diff options
Diffstat (limited to 'cmds/installd/utils.c')
| -rw-r--r-- | cmds/installd/utils.c | 259 |
1 files changed, 248 insertions, 11 deletions
diff --git a/cmds/installd/utils.c b/cmds/installd/utils.c index a5e4b5a1557d..f37a6fbae152 100644 --- a/cmds/installd/utils.c +++ b/cmds/installd/utils.c @@ -16,24 +16,93 @@ #include "installd.h" +int create_pkg_path_in_dir(char path[PKG_PATH_MAX], + const dir_rec_t* dir, + const char* pkgname, + const char* postfix) +{ + const size_t postfix_len = strlen(postfix); + + const size_t pkgname_len = strlen(pkgname); + if (pkgname_len > PKG_NAME_MAX) { + return -1; + } + + if (is_valid_package_name(pkgname) < 0) { + return -1; + } + + if ((pkgname_len + dir->len + postfix_len) >= PKG_PATH_MAX) { + return -1; + } + + char *dst = path; + size_t dst_size = PKG_PATH_MAX; + + if (append_and_increment(&dst, dir->path, &dst_size) < 0 + || append_and_increment(&dst, pkgname, &dst_size) < 0 + || append_and_increment(&dst, postfix, &dst_size) < 0) { + LOGE("Error building APK path"); + return -1; + } + + return 0; +} + +/** + * Create the package path name for a given package name with a postfix for + * a certain persona. Returns 0 on success, and -1 on failure. + */ int create_pkg_path(char path[PKG_PATH_MAX], - const char *prefix, const char *pkgname, - const char *postfix) + const char *postfix, + uid_t persona) { - int len; - const char *x; + size_t uid_len; + char* persona_prefix; + if (persona == 0) { + persona_prefix = PRIMARY_USER_PREFIX; + uid_len = 0; + } else { + persona_prefix = SECONDARY_USER_PREFIX; + uid_len = snprintf(NULL, 0, "%d", persona); + } + + const size_t prefix_len = android_data_dir.len + strlen(persona_prefix) + uid_len + 1 /*slash*/; + char prefix[prefix_len + 1]; - len = strlen(pkgname); - if (len > PKG_NAME_MAX) { + char *dst = prefix; + size_t dst_size = sizeof(prefix); + + if (append_and_increment(&dst, android_data_dir.path, &dst_size) < 0 + || append_and_increment(&dst, persona_prefix, &dst_size) < 0) { + LOGE("Error building prefix for APK path"); return -1; } - if ((len + strlen(prefix) + strlen(postfix)) >= PKG_PATH_MAX) { - return -1; + + if (persona != 0) { + int ret = snprintf(dst, dst_size, "%d/", persona); + if (ret < 0 || (size_t) ret != uid_len + 1) { + LOGW("Error appending UID to APK path"); + return -1; + } } - x = pkgname; + dir_rec_t dir; + dir.path = prefix; + dir.len = prefix_len; + + return create_pkg_path_in_dir(path, &dir, pkgname, postfix); +} + +/** + * Checks whether the package name is valid. Returns -1 on error and + * 0 on success. + */ +int is_valid_package_name(const char* pkgname) { + const char *x = pkgname; int alpha = -1; + while (*x) { if (isalnum(*x) || (*x == '_')) { /* alphanumeric or underscore are fine */ @@ -47,13 +116,15 @@ int create_pkg_path(char path[PKG_PATH_MAX], /* Suffix -X is fine to let versioning of packages. But whatever follows should be alphanumeric.*/ alpha = 1; - }else { + } else { /* anything not A-Z, a-z, 0-9, _, or . is invalid */ LOGE("invalid package name '%s'\n", pkgname); return -1; } + x++; } + if (alpha == 1) { // Skip current character x++; @@ -66,7 +137,6 @@ int create_pkg_path(char path[PKG_PATH_MAX], } } - sprintf(path, "%s%s%s", prefix, pkgname, postfix); return 0; } @@ -171,3 +241,170 @@ int delete_dir_contents_fd(int dfd, const char *name) closedir(d); return res; } + +/** + * Checks whether a path points to a system app (.apk file). Returns 0 + * if it is a system app or -1 if it is not. + */ +int validate_system_app_path(const char* path) { + size_t i; + + for (i = 0; i < android_system_dirs.count; i++) { + const size_t dir_len = android_system_dirs.dirs[i].len; + if (!strncmp(path, android_system_dirs.dirs[i].path, dir_len)) { + if (path[dir_len] == '.' || strchr(path + dir_len, '/') != NULL) { + LOGE("invalid system apk path '%s' (trickery)\n", path); + return -1; + } + return 0; + } + } + + return -1; +} + +/** + * Get the contents of a environment variable that contains a path. Caller + * owns the string that is inserted into the directory record. Returns + * 0 on success and -1 on error. + */ +int get_path_from_env(dir_rec_t* rec, const char* var) { + const char* path = getenv(var); + int ret = get_path_from_string(rec, path); + if (ret < 0) { + LOGW("Problem finding value for environment variable %s\n", var); + } + return ret; +} + +/** + * Puts the string into the record as a directory. Appends '/' to the end + * of all paths. Caller owns the string that is inserted into the directory + * record. A null value will result in an error. + * + * Returns 0 on success and -1 on error. + */ +int get_path_from_string(dir_rec_t* rec, const char* path) { + if (path == NULL) { + return -1; + } else { + const size_t path_len = strlen(path); + if (path_len <= 0) { + return -1; + } + + // Make sure path is absolute. + if (path[0] != '/') { + return -1; + } + + if (path[path_len - 1] == '/') { + // Path ends with a forward slash. Make our own copy. + + rec->path = strdup(path); + if (rec->path == NULL) { + return -1; + } + + rec->len = path_len; + } else { + // Path does not end with a slash. Generate a new string. + char *dst; + + // Add space for slash and terminating null. + size_t dst_size = path_len + 2; + + rec->path = malloc(dst_size); + if (rec->path == NULL) { + return -1; + } + + dst = rec->path; + + if (append_and_increment(&dst, path, &dst_size) < 0 + || append_and_increment(&dst, "/", &dst_size)) { + LOGE("Error canonicalizing path"); + return -1; + } + + rec->len = dst - rec->path; + } + } + return 0; +} + +int copy_and_append(dir_rec_t* dst, const dir_rec_t* src, const char* suffix) { + dst->len = src->len + strlen(suffix); + const size_t dstSize = dst->len + 1; + dst->path = (char*) malloc(dstSize); + + if (dst->path == NULL + || snprintf(dst->path, dstSize, "%s%s", src->path, suffix) + != (ssize_t) dst->len) { + LOGE("Could not allocate memory to hold appended path; aborting\n"); + return -1; + } + + return 0; +} + +/** + * Check whether path points to a valid path for an APK file. An ASEC + * directory is allowed to have one level of subdirectory names. Returns -1 + * when an invalid path is encountered and 0 when a valid path is encountered. + */ +int validate_apk_path(const char *path) +{ + int allowsubdir = 0; + char *subdir = NULL; + size_t dir_len; + size_t path_len; + + if (!strncmp(path, android_app_dir.path, android_app_dir.len)) { + dir_len = android_app_dir.len; + } else if (!strncmp(path, android_app_private_dir.path, android_app_private_dir.len)) { + dir_len = android_app_private_dir.len; + } else if (!strncmp(path, android_asec_dir.path, android_asec_dir.len)) { + dir_len = android_asec_dir.len; + allowsubdir = 1; + } else { + LOGE("invalid apk path '%s' (bad prefix)\n", path); + return -1; + } + + path_len = strlen(path); + + /* + * Only allow the path to have a subdirectory if it's been marked as being allowed. + */ + if ((subdir = strchr(path + dir_len, '/')) != NULL) { + ++subdir; + if (!allowsubdir + || (path_len > (size_t) (subdir - path) && (strchr(subdir, '/') != NULL))) { + LOGE("invalid apk path '%s' (subdir?)\n", path); + return -1; + } + } + + /* + * Directories can't have a period directly after the directory markers + * to prevent ".." + */ + if (path[dir_len] == '.' + || (subdir != NULL && ((*subdir == '.') || (strchr(subdir, '/') != NULL)))) { + LOGE("invalid apk path '%s' (trickery)\n", path); + return -1; + } + + return 0; +} + +int append_and_increment(char** dst, const char* src, size_t* dst_size) { + ssize_t ret = strlcpy(*dst, src, *dst_size); + if (ret < 0 || (size_t) ret >= *dst_size) { + return -1; + } + *dst += ret; + *dst_size -= ret; + return 0; +} |