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Diffstat (limited to 'lib/sgetpwent.c')
| -rw-r--r-- | lib/sgetpwent.c | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/lib/sgetpwent.c b/lib/sgetpwent.c new file mode 100644 index 0000000..293aabe --- /dev/null +++ b/lib/sgetpwent.c @@ -0,0 +1,122 @@ +/* + * Copyright (c) 1989 - 1994, Julianne Frances Haugh + * Copyright (c) 1996 - 1998, Marek Michałkiewicz + * Copyright (c) 2003 - 2005, Tomasz Kłoczko + * Copyright (c) 2008 , Nicolas François + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. The name of the copyright holders or contributors may not be used to + * endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A + * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include <config.h> + +#ident "$Id$" + +#include <sys/types.h> +#include "defines.h" +#include <stdio.h> +#include <pwd.h> +#include "prototypes.h" + +#define NFIELDS 7 + +/* + * sgetpwent - convert a string to a (struct passwd) + * + * sgetpwent() parses a string into the parts required for a password + * structure. Strict checking is made for the UID and GID fields and + * presence of the correct number of colons. Any failing tests result + * in a NULL pointer being returned. + * + * NOTE: This function uses hard-coded string scanning functions for + * performance reasons. I am going to come up with some conditional + * compilation glarp to improve on this in the future. + */ +struct passwd *sgetpwent (const char *buf) +{ + static struct passwd pwent; + static char pwdbuf[1024]; + register int i; + register char *cp; + char *fields[NFIELDS]; + + /* + * Copy the string to a static buffer so the pointers into + * the password structure remain valid. + */ + + if (strlen (buf) >= sizeof pwdbuf) + return 0; /* fail if too long */ + strcpy (pwdbuf, buf); + + /* + * Save a pointer to the start of each colon separated + * field. The fields are converted into NUL terminated strings. + */ + + for (cp = pwdbuf, i = 0; (i < NFIELDS) && (NULL != cp); i++) { + fields[i] = cp; + while (('\0' != *cp) && (':' != *cp)) { + cp++; + } + + if ('\0' != *cp) { + *cp = '\0'; + cp++; + } else { + cp = NULL; + } + } + + /* + * There must be exactly NFIELDS colon separated fields or + * the entry is invalid. Also, the UID and GID must be non-blank. + */ + + if (i != NFIELDS || *fields[2] == '\0' || *fields[3] == '\0') + return NULL; + + /* + * Each of the fields is converted the appropriate data type + * and the result assigned to the password structure. If the + * UID or GID does not convert to an integer value, a NULL + * pointer is returned. + */ + + pwent.pw_name = fields[0]; + pwent.pw_passwd = fields[1]; + if (get_uid (fields[2], &pwent.pw_uid) == 0) { + return NULL; + } + if (get_gid (fields[3], &pwent.pw_gid) == 0) { + return NULL; + } + pwent.pw_gecos = fields[4]; + pwent.pw_dir = fields[5]; + pwent.pw_shell = fields[6]; + + return &pwent; +} + |