trace.con commit t8001/t8002: blame: demonstrate -L bounds checking bug (580b4f3)
   1/*
   2 * GIT - The information manager from hell
   3 *
   4 * Copyright (C) 2000-2002 Michael R. Elkins <me@mutt.org>
   5 * Copyright (C) 2002-2004 Oswald Buddenhagen <ossi@users.sf.net>
   6 * Copyright (C) 2004 Theodore Y. Ts'o <tytso@mit.edu>
   7 * Copyright (C) 2006 Mike McCormack
   8 * Copyright (C) 2006 Christian Couder
   9 *
  10 *  This program is free software; you can redistribute it and/or modify
  11 *  it under the terms of the GNU General Public License as published by
  12 *  the Free Software Foundation; either version 2 of the License, or
  13 *  (at your option) any later version.
  14 *
  15 *  This program is distributed in the hope that it will be useful,
  16 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 *  GNU General Public License for more details.
  19 *
  20 *  You should have received a copy of the GNU General Public License
  21 *  along with this program; if not, write to the Free Software
  22 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  23 */
  24
  25#include "cache.h"
  26#include "quote.h"
  27
  28/* Get a trace file descriptor from "key" env variable. */
  29static int get_trace_fd(const char *key, int *need_close)
  30{
  31        char *trace = getenv(key);
  32
  33        if (!trace || !strcmp(trace, "") ||
  34            !strcmp(trace, "0") || !strcasecmp(trace, "false"))
  35                return 0;
  36        if (!strcmp(trace, "1") || !strcasecmp(trace, "true"))
  37                return STDERR_FILENO;
  38        if (strlen(trace) == 1 && isdigit(*trace))
  39                return atoi(trace);
  40        if (is_absolute_path(trace)) {
  41                int fd = open(trace, O_WRONLY | O_APPEND | O_CREAT, 0666);
  42                if (fd == -1) {
  43                        fprintf(stderr,
  44                                "Could not open '%s' for tracing: %s\n"
  45                                "Defaulting to tracing on stderr...\n",
  46                                trace, strerror(errno));
  47                        return STDERR_FILENO;
  48                }
  49                *need_close = 1;
  50                return fd;
  51        }
  52
  53        fprintf(stderr, "What does '%s' for %s mean?\n", trace, key);
  54        fprintf(stderr, "If you want to trace into a file, "
  55                "then please set %s to an absolute pathname "
  56                "(starting with /).\n", key);
  57        fprintf(stderr, "Defaulting to tracing on stderr...\n");
  58
  59        return STDERR_FILENO;
  60}
  61
  62static const char err_msg[] = "Could not trace into fd given by "
  63        "GIT_TRACE environment variable";
  64
  65static void trace_vprintf(const char *key, const char *fmt, va_list ap)
  66{
  67        struct strbuf buf = STRBUF_INIT;
  68
  69        if (!trace_want(key))
  70                return;
  71
  72        set_try_to_free_routine(NULL);  /* is never reset */
  73        strbuf_vaddf(&buf, fmt, ap);
  74        trace_strbuf(key, &buf);
  75        strbuf_release(&buf);
  76}
  77
  78__attribute__((format (printf, 2, 3)))
  79static void trace_printf_key(const char *key, const char *fmt, ...)
  80{
  81        va_list ap;
  82        va_start(ap, fmt);
  83        trace_vprintf(key, fmt, ap);
  84        va_end(ap);
  85}
  86
  87void trace_printf(const char *fmt, ...)
  88{
  89        va_list ap;
  90        va_start(ap, fmt);
  91        trace_vprintf("GIT_TRACE", fmt, ap);
  92        va_end(ap);
  93}
  94
  95void trace_strbuf(const char *key, const struct strbuf *buf)
  96{
  97        int fd, need_close = 0;
  98
  99        fd = get_trace_fd(key, &need_close);
 100        if (!fd)
 101                return;
 102
 103        write_or_whine_pipe(fd, buf->buf, buf->len, err_msg);
 104
 105        if (need_close)
 106                close(fd);
 107}
 108
 109void trace_argv_printf(const char **argv, const char *fmt, ...)
 110{
 111        struct strbuf buf = STRBUF_INIT;
 112        va_list ap;
 113        int fd, need_close = 0;
 114
 115        fd = get_trace_fd("GIT_TRACE", &need_close);
 116        if (!fd)
 117                return;
 118
 119        set_try_to_free_routine(NULL);  /* is never reset */
 120        va_start(ap, fmt);
 121        strbuf_vaddf(&buf, fmt, ap);
 122        va_end(ap);
 123
 124        sq_quote_argv(&buf, argv, 0);
 125        strbuf_addch(&buf, '\n');
 126        write_or_whine_pipe(fd, buf.buf, buf.len, err_msg);
 127        strbuf_release(&buf);
 128
 129        if (need_close)
 130                close(fd);
 131}
 132
 133static const char *quote_crnl(const char *path)
 134{
 135        static char new_path[PATH_MAX];
 136        const char *p2 = path;
 137        char *p1 = new_path;
 138
 139        if (!path)
 140                return NULL;
 141
 142        while (*p2) {
 143                switch (*p2) {
 144                case '\\': *p1++ = '\\'; *p1++ = '\\'; break;
 145                case '\n': *p1++ = '\\'; *p1++ = 'n'; break;
 146                case '\r': *p1++ = '\\'; *p1++ = 'r'; break;
 147                default:
 148                        *p1++ = *p2;
 149                }
 150                p2++;
 151        }
 152        *p1 = '\0';
 153        return new_path;
 154}
 155
 156/* FIXME: move prefix to startup_info struct and get rid of this arg */
 157void trace_repo_setup(const char *prefix)
 158{
 159        static const char *key = "GIT_TRACE_SETUP";
 160        const char *git_work_tree;
 161        char cwd[PATH_MAX];
 162
 163        if (!trace_want(key))
 164                return;
 165
 166        if (!getcwd(cwd, PATH_MAX))
 167                die("Unable to get current working directory");
 168
 169        if (!(git_work_tree = get_git_work_tree()))
 170                git_work_tree = "(null)";
 171
 172        if (!prefix)
 173                prefix = "(null)";
 174
 175        trace_printf_key(key, "setup: git_dir: %s\n", quote_crnl(get_git_dir()));
 176        trace_printf_key(key, "setup: worktree: %s\n", quote_crnl(git_work_tree));
 177        trace_printf_key(key, "setup: cwd: %s\n", quote_crnl(cwd));
 178        trace_printf_key(key, "setup: prefix: %s\n", quote_crnl(prefix));
 179}
 180
 181int trace_want(const char *key)
 182{
 183        const char *trace = getenv(key);
 184
 185        if (!trace || !strcmp(trace, "") ||
 186            !strcmp(trace, "0") || !strcasecmp(trace, "false"))
 187                return 0;
 188        return 1;
 189}