/* vi: set sw=4 ts=4: */ /* * __getgrent.c - This file is part of the libc-8086/grp package for ELKS, * Copyright (C) 1995, 1996 Nat Friedman <ndf@linux.mit.edu>. * Copyright (C) 2001-2003 Erik Andersen <andersee@debian.org> * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the Free * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * */ #include <features.h> #include <unistd.h> #include <stdlib.h> #include <string.h> #include <errno.h> #include "config.h" /* * This is the core group-file read function. It behaves exactly like * getgrent() except that it is passed a file descriptor. getgrent() * is just a wrapper for this function. */ int __getgrent_r (struct group *__restrict group, char *__restrict line_buff, size_t buflen, int grp_fd) { char *endptr, *field_begin, **members; int i, line_len, member_num = 0; if (buflen<GRP_BUFFER_SIZE) { return ERANGE; } /* We use the restart label to handle malformatted lines */ restart: /* Read the group line into the buffer for processing */ if ((line_len = read(grp_fd, line_buff, buflen)) <= 0) { return EIO; } field_begin = strchr(line_buff, '\n'); if (field_begin != NULL) lseek(grp_fd, (long) (1 + field_begin - (line_buff + line_len)), SEEK_CUR); else { /* The line is too long - skip it. :-\ */ do { if ((line_len = read(grp_fd, line_buff, buflen)) <= 0) { return EIO; } } while (!(field_begin = strchr(line_buff, '\n'))); lseek(grp_fd, (long) (field_begin - line_buff) - line_len + 1, SEEK_CUR); goto restart; } if (*line_buff == '#' || *line_buff == ' ' || *line_buff == '\n' || *line_buff == '\t') goto restart; *field_begin = '\0'; /* We've read the line; now parse it. */ field_begin = line_buff; for (i = 0; i < 3; i++) { switch (i) { case 0: group->gr_name = field_begin; break; case 1: group->gr_passwd = field_begin; break; case 2: group->gr_gid = (__gid_t) strtoul(field_begin, &endptr, 10); if (*endptr != ':') goto restart; break; } if (i < 3) { field_begin = strchr(field_begin, ':'); if (field_begin == NULL) break; *field_begin++ = '\0'; } } members = (char **) malloc(sizeof(char *)); if (members==NULL) { return ENOMEM; } while(field_begin && strlen(field_begin)) { members[member_num++] = field_begin; members = (char **) realloc(members, (member_num + 1) * sizeof(char *)); if (members==NULL) { return ENOMEM; } endptr = strchr(field_begin, ','); if (endptr == NULL) { /* Final entry */ break; } *field_begin++ = '\0'; } members[member_num] = NULL; group->gr_mem = members; return 0; }