/*

 * Copyright (c) 2021-2022 Todd C. Miller <Todd.Miller@sudo.ws>

 *

 * Permission to use, copy, modify, and distribute this software for any

 * purpose with or without fee is hereby granted, provided that the above

 * copyright notice and this permission notice appear in all copies.

 *

 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES

 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF

 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR

 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES

 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN

 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF

 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

 */

#include <config.h>

#include <sys/types.h>

#include <sys/socket.h>

#include <netinet/in.h>

#include <arpa/inet.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <fcntl.h>

#include <limits.h>

#include <netdb.h>

#include <regex.h>

#include <time.h>

#include <unistd.h>

#if defined(HAVE_STDINT_H)

# include <stdint.h>

#elif defined(HAVE_INTTYPES_H)

# include <inttypes.h>

#endif

#include "sudo_compat.h"

#include "sudo_conf.h"

#include "sudo_debug.h"

#include "sudo_eventlog.h"

#include "sudo_fatal.h"

#include "sudo_iolog.h"

#include "sudo_plugin.h"

#include "sudo_util.h"

#include "logsrvd.h"

int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size);

/*

 * Stub version that always succeeds for small inputs and fails for large.

 * We want to fuzz our parser, not libc's regular expression code.

 */

bool

sudo_regex_compile_v1(void *v, const char *pattern, const char **errstr)

{

    regex_t *preg = v;

    if (strlen(pattern) > 32) {

  *errstr = "invalid regular expression";

  return false;

    }

    /* hopefully avoid regfree() crashes */

    memset(preg, 0, sizeof(*preg));

    return true;

}

/*

 * The fuzzing environment may not have DNS available, this may result

 * in long delays that cause a timeout when fuzzing.

 * This getaddrinfo() resolves every name as "localhost" (127.0.0.1).

 */

#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION

/* Avoid compilation errors if getaddrinfo() or freeaddrinfo() are macros. */

# undef getaddrinfo

# undef freeaddrinfo

int

# ifdef HAVE_GETADDRINFO

getaddrinfo(

# else

sudo_getaddrinfo(

# endif

    const char *nodename, const char *servname,

    const struct addrinfo *hints, struct addrinfo **res)

{

    struct addrinfo *ai;

    struct in_addr addr;

    unsigned short port = 0;

    /* Stub getaddrinfo(3) to avoid a DNS timeout in CIfuzz. */

    if (servname == NULL) {

  /* Must have either nodename or servname. */

  if (nodename == NULL)

      return EAI_NONAME;

    } else {

  struct servent *servent;

  const char *errstr;

  /* Parse servname as a port number or IPv4 TCP service name. */

  port = sudo_strtonum(servname, 0, USHRT_MAX, &errstr);

  if (errstr != NULL && errno == ERANGE)

      return EAI_SERVICE;

  if (hints != NULL && ISSET(hints->ai_flags, AI_NUMERICSERV))

      return EAI_NONAME;

  servent = getservbyname(servname, "tcp");

  if (servent == NULL)

      return EAI_NONAME;

  port = htons(servent->s_port);

    }

    /* Hard-code IPv4 localhost for fuzzing. */

    ai = calloc(1, sizeof(*ai) + sizeof(struct sockaddr_in));

    if (ai == NULL)

  return EAI_MEMORY;

    ai->ai_canonname = strdup("localhost");

    if (ai == NULL) {

  free(ai);

  return EAI_MEMORY;

    }

    ai->ai_family = AF_INET;

    ai->ai_protocol = IPPROTO_TCP;

    ai->ai_addrlen = sizeof(struct sockaddr_in);

    ai->ai_addr = (struct sockaddr *)(ai + 1);

    inet_pton(AF_INET, "127.0.0.1", &addr);

    ((struct sockaddr_in *)ai->ai_addr)->sin_family = AF_INET;

    ((struct sockaddr_in *)ai->ai_addr)->sin_addr = addr;

    ((struct sockaddr_in *)ai->ai_addr)->sin_port = htons(port);

    *res = ai;

    return 0;

}

void

# ifdef HAVE_GETADDRINFO

freeaddrinfo(struct addrinfo *ai)

# else

sudo_freeaddrinfo(struct addrinfo *ai)

# endif

{

    struct addrinfo *next;

    while (ai != NULL) {

  next = ai->ai_next;

  free(ai->ai_canonname);

  free(ai);

  ai = next;

    }

}

#endif /* FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION */

static int

fuzz_conversation(int num_msgs, const struct sudo_conv_message msgs[],

    struct sudo_conv_reply replies[], struct sudo_conv_callback *callback)

{

    int n;

    for (n = 0; n < num_msgs; n++) {

  const struct sudo_conv_message *msg = &msgs[n];

  switch (msg->msg_type & 0xff) {

      case SUDO_CONV_PROMPT_ECHO_ON:

      case SUDO_CONV_PROMPT_MASK:

      case SUDO_CONV_PROMPT_ECHO_OFF:

    /* input not supported */

    return -1;

      case SUDO_CONV_ERROR_MSG:

      case SUDO_CONV_INFO_MSG:

    /* no output for fuzzers */

    break;

      default:

    return -1;

  }

    }

    return 0;

}

int

LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)

{

    char tempfile[] = "/tmp/logsrvd_conf.XXXXXX";

    size_t nwritten;

    int fd;

    initprogname("fuzz_logsrvd_conf");

    if (getenv("SUDO_FUZZ_VERBOSE") == NULL)

  sudo_warn_set_conversation(fuzz_conversation);

    /* logsrvd_conf_read() uses a conf file path, not an open file. */

    fd = mkstemp(tempfile);

    if (fd == -1)

  return 0;

    nwritten = write(fd, data, size);

    if (nwritten != size) {

  close(fd);

  return 0;

    }

    close(fd);

    if (logsrvd_conf_read(tempfile)) {

  /* public config getters */

  logsrvd_conf_iolog_dir();

  logsrvd_conf_iolog_file();

  logsrvd_conf_iolog_mode();

  logsrvd_conf_pid_file();

  logsrvd_conf_relay_address();

  logsrvd_conf_relay_connect_timeout();

  logsrvd_conf_relay_tcp_keepalive();

  logsrvd_conf_relay_timeout();

  logsrvd_conf_server_listen_address();

  logsrvd_conf_server_tcp_keepalive();

  logsrvd_conf_server_timeout();

  /* free config */

  logsrvd_conf_cleanup();

    }

    unlink(tempfile);

    fflush(stdout);

    return 0;

}