diff options
Diffstat (limited to 'path.c')
| -rw-r--r-- | path.c | 130 |
1 files changed, 97 insertions, 33 deletions
@@ -11,6 +11,7 @@ * which is what it's designed for. */ #include "cache.h" +#include "strbuf.h" static char bad_path[] = "/bad-path/"; @@ -207,43 +208,49 @@ int validate_headref(const char *path) return -1; } -static char *user_path(char *buf, char *path, int sz) +static struct passwd *getpw_str(const char *username, size_t len) { struct passwd *pw; - char *slash; - int len, baselen; + char *username_z = xmalloc(len + 1); + memcpy(username_z, username, len); + username_z[len] = '\0'; + pw = getpwnam(username_z); + free(username_z); + return pw; +} - if (!path || path[0] != '~') - return NULL; - path++; - slash = strchr(path, '/'); - if (path[0] == '/' || !path[0]) { - pw = getpwuid(getuid()); - } - else { - if (slash) { - *slash = 0; - pw = getpwnam(path); - *slash = '/'; +/* + * Return a string with ~ and ~user expanded via getpw*. If buf != NULL, + * then it is a newly allocated string. Returns NULL on getpw failure or + * if path is NULL. + */ +char *expand_user_path(const char *path) +{ + struct strbuf user_path = STRBUF_INIT; + const char *first_slash = strchrnul(path, '/'); + const char *to_copy = path; + + if (path == NULL) + goto return_null; + if (path[0] == '~') { + const char *username = path + 1; + size_t username_len = first_slash - username; + if (username_len == 0) { + const char *home = getenv("HOME"); + strbuf_add(&user_path, home, strlen(home)); + } else { + struct passwd *pw = getpw_str(username, username_len); + if (!pw) + goto return_null; + strbuf_add(&user_path, pw->pw_dir, strlen(pw->pw_dir)); } - else - pw = getpwnam(path); + to_copy = first_slash; } - if (!pw || !pw->pw_dir || sz <= strlen(pw->pw_dir)) - return NULL; - baselen = strlen(pw->pw_dir); - memcpy(buf, pw->pw_dir, baselen); - while ((1 < baselen) && (buf[baselen-1] == '/')) { - buf[baselen-1] = 0; - baselen--; - } - if (slash && slash[1]) { - len = strlen(slash); - if (sz <= baselen + len) - return NULL; - memcpy(buf + baselen, slash, len + 1); - } - return buf; + strbuf_add(&user_path, to_copy, strlen(to_copy)); + return strbuf_detach(&user_path, NULL); +return_null: + strbuf_release(&user_path); + return NULL; } /* @@ -291,8 +298,18 @@ char *enter_repo(char *path, int strict) if (PATH_MAX <= len) return NULL; if (path[0] == '~') { - if (!user_path(used_path, path, PATH_MAX)) + char *newpath = expand_user_path(path); + if (!newpath || (PATH_MAX - 10 < strlen(newpath))) { + free(newpath); return NULL; + } + /* + * Copy back into the static buffer. A pity + * since newpath was not bounded, but other + * branches of the if are limited by PATH_MAX + * anyway. + */ + strcpy(used_path, newpath); free(newpath); strcpy(validated_path, path); path = used_path; } @@ -564,3 +581,50 @@ 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 canonicalizations. + * + * 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; + } + } +} |