diff options
Diffstat (limited to 'path.c')
| -rw-r--r-- | path.c | 165 |
1 files changed, 156 insertions, 9 deletions
@@ -157,6 +157,85 @@ int git_mkstemps(char *path, size_t len, const char *template, int suffix_len) return mkstemps(path, suffix_len); } +/* Adapted from libiberty's mkstemp.c. */ + +#undef TMP_MAX +#define TMP_MAX 16384 + +int git_mkstemps_mode(char *pattern, int suffix_len, int mode) +{ + static const char letters[] = + "abcdefghijklmnopqrstuvwxyz" + "ABCDEFGHIJKLMNOPQRSTUVWXYZ" + "0123456789"; + static const int num_letters = 62; + uint64_t value; + struct timeval tv; + char *template; + size_t len; + int fd, count; + + len = strlen(pattern); + + if (len < 6 + suffix_len) { + errno = EINVAL; + return -1; + } + + if (strncmp(&pattern[len - 6 - suffix_len], "XXXXXX", 6)) { + errno = EINVAL; + return -1; + } + + /* + * Replace pattern's XXXXXX characters with randomness. + * Try TMP_MAX different filenames. + */ + gettimeofday(&tv, NULL); + value = ((size_t)(tv.tv_usec << 16)) ^ tv.tv_sec ^ getpid(); + template = &pattern[len - 6 - suffix_len]; + for (count = 0; count < TMP_MAX; ++count) { + uint64_t v = value; + /* Fill in the random bits. */ + template[0] = letters[v % num_letters]; v /= num_letters; + template[1] = letters[v % num_letters]; v /= num_letters; + template[2] = letters[v % num_letters]; v /= num_letters; + template[3] = letters[v % num_letters]; v /= num_letters; + template[4] = letters[v % num_letters]; v /= num_letters; + template[5] = letters[v % num_letters]; v /= num_letters; + + fd = open(pattern, O_CREAT | O_EXCL | O_RDWR, mode); + if (fd > 0) + return fd; + /* + * Fatal error (EPERM, ENOSPC etc). + * It doesn't make sense to loop. + */ + if (errno != EEXIST) + break; + /* + * This is a random value. It is only necessary that + * the next TMP_MAX values generated by adding 7777 to + * VALUE are different with (module 2^32). + */ + value += 7777; + } + /* We return the null string if we can't find a unique file name. */ + pattern[0] = '\0'; + return -1; +} + +int git_mkstemp_mode(char *pattern, int mode) +{ + /* mkstemp is just mkstemps with no suffix */ + return git_mkstemps_mode(pattern, 0, mode); +} + +int gitmkstemps(char *pattern, int suffix_len) +{ + return git_mkstemps_mode(pattern, suffix_len, 0600); +} + int validate_headref(const char *path) { struct stat st; @@ -394,17 +473,38 @@ int set_shared_perm(const char *path, int mode) const char *make_relative_path(const char *abs, const char *base) { static char buf[PATH_MAX + 1]; - int baselen; - if (!base) - return abs; - baselen = strlen(base); - if (prefixcmp(abs, base)) + int i = 0, j = 0; + + if (!base || !base[0]) return abs; - if (abs[baselen] == '/') - baselen++; - else if (base[baselen - 1] != '/') + while (base[i]) { + if (is_dir_sep(base[i])) { + if (!is_dir_sep(abs[j])) + return abs; + while (is_dir_sep(base[i])) + i++; + while (is_dir_sep(abs[j])) + j++; + continue; + } else if (abs[j] != base[i]) { + return abs; + } + i++; + j++; + } + if ( + /* "/foo" is a prefix of "/foo" */ + abs[j] && + /* "/foo" is not a prefix of "/foobar" */ + !is_dir_sep(base[i-1]) && !is_dir_sep(abs[j]) + ) return abs; - strcpy(buf, abs + baselen); + while (is_dir_sep(abs[j])) + j++; + if (!abs[j]) + strcpy(buf, "."); + else + strcpy(buf, abs + j); return buf; } @@ -581,3 +681,50 @@ char *strip_path_suffix(const char *path, const char *suffix) return NULL; return xstrndup(path, chomp_trailing_dir_sep(path, path_len)); } + +int daemon_avoid_alias(const char *p) +{ + int sl, ndot; + + /* + * This resurrects the belts and suspenders paranoia check by HPA + * done in <435560F7.4080006@zytor.com> thread, now enter_repo() + * does not do getcwd() based path canonicalization. + * + * sl becomes true immediately after seeing '/' and continues to + * be true as long as dots continue after that without intervening + * non-dot character. + */ + if (!p || (*p != '/' && *p != '~')) + return -1; + sl = 1; ndot = 0; + p++; + + while (1) { + char ch = *p++; + if (sl) { + if (ch == '.') + ndot++; + else if (ch == '/') { + if (ndot < 3) + /* reject //, /./ and /../ */ + return -1; + ndot = 0; + } + else if (ch == 0) { + if (0 < ndot && ndot < 3) + /* reject /.$ and /..$ */ + return -1; + return 0; + } + else + sl = ndot = 0; + } + else if (ch == 0) + return 0; + else if (ch == '/') { + sl = 1; + ndot = 0; + } + } +} |