Changeset ed8c513 in rtems

Timestamp:

10/02/02 17:33:17 (21 years ago)

Author:

Joel Sherrill <joel.sherrill@…>

Branches:

4.10, 4.11, 4.8, 4.9, 5, master

Children:

bcac0cb

Parents:

f4ceef3e

Message:

2002-10-02 Eric Norum <eric.norum@…>

• src/getpwent.c: Per PR283, reimplement to address reentrancy problems.
• src/getgrent.c: Removed as functionality is now just a wrapper for common routines in src/getpwent.c.
• Makefile.am: Reflect file removal.

Location:

cpukit/libcsupport

Files:

• ChangeLog (modified) (1 diff)
• Makefile.am (modified) (1 diff)
• src/getgrent.c (deleted)
• src/getpwent.c (modified) (5 diffs)

cpukit/libcsupport/ChangeLog

@@ +1 @@
+2002-10-02      Eric Norum <eric.norum@usask.ca>
+
+        * src/getpwent.c: Per PR283, reimplement to address reentrancy problems.
+        * src/getgrent.c: Removed as functionality is now just a wrapper for 
+        common routines in src/getpwent.c.
+        * Makefile.am: Reflect file removal.
+
 2002-09-14      Joel Sherrill <joel@OARcorp.com>
 

cpukit/libcsupport/Makefile.am

@@ -118 +118 @@
 MALLOC_C_FILES = src/malloc.c src/mallocfreespace.c src/__brk.c src/__sbrk.c
 
-PASSWORD_GROUP_C_FILES = src/getpwent.c src/getgrent.c
+PASSWORD_GROUP_C_FILES = src/getpwent.c
 
 TERMINAL_IDENTIFICATION_C_FILES = src/ctermid.c src/isatty.c src/ttyname.c \

cpukit/libcsupport/src/getpwent.c

@@ -16 +16 @@
 #include <sys/types.h>
 #include <pwd.h>
+#include <grp.h>
 #include <errno.h>
 #include <unistd.h>
@@ -21 +22 @@
 #include <string.h>
 #include <limits.h>
-#include <fcntl.h>
-#include <unistd.h>
+#include <ctype.h>
 
 #include <rtems/libio_.h>
 
-static struct passwd pw_passwd;  /* password structure */
+/*
+ * Static, thread-unsafe, buffers
+ */
 static FILE *passwd_fp;
-
-/*
- *  The size of these buffers is arbitrary and there is no provision
- *  to protect any of them from overflowing.  The scanf patterns
- *  need to be changed to prevent overflowing.  In addition,
- *  the limits on these needs to be examined.
- */
-
-static char logname[8];
-static char password[1024];
-static char comment[1024];
-static char gecos[1024];
-static char dir[1024];
-static char shell[1024];
-
-/*
- *  Initialize a useable but dummy /etc/passwd
- *
- *  NOTE: Ignore all errors.
- *
- */
-
-static char etc_passwd_initted = 0;
-
+static char pwbuf[200];
+static struct passwd pwent;
+static FILE *group_fp;
+static char grbuf[200];
+static struct group grent;
+
+/*
+ * Initialize useable but dummy databases
+ */
 void init_etc_passwd_group(void)
 {
   FILE *fp;
-
-  if ( etc_passwd_initted )
+  static char etc_passwd_initted = 0;
+
+  if (etc_passwd_initted)
     return;
   etc_passwd_initted = 1;
-
-  (void) mkdir( "/etc", 0777);
+  mkdir("/etc", 0777);
 
   /*
    *  Initialize /etc/passwd
    */
-
-  if ((fp = fopen ("/etc/passwd", "w")) == NULL)
-    return;
-
-  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 );
+  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", "w")) == NULL)
-    return;
-
-  fprintf( fp, "root:x:0:root\n"
-               "rtems:x:1:rtems\n"
-               "tty:x:2:tty\n" );
-
-  fclose( fp );
+  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
+ */
+static int 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;
+  rtems_user_env_t * aux=rtems_current_user_env; /* save */
+
+  init_etc_passwd_group();
+  rtems_current_user_env=&rtems_global_user_env; /* set root */
+
+  if ((fp = fopen("/etc/passwd", "r")) == NULL) {
+    errno = EINVAL;
+    rtems_current_user_env=aux; /* restore */
+    return -1;
+  }
+  for(;;) {
+    if (!scanpw(fp, pwd, buffer, bufsize)) {
+      errno = EINVAL;
+      fclose(fp);
+      rtems_current_user_env=aux; /* restore */
+      return -1;
+    }
+    if (name) {
+      match = (strcmp(pwd->pw_name, name) == 0);
+    }
+    else {
+      match = (pwd->pw_uid == uid);
+    }
+    if (match) {
+      fclose(fp);
+      *result = pwd;
+      rtems_current_user_env=aux; /* restore */
+      return 0;
+    }
+  }
+  fclose(fp);
+  errno = EINVAL;
+  rtems_current_user_env=aux; /* restore */
+  return -1;
 }
 
@@ -97 +230 @@
 )
 {
-  FILE *fp;
+  return getpw_r(name, 0, pwd, buffer, bufsize, result);
+}
+
+struct passwd *getpwnam( 
+  const char *name
+)
+{
+  struct passwd *p;
+
+  if(getpwnam_r(name, &pwent, pwbuf, sizeof pwbuf, &p))
+    return NULL;
+  return p;
+}
+
+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);
+}
+
+struct passwd *getpwuid(
+  uid_t uid
+)
+{
+  struct passwd *p;
+
+  if(getpwuid_r(uid, &pwent, pwbuf, sizeof pwbuf, &p))
+    return NULL;
+  return p;
+}
+
+struct passwd *getpwent()
+{
+  if (passwd_fp == NULL)
+    return NULL;
+  if (!scanpw(passwd_fp, &pwent, pwbuf, sizeof pwbuf))
+    return NULL;
+  return &pwent;
+}
+
+void setpwent(void)
+{
   rtems_user_env_t * aux=rtems_current_user_env; /* save */
-
   init_etc_passwd_group();
   rtems_current_user_env=&rtems_global_user_env; /* set root */
 
-  if ((fp = fopen ("/etc/passwd", "r")) == NULL) {
+  if (passwd_fp != NULL)
+    fclose(passwd_fp);
+  passwd_fp = fopen("/etc/passwd", "r");
+  rtems_current_user_env=aux; /* restore */
+}
+
+void endpwent(void)
+{
+  if (passwd_fp != NULL)
+    fclose(passwd_fp);
+}
+
+/*
+ * Extract a single group record from the database
+ */
+static int 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 **)(((unsigned long)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;
+  rtems_user_env_t * aux=rtems_current_user_env; /* save */
+
+  init_etc_passwd_group();
+  rtems_current_user_env=&rtems_global_user_env; /* set root */
+
+  if ((fp = fopen("/etc/group", "r")) == NULL) {
     errno = EINVAL;
     rtems_current_user_env=aux; /* restore */
     return -1;
   }
-
-  while (fgets (buffer, bufsize, fp)) {
-    sscanf (buffer, "%[^:]:%[^:]:%d:%d:%[^:]:%[^:]:%[^:]:%s\n",
-        logname, password, &pwd->pw_uid,
-        &pwd->pw_gid, comment, gecos,
-        dir, shell);
-    pwd->pw_name = logname;
-    pwd->pw_passwd = password;
-    pwd->pw_comment = comment;
-    pwd->pw_gecos = gecos;
-    pwd->pw_dir = dir;
-    pwd->pw_shell = shell;
-
-    if (!strcmp (logname, name)) {
-      fclose (fp);
-      *result = pwd;
+  for(;;) {
+    if (!scangr(fp, grp, buffer, bufsize)) {
+      errno = EINVAL;
+      fclose(fp);
       rtems_current_user_env=aux; /* restore */
-      return 0;
-    }
-  }
-  fclose (fp);
-  errno = EINVAL;
-    rtems_current_user_env=aux; /* restore */
-  return -1;
-}
-
-struct passwd *getpwnam(
-  const char *name
-)
-{
-  char   buf[1024];
-  struct passwd *p;
-
-  if ( getpwnam_r( name, &pw_passwd, buf, 1024, &p ) )
-    return NULL;
-
-  return p;
-}
-
-int getpwuid_r(
-  uid_t           uid,
-  struct passwd  *pwd,
-  char           *buffer,
-  size_t          bufsize,
-  struct passwd **result
-)
-{
-  FILE *fp;
-  rtems_user_env_t * aux=rtems_current_user_env; /* save */
-
-  init_etc_passwd_group();
-  rtems_current_user_env=&rtems_global_user_env; /* set root */
-
-  if ((fp = fopen ("/etc/passwd", "r")) == NULL) {
-    errno = EINVAL;
-    rtems_current_user_env=aux; /* restore */
-    return -1;
-  }
-
-  while (fgets (buffer, bufsize, fp)) {
-    sscanf (buffer, "%[^:]:%[^:]:%d:%d:%[^:]:%[^:]:%[^:]:%s\n",
-     logname, password, &pw_passwd.pw_uid,
-     &pw_passwd.pw_gid, comment, gecos,
-     dir, shell);
-    pwd->pw_name = logname;
-    pwd->pw_passwd = password;
-    pwd->pw_comment = comment;
-    pwd->pw_gecos = gecos;
-    pwd->pw_dir = dir;
-    pwd->pw_shell = shell;
-
-    if (uid == pwd->pw_uid) {
-      fclose (fp);
-      *result = pwd;
+      return -1;
+    }
+    if (name) {
+      match = (strcmp(grp->gr_name, name) == 0);
+    }
+    else {
+      match = (grp->gr_gid == gid);
+    }
+    if (match) {
+      fclose(fp);
+      *result = grp;
       rtems_current_user_env=aux; /* restore */
       return 0;
     }
   }
-  fclose (fp);
+  fclose(fp);
   errno = EINVAL;
   rtems_current_user_env=aux; /* restore */
@@ -192 +390 @@
 }
 
-struct passwd *getpwuid(
-  uid_t uid
-)
-{
-  char   buf[1024];
-  struct passwd *p;
-
-  if ( getpwuid_r( uid, &pw_passwd, buf, 1024, &p ) )
-    return NULL;
-
+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);
+}
+
+struct group *getgrnam( 
+  const char *name
+)
+{
+  struct group *p;
+
+  if(getgrnam_r(name, &grent, grbuf, sizeof grbuf, &p))
+    return NULL;
   return p;
 }
 
-struct passwd *getpwent()
-{
-  char buf[1024];
-
-  if (passwd_fp == NULL)
-    return NULL;
-
-  if (fgets (buf, sizeof (buf), passwd_fp) == NULL)
-    return NULL;
-
-  sscanf (buf, "%[^:]:%[^:]:%d:%d:%[^:]:%[^:]:%[^:]:%s\n",
-    logname, password, &pw_passwd.pw_uid,
-    &pw_passwd.pw_gid, comment, gecos,
-    dir, shell);
-  pw_passwd.pw_name = logname;
-  pw_passwd.pw_passwd = password;
-  pw_passwd.pw_comment = comment;
-  pw_passwd.pw_gecos = gecos;
-  pw_passwd.pw_dir = dir;
-  pw_passwd.pw_shell = shell;
-
-  return &pw_passwd;
-}
-
-void setpwent( void )
+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);
+}
+
+struct group *getgrgid(
+  gid_t gid
+)
+{
+  struct group *p;
+
+  if(getgrgid_r(gid, &grent, grbuf, sizeof grbuf, &p))
+    return NULL;
+  return p;
+}
+
+struct group *getgrent()
+{
+  if (group_fp == NULL)
+    return NULL;
+  if (!scangr(group_fp, &grent, grbuf, sizeof grbuf))
+    return NULL;
+  return &grent;
+}
+
+void setgrent(void)
 {
   rtems_user_env_t * aux=rtems_current_user_env; /* save */
@@ -235 +449 @@
   rtems_current_user_env=&rtems_global_user_env; /* set root */
 
-  if (passwd_fp != NULL)
-    fclose (passwd_fp);
-
-  passwd_fp = fopen ("/etc/passwd", "r");
+  if (group_fp != NULL)
+    fclose(group_fp);
+  group_fp = fopen("/etc/group", "r");
   rtems_current_user_env=aux; /* restore */
 }
 
-void endpwent( void )
-{
-  if (passwd_fp != NULL)
-    fclose (passwd_fp);
-}
+void endgrent(void)
+{
+  if (group_fp != NULL)
+    fclose(group_fp);
+}