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C

// SPDX-License-Identifier: GPL-3.0-or-later
/**
* \file bgpgrep.c
*
* `bgpgrep` main entry point and general command line parsing.
*
* \copyright The DoubleFourteen Code Forge (C) All Rights Reserved
* \author Lorenzo Cogotti
*/
#include "bgpgrep_local.h"
#include "bgp/bgp.h"
#include "bgp/bytebuf.h"
#include "bgp/patricia.h"
#include "cpr/flate.h"
#include "cpr/bzip2.h"
#include "cpr/xz.h"
#include "sys/fs.h"
#include "sys/con.h"
#include "sys/sys.h"
#include "sys/vt100.h"
#include "argv.h"
#include "strlib.h"
#include <assert.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#define BYTEBUFSIZ (256 * 1024)
static BGP_FIXBYTEBUF(BYTEBUFSIZ) bgp_msgBuf = { BYTEBUFSIZ };
BgpgrepState S;
typedef enum {
NO_COLOR_FLAG,
DUMP_BYTECODE_FLAG,
OUTPUT_FLAG,
NUM_FLAGS
} BgpgrepOpt;
static Optflag options[] = {
[NO_COLOR_FLAG] = {
'-', "no-color", NULL, "Disable color output", ARG_NONE
},
[DUMP_BYTECODE_FLAG] = {
'-', "dump-bytecode", NULL, "Dump BGP VM bytecode to stderr (debug)", ARG_NONE
},
[OUTPUT_FLAG] = {
'o', NULL, "file", "Write output to file", ARG_REQ
},
[NUM_FLAGS] = { '\0' }
};
static void Bgpgrep_SetupCommandLine(char *argv0)
{
Sys_StripPath(argv0, NULL);
Sys_StripFileExtension(argv0, NULL);
com_progName = argv0;
com_synopsis = "[OPTIONS...] [FILES...]";
com_shortDescr = "Filter and print BGP data within MRT dumps";
com_longDescr =
"Reads MRT dumps in various formats, applying filtering rules\n"
"to each BGP message therein, then outputs every passing message\n"
"to stdout (or any custom output file defined by OPTIONS).\n"
"If - is found inside FILES, then input is read from stdin.\n"
"If no FILES arguments are provided, then input\n"
"is implicitly expected from stdin.\n"
"Any diagnostic message is logged to stderr.";
}
void Bgpgrep_Fatal(const char *fmt, ...)
{
va_list va;
Sys_Print(STDERR, com_progName);
Sys_Print(STDERR, ": ERROR: ");
va_start(va, fmt);
Sys_VPrintf(STDERR, fmt, va);
va_end(va);
Sys_Print(STDERR, "\n");
exit(EXIT_FAILURE);
}
void Bgpgrep_Warning(const char *fmt, ...)
{
va_list va;
Sys_Print(STDERR, com_progName);
Sys_Print(STDERR, ": ");
if (S.filename) {
Sys_Print(STDERR, S.filename);
Sys_Print(STDERR, ": ");
}
Sys_Print(STDERR, "WARNING: ");
va_start(va, fmt);
Sys_VPrintf(STDERR, fmt, va);
va_end(va);
Sys_Print(STDERR, "\n");
}
static void Bgpgrep_ApplyProgramOptions(void)
{
S.noColor = options[NO_COLOR_FLAG].flagged;
S.dumpBytecode = options[DUMP_BYTECODE_FLAG].flagged;
if (options[OUTPUT_FLAG].flagged) {
const char *filename = options[OUTPUT_FLAG].optarg;
Fildes fd = Sys_Fopen(filename, FM_WRITE, /*hints=*/0);
if (fd == FILDES_BAD)
Bgpgrep_Fatal("Can't open output file \"%s\"", filename);
S.outf = STM_FILDES(fd);
S.outfOps = Stm_FildesOps;
S.noColor = TRUE;
} else {
S.outf = STM_CONHN(STDOUT);
S.outfOps = Stm_ConOps;
}
if (!S.noColor && Sys_IsVt100Console(STDOUT))
S.outFmt = Bgp_IsolarioFmtWc; // console supports colors
else
S.outFmt = Bgp_IsolarioFmt;
}
static int CountFileArguments(int argc, char **argv)
{
int i;
for (i = 0; i < argc; i++) {
const char *arg = argv[i];
if (arg[0] == '-' && arg[1] != '\0')
break;
if (strcmp(arg, "(") == 0 || strcmp(arg, "!") == 0)
break;
}
return i;
}
void Bgpgrep_DropMessage(const char *fmt, ...)
{
va_list va;
Sys_Print(STDERR, com_progName);
Sys_Print(STDERR, ": ");
assert(S.filename);
Sys_Print(STDERR, S.filename);
Sys_Print(STDERR, ": ");
va_start(va, fmt);
Sys_VPrintf(STDERR, fmt, va);
va_end(va);
Sys_Print(STDERR, "\n");
Bgp_ClearMsg(&S.msg);
S.nerrors++;
longjmp_fast(S.dropMsgFrame);
}
void Bgpgrep_DropRecord(const char *fmt, ...)
{
va_list va;
Sys_Print(STDERR, com_progName);
Sys_Print(STDERR, ": ");
assert(S.filename);
Sys_Print(STDERR, S.filename);
Sys_Print(STDERR, ": ");
va_start(va, fmt);
Sys_VPrintf(STDERR, fmt, va);
va_end(va);
Sys_Print(STDERR, "\n");
S.nerrors++;
S.lenientBgpErrors = FALSE; // reset for future files
// If we're dropping a record we have to kill S.rec and S.msg
Bgp_ClearMsg(&S.msg);
Bgp_ClearMrt(&S.rec);
// ...but don't drop PEER_INDEX_TABLE
longjmp_fast(S.dropRecordFrame);
}
void Bgpgrep_DropFile(const char *fmt, ...)
{
va_list va;
Sys_Print(STDERR, com_progName);
Sys_Print(STDERR, ": ");
assert(S.filename);
Sys_Print(STDERR, S.filename);
Sys_Print(STDERR, ": ");
va_start(va, fmt);
Sys_VPrintf(STDERR, fmt, va);
va_end(va);
Sys_Print(STDERR, "\n");
S.nerrors++;
S.lenientBgpErrors = FALSE; // reset for future files
// Must clear PEER_INDEX_TABLE also, along with S.rec and S.msg...
Bgp_ClearMsg(&S.msg);
Bgp_ClearMrt(&S.rec);
Bgp_ClearMrt(&S.peerIndex);
S.hasPeerIndex = FALSE;
// Finally close current file and jump
if (S.infOps) {
if (S.infOps->Close) S.infOps->Close(S.inf);
S.inf = NULL;
S.infOps = NULL;
}
S.filename = NULL;
longjmp_fast(S.dropFileFrame);
}
// Common error management for BGP layer
NOINLINE static void Bgpgrep_HandleBgpError(BgpRet err, Srcloc *loc, void *obj)
{
USED(obj);
if (err == BGPEVMMSGERR)
err = Bgp_GetErrStat(NULL); // retrieve the actual BGP error
// Hopefully we are not dealing with a programming error...
assert(err != BGPEBADMRTTYPE);
assert(err != BGPENOADDPATH);
assert(err != BGPEBADTYPE && err != BGPEBADATTRTYPE);
// On out of memory we die with an appropriate backtrace
if (err == BGPENOMEM) {
loc->call_depth++; // include this function itself
_Sys_OutOfMemory(loc->filename, loc->func, loc->line, loc->call_depth);
}
// BGP filter errors should never occur, but are theoretically
// possible when filters are excessively complex,
// we don't proceed any further since they may cause incomplete or
// misleading output data
if (BGP_ISVMERR(err))
Bgpgrep_Fatal("Unexpected BGP filter error: %s", Bgp_ErrorString(err));
// On I/O error we drop the entire file
if (err == BGPEIO)
Bgpgrep_DropFile("I/O error while reading MRT dump"); // TODO: better diagnostics
// Deal with critical MRT errors that cause a record drop
if (err == BGPETRUNCMRT || err == BGPETRUNCPEERV2 || err == BGPETRUNCRIBV2)
Bgpgrep_DropRecord("SKIPPING MRT RECORD: %s", Bgp_ErrorString(err));
if (BGP_ISMSGERR(err)) {
if (S.lenientBgpErrors) {
// Get away with just a warning
Bgpgrep_Warning("CORRUPT BGP MESSAGE: %s", Bgp_ErrorString(err));
S.nerrors++;
return;
}
// Drop the affected entry
Bgpgrep_DropMessage("SKIPPING BGP MESSAGE: %s", Bgp_ErrorString(err));
}
assert(BGP_ISMRTERR(err));
if (err == BGPEBADPEERIDXCNT || err == BGPEBADRIBV2CNT) {
// Only warrant a warning
Bgpgrep_Warning("CORRUPT MRT RECORD: %s", Bgp_ErrorString(err));
S.nerrors++;
return;
}
// Anything else causes a BGP drop
Bgpgrep_DropMessage("SKIPPING BGP MESSAGE: %s", Bgp_ErrorString(err));
}
static void Bgpgrep_Init(void)
{
Mrtrecord *rec = &S.rec;
Bgpmsg *msg = &S.msg;
rec->allocp = msg->allocp = &bgp_msgBuf;
rec->memOps = msg->memOps = Mem_BgpBufOps;
Bgp_InitVm(&S.vm, /*heapSize=*/0);
}
static void Bgpgrep_OpenMrtDump(const char *filename)
{
S.filename = filename;
if (strcmp(S.filename, "-") == 0) {
// Direct read from stdin - assume uncompressed.
Bufio_RdInit(&S.infBuf, STM_FILDES(CON_FILDES(STDIN)), Stm_NcFildesOps);
S.inf = &S.infBuf;
S.infOps = Stm_NcRdBufOps;
return;
}
Fildes fh = Sys_Fopen(S.filename, FM_READ, FH_SEQ);
if (fh == FILDES_BAD)
Bgpgrep_DropFile("Can't open file");
const char *ext = Sys_GetFileExtension(S.filename);
if (Df_stricmp(ext, ".bz2") == 0) {
S.inf = Bzip2_OpenDecompress(STM_FILDES(fh), Stm_FildesOps, /*opts=*/NULL);
S.infOps = Bzip2_StmOps;
Bzip2Ret err = Bzip2_GetErrStat();
if (err)
Bgpgrep_DropFile("Can't read Bz2 archive: %s", Bzip2_ErrorString(err));
} else if (Df_stricmp(ext, ".gz") == 0 || Df_stricmp(ext, ".z") == 0) {
S.inf = Zlib_InflateOpen(STM_FILDES(fh), Stm_FildesOps, /*opts=*/NULL);
S.infOps = Zlib_StmOps;
ZlibRet err = Zlib_GetErrStat();
if (err)
Bgpgrep_DropFile("Can't read Zlib archive: %s", Zlib_ErrorString(err));
} else if (Df_stricmp(ext, ".xz") == 0) {
S.inf = Xz_OpenDecompress(STM_FILDES(fh), Stm_FildesOps, /*opts=*/NULL);
S.infOps = Xz_StmOps;
XzRet err = Xz_GetErrStat();
if (err)
Bgpgrep_DropFile("Can't read LZMA archive: %s", Xz_ErrorString(err));
} else {
// Assume uncompressed file
Bufio_RdInit(&S.infBuf, STM_FILDES(fh), Stm_FildesOps);
S.inf = &S.infBuf;
S.infOps = Stm_RdBufOps;
}
}
static void Bgpgrep_ProcessMrtDump(const char *filename)
{
// NOTE: This call is responsible to set:
// S.filename, S.inf, S.infOps.
// These must be cleared either here or within a file drop.
Bgpgrep_OpenMrtDump(filename);
setjmp_fast(S.dropRecordFrame); // NOTE: The ONLY place where this is set
setjmp_fast(S.dropMsgFrame); // NOTE: May be set again by specific BgpgrepD_*()
while (Bgp_ReadMrt(&S.rec, S.inf, S.infOps) == OK) {
const Mrthdr *hdr = MRT_HDR(&S.rec);
switch (hdr->type) {
case MRT_TABLE_DUMPV2: BgpgrepD_TableDumpv2(); break;
case MRT_TABLE_DUMP: BgpgrepD_TableDump(); break;
case MRT_BGP: BgpgrepD_Zebra(); break;
default:
if (MRT_ISBGP4MP(hdr->type))
BgpgrepD_Bgp4mp();
break;
}
Bgp_ClearMrt(&S.rec);
}
// Don't need PEER_INDEX_TABLE anymore
Bgp_ClearMrt(&S.peerIndex);
S.hasPeerIndex = FALSE;
// Close input
if (S.infOps->Close) S.infOps->Close(S.inf);
S.inf = NULL;
S.infOps = NULL;
S.filename = NULL;
}
static int Bgpgrep_CleanupAndExit(void)
{
Bgp_ClearVm(&S.vm);
Trielist *t = S.trieList;
while (t) {
Trielist *tn = t->next;
Pat_Clear(&t->trie);
free(t);
t = tn;
}
if (S.outfOps->Close) S.outfOps->Close(S.outf);
return (S.nerrors > 0) ? EXIT_FAILURE : EXIT_SUCCESS;
}
int main(int argc, char **argv)
{
#ifndef NDEBUG
Sys_SetErrFunc(SYS_ERR_ABORT, NULL);
#else
Sys_SetErrFunc(SYS_ERR_QUIT, NULL);
#endif
Bgp_SetErrFunc(Bgpgrep_HandleBgpError, NULL);
// Initial program setup
Bgpgrep_SetupCommandLine(argv[0]);
int optind = Com_ArgParse(argc, argv, options, /*flags=*/ARG_NOREORD);
if (optind == OPT_HELP)
return EXIT_SUCCESS; // only called to get help...
if (optind < 0)
return EXIT_FAILURE; // can't parse command line
Bgpgrep_ApplyProgramOptions();
Bgpgrep_Init(); // initialize according to command line
// Done with options
argc -= optind;
argv += optind;
// Extrapolate files arguments from argv
char **files = argv;
int nfiles = CountFileArguments(argc, argv);
// Move to filtering rules and compile them
argv += nfiles;
argc -= nfiles;
Bgpgrep_CompileVmProgram(argc, argv);
if (nfiles == 0) {
// If no FILES are provided, read from stdin
static const char *const stdinFile[] = { "-" };
files = (char **) stdinFile;
nfiles = ARRAY_SIZE(stdinFile);
}
// Files processing
volatile int i = 0;
setjmp_fast(S.dropFileFrame); // NOTE: The ONLY place where this is set
while (i < nfiles)
Bgpgrep_ProcessMrtDump(files[i++]);
return Bgpgrep_CleanupAndExit();
}