files.c

/*

   honggfuzz - file operations
   -----------------------------------------

   Author: Robert Swiecki <swiecki@google.com>

   Copyright 2010 by Google Inc. All Rights Reserved.

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

     http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.

*/

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <unistd.h>
#include <stdlib.h>
#include <fcntl.h>
#include <dirent.h>
#include <string.h>
#include <stdio.h>
#include <errno.h>
#include <stdint.h>

#include "common.h"
#include "files.h"
#include "log.h"

bool files_writeToFd(int fd, uint8_t * buf, off_t fileSz)
{
    off_t written = 0;
    while (written < fileSz) {
        ssize_t sz = write(fd, &buf[written], fileSz - written);
        if (sz < 0 && errno == EINTR)
            continue;

        if (sz < 0)
            return false;

        written += sz;
    }

    return true;
}

bool files_writePatternToFd(int fd, off_t size, unsigned char p)
{
    void *buf = malloc(size);
    if (!buf) {
        LOGMSG_P(l_WARN, "Couldn't allocate memory");
        return false;
    }

    memset(buf, p, (size_t) size);
    int ret = files_writeToFd(fd, buf, size);
    free(buf);

    return ret;
}

uint8_t *files_mapFileToRead(char *fileName, off_t * fileSz, int *fd)
{
    if ((*fd = open(fileName, O_RDONLY)) == -1) {
        LOGMSG_P(l_WARN, "Couldn't open() '%s' file in R/O mode", fileName);
        return NULL;
    }

    struct stat st;
    if (fstat(*fd, &st) == -1) {
        LOGMSG_P(l_WARN, "Couldn't stat() the '%s' file", fileName);
        close(*fd);
        return NULL;
    }

    uint8_t *buf;
    if ((buf = mmap(NULL, st.st_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, *fd, 0)) == MAP_FAILED) {
        LOGMSG_P(l_WARN, "Couldn't mmap() the '%s' file", fileName);
        close(*fd);
        return NULL;
    }

    *fileSz = st.st_size;
    return buf;
}

static bool files_readdir(honggfuzz_t * hfuzz)
{
    DIR *dir = opendir(hfuzz->inputFile);
    if (!dir) {
        LOGMSG_P(l_ERROR, "Couldn't open dir '%s'", hfuzz->inputFile);
        return false;
    }

    int count = 0;

    for (;;) {
        struct dirent de, *res;
        if (readdir_r(dir, &de, &res) > 0) {
            LOGMSG_P(l_ERROR, "Couldn't read the '%s' dir", hfuzz->inputFile);
            closedir(dir);
            return false;
        }

        if (res == NULL && count > 0) {
            LOGMSG(l_INFO, "%d input files have been added to the list", hfuzz->fileCnt);
            closedir(dir);
            return true;
        }

        if (res == NULL && count == 0) {
            LOGMSG(l_ERROR, "Directory '%s' doesn't contain any regular files", hfuzz->inputFile);
            closedir(dir);
            return false;
        }

        char path[PATH_MAX];
        snprintf(path, sizeof(path), "%s/%s", hfuzz->inputFile, res->d_name);

        struct stat st;
        if (stat(path, &st) == -1) {
            LOGMSG(l_WARN, "Couldn't stat() the '%s' file", path);
            continue;
        }

        if (!S_ISREG(st.st_mode)) {
            LOGMSG(l_DEBUG, "'%s' is not a regular file, skipping", path);
            continue;
        }

        if (st.st_size == 0) {
            LOGMSG(l_DEBUG, "'%s' is empty", path);
            continue;
        }

        if (!(hfuzz->files = realloc(hfuzz->files, sizeof(char *) * (count + 1)))) {
            LOGMSG_P(l_ERROR, "Couldn't allocate memory");
            closedir(dir);
            return false;
        }

        hfuzz->files[count] = strdup(path);
        if (!hfuzz->files[count]) {
            LOGMSG_P(l_ERROR, "Couldn't allocate memory");
            closedir(dir);
            return false;
        }
        hfuzz->fileCnt = ++count;

        LOGMSG(l_DEBUG, "Added '%s' to the list of input files", path);
    }

    abort();                    /* NOTREACHED */
    return false;
}

bool files_init(honggfuzz_t * hfuzz)
{
    if (hfuzz->externalCommand && !hfuzz->inputFile) {
        LOGMSG(l_INFO,
               "No input file corpus specified, the external command '%s' is responsible for creating the fuzz files",
               hfuzz->externalCommand);
        return true;
    }

    hfuzz->files = malloc(sizeof(char *));
    if (!hfuzz->files) {
        LOGMSG_P(l_ERROR, "Couldn't allocate memory");
        return false;
    }

    if (!hfuzz->inputFile) {
        LOGMSG(l_ERROR, "No input file/dir specified");
        return false;
    }

    struct stat st;
    if (stat(hfuzz->inputFile, &st) == -1) {
        LOGMSG_P(l_ERROR, "Couldn't stat the input file/dir '%s'", hfuzz->inputFile);
        return false;
    }

    if (S_ISDIR(st.st_mode)) {
        return files_readdir(hfuzz);
    }

    if (!S_ISREG(st.st_mode)) {
        LOGMSG(l_ERROR, "'%s' is not a regular file, nor a directory", hfuzz->inputFile);
        return false;
    }

    hfuzz->files[0] = hfuzz->inputFile;
    hfuzz->fileCnt = 1;

    return true;
}