Security-57031.40.6.tar.gz

[apple/security.git] / Security / libsecurity_utilities / lib / debugging.cpp

/*
 * Copyright (c) 2000-2004,2011-2012,2014 Apple Inc. All Rights Reserved.
 * 
 * @APPLE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */


//
// debugging - non-trivial debugging support
//
#include <security_utilities/debugsupport.h>
#include <security_utilities/globalizer.h>
#include <cstdarg>
#include <ctype.h>

#define SYSLOG_NAMES            // compile syslog name tables
#include <syslog.h>

#include <cxxabi.h>                     // for name demangling
#include <mach-o/dyld.h>        // for _NSGetExecutablePath
#include <limits.h>

// enable kernel tracing
#define ENABLE_SECTRACE 1


namespace Security {
namespace Debug {


//
// Dump facility
//
bool dumping(const char *scope)
{
#if defined(NDEBUG_STUBS)
    return false;
#else
        return Target::get().dump(scope);
#endif
}

void dump(const char *format, ...)
{
#if !defined(NDEBUG_CODE)
        va_list args;
        va_start(args, format);
        Target::get().dump(format, args);
        va_end(args);
#endif
}

void dumpData(const void *ptr, size_t size)
{
#if !defined(NDEBUG_CODE)
        const char *addr = reinterpret_cast<const char *>(ptr);
        const char *end = addr + size;
        bool isText = true;
        for (const char *p = addr; p < end; p++)
                if (!isprint(*p)) { isText = false; break; }
                
        if (isText) {
                dump("\"");
                for (const char *p = addr; p < end; p++)
                        dump("%c", *p);
                dump("\"");
        } else {
                dump("0x");
                for (const char *p = addr; p < end; p++)
                        dump("%2.2x", static_cast<unsigned char>(*p));
        }
#endif //NDEBUG_STUBS
}

void dumpData(const char *title, const void *ptr, size_t size)
{
#if !defined(NDEBUG_CODE)
        dump("%s: ", title);
        dumpData(ptr, size);
        dump("\n");
#endif //NDEBUG_STUBS
}


//
// Turn a C++ typeid into a nice type name.
// This uses the C++ ABI where available.
// We're stripping out a few C++ prefixes; they're pretty redundant (and obvious).
//
string makeTypeName(const type_info &type)
{
        int status;
        char *cname = abi::__cxa_demangle(type.name(), NULL, NULL, &status);
        string name = !strncmp(cname, "Security::", 10) ? (cname + 10) :
                !strncmp(cname, "std::", 5) ? (cname + 5) :
                cname;
        ::free(cname);  // yes, really (ABI rules)
        return name;
}


//
// Target initialization.
// This where we should do all "first time" initializations.
//
#if !defined(NDEBUG_CODE)

char Target::progName[maxProgNameLength + 1];
unsigned int Target::PerThread::lastUsed;

Target::Target() 
        : showScope(false), showThread(false), showProc(false), showDate(false),
          sink(NULL)
{
        // put into singleton slot if first
        if (singleton == NULL)
                singleton = this;
        
        // insert terminate handler
        if (!previousTerminator)        // first time we do this
                previousTerminator = set_terminate(terminator);
        
        // get program name
        char execPath[PATH_MAX];
        uint32_t length = sizeof(execPath);
        if (_NSGetExecutablePath(execPath, &length)) {
                strcpy(progName, "unknown");
        } else {
                const char *p = strrchr(execPath, '/');
                if (p)
                        p++;
                else
                        p = execPath;
                size_t plen = strlen(p);
                if (plen > maxProgNameLength)           // too long
                        p += plen - maxProgNameLength; // take rear
                strcpy(progName, p);
        }
}

Target::~Target()
{
}


static void addScope(char *&bufp, const char *scope)
{
        if (const char *sep = strchr(scope, ',')) {
                bufp += sprintf(bufp, "%-*s", Name::maxLength, (const char *)Name(scope, sep));
        } else {    // single scope
                bufp += sprintf(bufp, "%-*s", Name::maxLength, scope);
        }
}


//
// The core logging function of a Target
//
void Target::message(const char *scope, const char *format, va_list args)
{
        if (logSelector(scope)) {
                // note: messageConstructionSize is big enough for all prefixes constructed
                char buffer[messageConstructionSize];   // building the message here
                char *bufp = buffer;

                // date option
                if (showDate && sink->needsDate) {
                        time_t now = time(NULL);
                        char *date = ctime(&now);
                        date[19] = '\0';
                        bufp += sprintf(bufp, "%s ", date + 4); // Nov 24 18:22:48
                }

                // leading scope
                if (showScope && scope)
                        addScope(bufp, scope);
                
                if (showProc || showThread) {
                        char sub[maxProgNameLength + 20];
                        unsigned plen = 0;
                        if (showProc && showThread)
                                plen = sprintf(sub, "%s[%d]", progName, getpid());
                        else if (showProc)
                                plen = sprintf(sub, "%s", progName);
                        else
                                plen = sprintf(sub, "[%d]", getpid());
                        unsigned int id = perThread().id;
                        if (id > 1)
                                plen += sprintf(sub + plen, ":%d", id);
                        if (plen <= procLength)
                                bufp += sprintf(bufp, "%-*s ", int(procLength), sub);
                        else
                                bufp += sprintf(bufp, "%s ", sub + plen - procLength);
                }

                // scope after proc/thread/pid
                if (showScopeRight && scope)
                        addScope(bufp, scope);

                // now stuff the message body in, slightly roasted
                size_t left = buffer + sizeof(buffer) - bufp - 1;       // reserve one
                size_t written = vsnprintf(bufp, left, format, args);
        for (char *p = bufp; *p; p++)
            if (!isprint(*p))
                *p = '?';
                if (written >= left) {  // snprintf overflowed
                        bufp += left;
                        strcpy(bufp - 3, "...");
                } else
                        bufp += written;
                
                // now append a newline and a null
                bufp[0] = '\n';
                bufp[1] = '\0';

                // submit to sink (do not count newline and null in count)
                sink->put(buffer, (unsigned int)(bufp - buffer));
        }
}

bool Target::debugging(const char *scope)
{
        return logSelector(scope);
}


//
// The core debug-dump function of a target
//
void Target::dump(const char *format, va_list args)
{
        char buffer[messageConstructionSize];   // building the message here
        vsnprintf(buffer, sizeof(buffer), format, args);
        for (char *p = buffer; *p; p++)
                if ((!isprint(*p) && !isspace(*p)) || *p == '\r')
                        *p = '?';
        sink->dump(buffer);
}

bool Target::dump(const char *scope)
{
        return dumpSelector(scope);
}


//
// Selector objects.
//
Target::Selector::Selector() : useSet(false), negate(false)
{ }

void Target::Selector::operator = (const char *scope)
{
        if (scope) {
                // initial values
                if (!strcmp(scope, "all")) {
                        useSet = false;
                        negate = true;
                } else if (!strcmp(scope, "none")) {
                        useSet = negate = false;
                } else {
                        useSet = true;
                        enableSet.erase(enableSet.begin(), enableSet.end());
                        if (scope[0] == '-') {
                                negate = true;
                                scope++;
                        } else
                                negate = false;
                        while (const char *sep = strchr(scope, ',')) {
                                enableSet.insert(Name(scope, sep));
                                scope = sep + 1;
                        }
                        enableSet.insert(scope);
                }
        } else {
                useSet = negate = false;
        }
}

bool Target::Selector::operator () (const char *scope) const
{
        // a scope of NULL is a special override; it always qualifies
        if (scope == NULL)
                return true;

        if (useSet) {
                while (const char *sep = strchr(scope, ',')) {
                        if (enableSet.find(Name(scope, sep)) != enableSet.end())
                                return !negate;
                        scope = sep + 1;
                }
                return (enableSet.find(scope) != enableSet.end()) != negate;
        } else {
                return negate;
        }
}


//
// Establish Target state from the environment
//
void Target::setFromEnvironment()
{
        // set scopes
        logSelector = getenv("DEBUGSCOPE");
        dumpSelector = getenv("DEBUGDUMP");
        
        //
        // Set and configure destination. Currently available:
        //      /some/where -> that file
        //      LOG_SOMETHING -> syslog facility
        //      >&number -> that (already) open (for write or append) file descriptor
        //      anything else -> try as a filename sight unseen [may change]
        //      DEBUGDEST not set -> stderr
        //      anything in error -> stderr (with an error message on it)
        //
        if (const char *dest = getenv("DEBUGDEST")) {
                if (dest[0] == '/') {   // full pathname, write to file
                        to(dest);
                } else if (!strncmp(dest, "LOG_", 4)) { // syslog
                        int facility = LOG_DAEMON;
                        for (CODE *cp = facilitynames; cp->c_name; cp++)
                                if (!strcmp(dest, cp->c_name))
                                        facility = cp->c_val;
                        to(facility | LOG_DEBUG);
                } else if (!strncmp(dest, ">&", 2)) {   // to file descriptor
                        int fd = atoi(dest+2);
                        if (FILE *f = fdopen(fd, "a")) {
                                to(f);
                        } else {
                                to(stderr);
                                secdebug("", "cannot log to fd[%d]: %s", fd, strerror(errno));
                        }
                } else {        // if everything else fails, write a file
                        to(dest);
                }
        } else {                // default destination is stderr
                to(stderr);
        }
        configure();
}


void Target::configure()
{
        configure(getenv("DEBUGOPTIONS"));
}

void Target::configure(const char *config)
{
        // configure global options
        showScopeRight = config && strstr(config, "rscope");
        showScope = !showScopeRight && config && strstr(config, "scope");
        showThread = config && (strstr(config, "thread") || strstr(config, "pid")); // (legacy)
        showProc = config && strstr(config, "proc");
        showDate = config && strstr(config, "date");

        // configure sink
        if (sink)
                sink->configure(config);
}


//
// Explicit destination assignments
//
void Target::to(Sink *s)
{               
        delete sink;    
        sink = s;
}

void Target::to(FILE *file)
{
        to(new FileSink(file));
}

void Target::to(const char *filename)
{
        if (FILE *f = fopen(filename, "a")) {
                to(new FileSink(f));
        } else {
                to(stderr);
                secdebug("", "cannot debug to \"%s\": %s", filename, strerror(errno));
        }
}

void Target::to(int syslogPriority)
{
        to(new SyslogSink(syslogPriority));
}


//
// Making and retrieving the default singleton
//
Target *Target::singleton;

Target &Target::get()
{
        if (singleton == NULL) {
                Target *t = new Target;
                t->setFromEnvironment();
        }
        return *singleton;
}


//
// Standard sink implementations
//
Target::Sink::~Sink()
{ }

void Target::Sink::dump(const char *)
{ }

void Target::Sink::configure(const char *)
{ }


//
// The terminate handler installed when a Target is created
//
terminate_handler Target::previousTerminator;

void Target::terminator()
{
        secdebug("exception", "uncaught exception terminates program");
        previousTerminator();
        secdebug("exception", "prior termination handler failed to abort; forcing abort");
        abort();
}


//
// File sinks (write to file via stdio)
//
void FileSink::put(const char *inbuf, unsigned int length)
{
        fwrite(inbuf, 1, length + 1, file);     // do pick up the trailing newline
}

void FileSink::dump(const char *text)
{
        fputs(text, file);
}

void FileSink::configure(const char *options)
{
        if (options == NULL || !strstr(options, "noflush")) {
                // we mean "if the file isn't unbuffered", but what's the portable way to say that?
                if (file != stderr)
                        setlinebuf(file);
        }
}


//
// Syslog sinks (write to syslog)
//
void SyslogSink::put(const char *buffer, unsigned int length)
{
        syslog(priority, "%1.*s", length, buffer); // don't pick up trailing newline
}

void SyslogSink::dump(const char *text)
{
        // add to dump buffer
        snprintf(dumpPtr, dumpBuffer + dumpBufferSize - dumpPtr, "%s", text);
        
        // take off full lines and submit
        char *p = dumpBase;
        while (char *q = strchr(p, '\n')) {
                *q++ = '\0';    // terminate/break
                syslog(priority, " @@ %s", p);
                p = q;
        }
        
        if (*p) {       // left-over unterminated line segment in buffer
                dumpPtr = p + strlen(p);
                if ((dumpBase = p) > dumpBuffer + dumpBufferSize / 2) {
                        // shift buffer down to make room
                        memmove(dumpBuffer, dumpBase, dumpPtr - dumpBase);
                        dumpPtr -= (dumpBase - dumpBuffer);
                        dumpBase = dumpBuffer;
                }
        } else {        // buffer is empty; reset to start
                dumpBase = dumpPtr = dumpBuffer;
        }
}

void SyslogSink::configure(const char *options)
{
}

#endif //NDEBUG_CODE


} // end namespace Debug
} // end namespace Security