config_files.c

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#include "config.h"
#include "config_files.h"

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <pwd.h>
#include <fcntl.h>
#include <errno.h>
#include <unistd.h>
#include <envz.h>

#include "check_path_exists.h"
#include "len.h"

#define ROUNDUP(a, b) (((a) & ~((b)-1)) + (b))

int add_config_file(char **list, size_t *list_len, size_t *list_size, unsigned char id, char *file, size_t file_len, unsigned int check_path)
{
        static char *home_dir = NULL;
        static size_t home_dir_len = 0;
        char *ptr;

        if(home_dir == NULL)
        {
                struct passwd *pw = NULL;

                /* search for the users home dir.
                 * First lookup the enviroment variable HOME,
                 * if this is not set lookup the directory in the userdatabse
                 * if there is still no match and uid is 0, try /root
                 * and finaly fail.
                 */
                if(getenv("HOME") != NULL)
                      home_dir = strdup(getenv("HOME"));
                else if((pw = getpwuid(getuid())) == NULL)
                {
                        if(pw->pw_dir != NULL)
                                home_dir = strdup(pw->pw_dir);
                        else if(pw->pw_dir == NULL && pw->pw_uid == 0 && check_dir_exists("/root", PATH_R | PATH_W) == 0)
                                home_dir = strdup("/root");
                }

                /* check if the home directory exists, if not fail */
                if(home_dir == NULL || check_dir_exists(home_dir, PATH_W) != 0)
                {
                        errno = ENOENT;
                        return -1;
                }
                home_dir_len = str_len(home_dir);
        }

        if(*list == NULL || *list_size < *list_len + home_dir_len + 1 + file_len + 3)
        {
                if(*list == NULL) *list_len = 0;
                *list_size = ROUNDUP(*list_len + home_dir_len + 1 + file_len + 3, 32);
                ptr = (char *)realloc(*list, *list_size);
                if(ptr == NULL)
                {
                  errno = ENOMEM;
                  return -1;
                }
                *list = ptr;
        }

        (*list)[(*list_len)++] = id;
        (*list)[(*list_len)++] = '=';
        ptr = *list + *list_len;
        strncpy(*list + *list_len, home_dir, home_dir_len);
        *list_len += home_dir_len;
        if(file[0] == '/' && home_dir[home_dir_len - 1] == '/')
        {
                file++;
                file_len--;
        }
        else if(file[0] != '/' && home_dir[home_dir_len - 1] != '/')
                (*list)[(*list_len)++] = '/';

        strncpy(*list + *list_len, file, file_len);
        *list_len += file_len;
        (*list)[(*list_len)++] = '\0';

        if((check_path & S_IFMT) > 0)
        {
                if(check_path_exists(ptr, check_path & S_IFMT, check_path & (PATH_R | PATH_W | PATH_X)) == 0)
                        return 0;
                else if((check_path & CREATE_PATH) == CREATE_PATH)
                { /* requested path does not exists, try to create it */
                        if(S_ISDIR(check_path & S_IFMT))
                                return mkdir(ptr, S_IRUSR | S_IWUSR | S_IXUSR | S_IRGRP | S_IXGRP);
                        else if(S_ISREG(check_path & S_IFMT))
                        {
                                int fd = open(ptr, O_CREAT, S_IRUSR | S_IWUSR | S_IRGRP);
                                if(fd == -1)
                                        return -1;
                                close(fd);
                                return 0;
                        }
                        errno = ENOENT;
                        return -1;
                }
                else
                { /* path does not exists and CREATE_PATH is not specified */
                        errno = ENOENT;
                        return -1;
                }
        }
        return 0;
}

char *get_config_file(char *list, size_t list_size, unsigned char id)
{
        char s[2];
        s[0] = id;
        s[1] = '\0';
        return envz_get(list, list_size, s);
}