    d = c - '0';
+    if ((i > (limit / 10))
+     || ((i == (limit / 10)) && (d > (limit % 10))))
+      return 0;
+    i = i * 10 + d;
+  }
+  if (sign == 0)
+    return 0;
+  *val = i * sign;
+  return 1;
+}
+
+/*
+ * Extract a single password record from the database
+ */
+int _libcsupport_scanpw(
+  FILE *fp,
+  struct passwd *pwd,
+  char *buffer,
+  size_t bufsize
+)
+{
+  int pwuid, pwgid;
+
+  if (!scanString(fp, &pwd->pw_name, &buffer, &bufsize, 0)
+   || !scanString(fp, &pwd->pw_passwd, &buffer, &bufsize, 0)
+   || !scanInt(fp, &pwuid)
+   || !scanInt(fp, &pwgid)
+   || !scanString(fp, &pwd->pw_comment, &buffer, &bufsize, 0)
+   || !scanString(fp, &pwd->pw_gecos, &buffer, &bufsize, 0)
+   || !scanString(fp, &pwd->pw_dir, &buffer, &bufsize, 0)
+   || !scanString(fp, &pwd->pw_shell, &buffer, &bufsize, 1))
+    return 0;
+  pwd->pw_uid = pwuid;
+  pwd->pw_gid = pwgid;
+  return 1;
+}
+
+static int getpw_r(
+  const char     *name,
+  int             uid,
+  struct passwd  *pwd,
+  char           *buffer,
+  size_t          bufsize,
+  struct passwd **result
+)
+{
+  FILE *fp;
+  int match;
+
+  _libcsupport_pwdgrp_init();
+
+  if ((fp = fopen("/etc/passwd", "r")) == NULL)
+    rtems_set_errno_and_return_minus_one( EINVAL );
+
+  for(;;) {
+    if (!_libcsupport_scanpw(fp, pwd, buffer, bufsize))
+      goto error_einval;
+
+    if (name) {
+      match = (strcmp(pwd->pw_name, name) == 0);
+    } else {
+      match = (pwd->pw_uid == uid);
+    }
+
+    if (match) {
+      fclose(fp);
+      *result = pwd;
+      return 0;
+    }
+  }
+error_einval:
+  fclose(fp);
+  rtems_set_errno_and_return_minus_one( EINVAL );
+}
+
+int getpwnam_r(
+  const char     *name,
+  struct passwd  *pwd,
+  char           *buffer,
+  size_t          bufsize,
+  struct passwd **result
+)
+{
+  return getpw_r(name, 0, pwd, buffer, bufsize, result);
+}
+
+int getpwuid_r(
+  uid_t           uid,
+  struct passwd  *pwd,
+  char           *buffer,
+  size_t          bufsize,
+  struct passwd **result
+)
+{
+  return getpw_r(NULL, uid, pwd, buffer, bufsize, result);
+}
+
+/**
+ *  Extract a single group record from the database
+ */
+int _libcsupport_scangr(
+  FILE *fp,
+  struct group *grp,
+  char *buffer,
+  size_t bufsize
+)
+{
+  int grgid;
+  char *grmem, *cp;
+  int memcount;
+
+  if (!scanString(fp, &grp->gr_name, &buffer, &bufsize, 0)
+   || !scanString(fp, &grp->gr_passwd, &buffer, &bufsize, 0)
+   || !scanInt(fp, &grgid)
+   || !scanString(fp, &grmem, &buffer, &bufsize, 1))
+    return 0;
+  grp->gr_gid = grgid;
+
+  /*
+   * Determine number of members
+   */
+  for (cp = grmem, memcount = 1 ; *cp != 0 ; cp++) {
+    if(*cp == ',')
+      memcount++;
+  }
+
+  /*
+   * Hack to produce (hopefully) a suitably-aligned array of pointers
+   */
+  if (bufsize < (((memcount+1)*sizeof(char *)) + 15))
+    return 0;
+  grp->gr_mem = (char **)(((uintptr_t)buffer + 15) & ~15);
+
+  /*
+   * Fill in pointer array
+   */
+  grp->gr_mem[0] = grmem;
+  for (cp = grmem, memcount = 1 ; *cp != 0 ; cp++) {
+    if(*cp == ',') {
+      *cp = '\0';
+      grp->gr_mem[memcount++] = cp + 1;
+    }
+  }
+  grp->gr_mem[memcount] = NULL;
+  return 1;
+}
+
+static int getgr_r(
+  const char     *name,
+  int             gid,
+  struct group   *grp,
+  char           *buffer,
+  size_t          bufsize,
+  struct group  **result
+)
+{
+  FILE *fp;
+  int match;
+
+  _libcsupport_pwdgrp_init();
+
+  if ((fp = fopen("/etc/group", "r")) == NULL)
+    rtems_set_errno_and_return_minus_one( EINVAL );
+
+  for(;;) {
+    if (!_libcsupport_scangr(fp, grp, buffer, bufsize))
+      goto error_einval;
+
+    if (name) {
+      match = (strcmp(grp->gr_name, name) == 0);
+    } else {
+      match = (grp->gr_gid == gid);
+    }
+
+    if (match) {
+      fclose(fp);
+      *result = grp;
+      return 0;
+    }
+  }
+error_einval:
+  fclose(fp);
+  rtems_set_errno_and_return_minus_one( EINVAL );
+}
+
+int getgrnam_r(
+  const char     *name,
+  struct group   *grp,
+  char           *buffer,
+  size_t          bufsize,
+  struct group  **result
+)
+{
+  return getgr_r(name, 0, grp, buffer, bufsize, result);
+}
+
+int getgrgid_r(
+  gid_t           gid,
+  struct group   *grp,
+  char           *buffer,
+  size_t          bufsize,
+  struct group  **result
+)
+{
+  return getgr_r(NULL, gid, grp, buffer, bufsize, result);
+}