/*
* Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000
*      The Regents of the University of California.  All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that: (1) source code distributions
* retain the above copyright notice and this paragraph in its entirety, (2)
* distributions including binary code include the above copyright notice and
* this paragraph in its entirety in the documentation or other materials
* provided with the distribution, and (3) all advertising materials mentioning
* features or use of this software display the following acknowledgement:
* ``This product includes software developed by the University of California,
* Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
* the University nor the names of its contributors may be used to endorse
* or promote products derived from this software without specific prior
* written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/

#include "varattrs.h"

/*
* This doesn't actually test libpcap itself; it tests whether
* valgrind properly handles the APIs libpcap uses.  If it doesn't,
* we end up getting patches submitted to "fix" references that
* valgrind claims are being made to uninitialized data, when, in
* fact, the OS isn't making any such references - or we get
* valgrind *not* detecting *actual* incorrect references.
*
* Both BPF and Linux socket filters aren't handled correctly
* by some versions of valgrind.  See valgrind bug 318203 for
* Linux:
*
*      https://bugs.kde.org/show_bug.cgi?id=318203
*
* and valgrind bug 312989 for macOS:
*
*      https://bugs.kde.org/show_bug.cgi?id=312989
*
* The fixes for both of those are checked into the official valgrind
* repository.
*
* The unofficial FreeBSD port has similar issues to the official macOS
* port, for similar reasons.
*/
#ifndef lint
static const char copyright[] _U_ =
   "@(#) Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000\n\
The Regents of the University of California.  All rights reserved.\n";
#endif

#include <config.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <limits.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <arpa/inet.h>
#include <sys/types.h>
#include <sys/stat.h>

#include "pcap/funcattrs.h"

#if defined(__APPLE__) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) || defined(_AIX) || defined(sun)
/* OS with BPF - use BPF */
#define USE_BPF
#elif defined(__linux__)
/* Linux - use socket filters */
#define USE_SOCKET_FILTERS
#else
#error "Unknown platform or platform that doesn't support Valgrind"
#endif

#if defined(USE_BPF)

#include <sys/ioctl.h>
#include <net/bpf.h>

/*
* Make "pcap.h" not include "pcap/bpf.h"; we are going to include the
* native OS version, as we're going to be doing our own ioctls to
* make sure that, in the uninitialized-data tests, the filters aren't
* checked by libpcap before being handed to BPF.
*/
#define PCAP_DONT_INCLUDE_PCAP_BPF_H

#elif defined(USE_SOCKET_FILTERS)

#include <sys/socket.h>
#include <linux/types.h>
#include <linux/filter.h>

#endif

/*
* Squelch a warning.
*
* We include system headers to be able to directly set the filter to
* a program with uninitialized content, to make sure what we're testing
* is Valgrind's checking of the system call to set the filter, and we
* also include <pcap.h> to open the device in the first place, and that
* means that we may get collisions between their definitions of
* BPF_STMT and BPF_JUMP - and do, in fact, get them on Linux (the
* definitions may be semantically the same, but that's not sufficient to
* avoid the warnings, as the preprocessor doesn't know that u_short is
* just unsigned short).
*
* So we undefine BPF_STMT and BPF_JUMP to avoid the warning.
*/
#undef BPF_STMT
#undef BPF_JUMP
#include <pcap.h>

static char *program_name;

/* Forwards */
static void PCAP_NORETURN usage(void);
static void PCAP_NORETURN error(const char *, ...) PCAP_PRINTFLIKE(1, 2);
static void warning(const char *, ...) PCAP_PRINTFLIKE(1, 2);

/*
* On Windows, we need to open the file in binary mode, so that
* we get all the bytes specified by the size we get from "fstat()".
* On UNIX, that's not necessary.  O_BINARY is defined on Windows;
* we define it as 0 if it's not defined, so it does nothing.
*/
#ifndef O_BINARY
#define O_BINARY        0
#endif

static char *
read_infile(char *fname)
{
       register int i, fd, cc;
       register char *cp;
       struct stat buf;

       fd = open(fname, O_RDONLY|O_BINARY);
       if (fd < 0)
               error("can't open %s: %s", fname, pcap_strerror(errno));

       if (fstat(fd, &buf) < 0)
               error("can't stat %s: %s", fname, pcap_strerror(errno));

       /*
        * _read(), on Windows, has an unsigned int byte count and an
        * int return value, so we can't handle a file bigger than
        * INT_MAX - 1 bytes (and have no reason to do so; a filter *that*
        * big will take forever to compile).  (The -1 is for the '\0' at
        * the end of the string.)
        */
       if (buf.st_size > INT_MAX - 1)
               error("%s is larger than %d bytes; that's too large", fname,
                   INT_MAX - 1);
       cp = malloc((u_int)buf.st_size + 1);
       if (cp == NULL)
               error("malloc(%d) for %s: %s", (u_int)buf.st_size + 1,
                       fname, pcap_strerror(errno));
       cc = (int)read(fd, cp, (u_int)buf.st_size);
       if (cc < 0)
               error("read %s: %s", fname, pcap_strerror(errno));
       if (cc != buf.st_size)
               error("short read %s (%d != %d)", fname, cc, (int)buf.st_size);

       close(fd);
       /* replace "# comment" with spaces */
       for (i = 0; i < cc; i++) {
               if (cp[i] == '#')
                       while (i < cc && cp[i] != '\n')
                               cp[i++] = ' ';
       }
       cp[cc] = '\0';
       return (cp);
}

/* VARARGS */
static void
error(const char *fmt, ...)
{
       va_list ap;

       (void)fprintf(stderr, "%s: ", program_name);
       va_start(ap, fmt);
       (void)vfprintf(stderr, fmt, ap);
       va_end(ap);
       if (*fmt) {
               fmt += strlen(fmt);
               if (fmt[-1] != '\n')
                       (void)fputc('\n', stderr);
       }
       exit(1);
       /* NOTREACHED */
}

/* VARARGS */
static void
warning(const char *fmt, ...)
{
       va_list ap;

       (void)fprintf(stderr, "%s: WARNING: ", program_name);
       va_start(ap, fmt);
       (void)vfprintf(stderr, fmt, ap);
       va_end(ap);
       if (*fmt) {
               fmt += strlen(fmt);
               if (fmt[-1] != '\n')
                       (void)fputc('\n', stderr);
       }
}

/*
* Copy arg vector into a new buffer, concatenating arguments with spaces.
*/
static char *
copy_argv(register char **argv)
{
       register char **p;
       register size_t len = 0;
       char *buf;
       char *src, *dst;

       p = argv;
       if (*p == 0)
               return 0;

       while (*p)
               len += strlen(*p++) + 1;

       buf = (char *)malloc(len);
       if (buf == NULL)
               error("copy_argv: malloc");

       p = argv;
       dst = buf;
       while ((src = *p++) != NULL) {
               while ((*dst++ = *src++) != '\0')
                       ;
               dst[-1] = ' ';
       }
       dst[-1] = '\0';

       return buf;
}

#define INSN_COUNT      17

int
main(int argc, char **argv)
{
       char *cp, *device;
       int op;
       int dorfmon, useactivate;
       char ebuf[PCAP_ERRBUF_SIZE];
       char *infile;
       const char *cmdbuf;
       pcap_if_t *devlist;
       pcap_t *pd;
       int status = 0;
       int pcap_fd;
#if defined(USE_BPF)
       struct bpf_program bad_fcode;
       struct bpf_insn uninitialized[INSN_COUNT];
#elif defined(USE_SOCKET_FILTERS)
       struct sock_fprog bad_fcode;
       struct sock_filter uninitialized[INSN_COUNT];
#endif
       struct bpf_program fcode;

       device = NULL;
       dorfmon = 0;
       useactivate = 0;
       infile = NULL;

       if ((cp = strrchr(argv[0], '/')) != NULL)
               program_name = cp + 1;
       else
               program_name = argv[0];

       opterr = 0;
       while ((op = getopt(argc, argv, "aF:i:I")) != -1) {
               switch (op) {

               case 'a':
                       useactivate = 1;
                       break;

               case 'F':
                       infile = optarg;
                       break;

               case 'i':
                       device = optarg;
                       break;

               case 'I':
                       dorfmon = 1;
                       useactivate = 1;        /* required for rfmon */
                       break;

               default:
                       usage();
                       /* NOTREACHED */
               }
       }

       if (device == NULL) {
               /*
                * No interface specified; get whatever pcap_lookupdev()
                * finds.
                */
               if (pcap_findalldevs(&devlist, ebuf) == -1)
                       error("%s", ebuf);
               if (devlist == NULL)
                       error("no interfaces available for capture");
               device = strdup(devlist->name);
               pcap_freealldevs(devlist);
       }

       if (infile != NULL) {
               /*
                * Filter specified with "-F" and a file containing
                * a filter.
                */
               cmdbuf = read_infile(infile);
       } else {
               if (optind < argc) {
                       /*
                        * Filter specified with arguments on the
                        * command line.
                        */
                       cmdbuf = copy_argv(&argv[optind+1]);
               } else {
                       /*
                        * No filter specified; use an empty string, which
                        * compiles to an "accept all" filter.
                        */
                       cmdbuf = "";
               }
       }

       if (useactivate) {
               pd = pcap_create(device, ebuf);
               if (pd == NULL)
                       error("%s: pcap_create() failed: %s", device, ebuf);
               status = pcap_set_snaplen(pd, 65535);
               if (status != 0)
                       error("%s: pcap_set_snaplen failed: %s",
                           device, pcap_statustostr(status));
               status = pcap_set_promisc(pd, 1);
               if (status != 0)
                       error("%s: pcap_set_promisc failed: %s",
                           device, pcap_statustostr(status));
               if (dorfmon) {
                       status = pcap_set_rfmon(pd, 1);
                       if (status != 0)
                               error("%s: pcap_set_rfmon failed: %s",
                                   device, pcap_statustostr(status));
               }
               status = pcap_set_timeout(pd, 1000);
               if (status != 0)
                       error("%s: pcap_set_timeout failed: %s",
                           device, pcap_statustostr(status));
               status = pcap_activate(pd);
               if (status < 0) {
                       /*
                        * pcap_activate() failed.
                        */
                       error("%s: %s\n(%s)", device,
                           pcap_statustostr(status), pcap_geterr(pd));
               } else if (status > 0) {
                       /*
                        * pcap_activate() succeeded, but it's warning us
                        * of a problem it had.
                        */
                       warning("%s: %s\n(%s)", device,
                           pcap_statustostr(status), pcap_geterr(pd));
               }
       } else {
               *ebuf = '\0';
               pd = pcap_open_live(device, 65535, 1, 1000, ebuf);
               if (pd == NULL)
                       error("%s", ebuf);
               else if (*ebuf)
                       warning("%s", ebuf);
       }

       pcap_fd = pcap_fileno(pd);

       /*
        * Try setting a filter with an uninitialized bpf_program
        * structure.  This should cause valgrind to report a
        * problem.
        *
        * We don't check for errors, because it could get an
        * error due to a bad pointer or count.
        */
#if defined(USE_BPF)
       ioctl(pcap_fd, BIOCSETF, &bad_fcode);
#elif defined(USE_SOCKET_FILTERS)
       setsockopt(pcap_fd, SOL_SOCKET, SO_ATTACH_FILTER, &bad_fcode,
           sizeof(bad_fcode));
#endif

       /*
        * Try setting a filter with an initialized bpf_program
        * structure that points to an uninitialized program.
        * That should also cause valgrind to report a problem.
        *
        * We don't check for errors, because it could get an
        * error due to a bad pointer or count.
        */
#if defined(USE_BPF)
       bad_fcode.bf_len = INSN_COUNT;
       bad_fcode.bf_insns = uninitialized;
       ioctl(pcap_fd, BIOCSETF, &bad_fcode);
#elif defined(USE_SOCKET_FILTERS)
       bad_fcode.len = INSN_COUNT;
       bad_fcode.filter = uninitialized;
       setsockopt(pcap_fd, SOL_SOCKET, SO_ATTACH_FILTER, &bad_fcode,
           sizeof(bad_fcode));
#endif

       /*
        * Now compile a filter and set the filter with that.
        * That should *not* cause valgrind to report a
        * problem.
        */
       if (pcap_compile(pd, &fcode, cmdbuf, 1, 0) < 0)
               error("can't compile filter: %s", pcap_geterr(pd));
       if (pcap_setfilter(pd, &fcode) < 0)
               error("can't set filter: %s", pcap_geterr(pd));

       pcap_close(pd);
       exit(status < 0 ? 1 : 0);
}

static void
usage(void)
{
       (void)fprintf(stderr, "%s, with %s\n", program_name,
           pcap_lib_version());
       (void)fprintf(stderr,
           "Usage: %s [-aI] [ -F file ] [ -i interface ] [ expression ]\n",
           program_name);
       exit(1);
}