X-Git-Url: http://git.archive.openwrt.org/?p=project%2Fuci.git;a=blobdiff_plain;f=util.c;h=4713c74befe6eab5935c2d6be48033c95f64204a;hp=bcf65aa106e82cb6c41c9b9850027a9185f97383;hb=031b620e1f3a16078da45ce00352508764902786;hpb=65e2c3559b451315935f9483c5f4e59d63441e54 diff --git a/util.c b/util.c index bcf65aa..4713c74 100644 --- a/util.c +++ b/util.c @@ -59,19 +59,32 @@ static char *uci_strdup(struct uci_context *ctx, const char *str) return ptr; } -static bool uci_validate_name(const char *str) +/* + * validate strings for names and types, reject special characters + * for names, only alphanum and _ is allowed (shell compatibility) + * for types, we allow more characters + */ +static bool uci_validate_str(const char *str, bool name) { if (!*str) return false; while (*str) { - if (!isalnum(*str) && (*str != '_')) - return false; + char c = *str; + if (!isalnum(c) && c != '_') { + if (name || (c < 33) || (c > 126)) + return false; + } str++; } return true; } +static inline bool uci_validate_name(const char *str) +{ + return uci_validate_str(str, true); +} + static void uci_alloc_parse_context(struct uci_context *ctx) { ctx->pctx = (struct uci_parse_context *) uci_malloc(ctx, sizeof(struct uci_parse_context)); @@ -176,6 +189,191 @@ static void uci_getln(struct uci_context *ctx, int offset) } while (1); } +/* + * parse a character escaped by '\' + * returns true if the escaped character is to be parsed + * returns false if the escaped character is to be ignored + */ +static inline bool parse_backslash(struct uci_context *ctx, char **str) +{ + /* skip backslash */ + *str += 1; + + /* undecoded backslash at the end of line, fetch the next line */ + if (!**str) { + *str += 1; + uci_getln(ctx, *str - ctx->pctx->buf); + return false; + } + + /* FIXME: decode escaped char, necessary? */ + return true; +} + +/* + * move the string pointer forward until a non-whitespace character or + * EOL is reached + */ +static void skip_whitespace(struct uci_context *ctx, char **str) +{ +restart: + while (**str && isspace(**str)) + *str += 1; + + if (**str == '\\') { + if (!parse_backslash(ctx, str)) + goto restart; + } +} + +static inline void addc(char **dest, char **src) +{ + **dest = **src; + *dest += 1; + *src += 1; +} + +/* + * parse a double quoted string argument from the command line + */ +static void parse_double_quote(struct uci_context *ctx, char **str, char **target) +{ + char c; + + /* skip quote character */ + *str += 1; + + while ((c = **str)) { + switch(c) { + case '"': + **target = 0; + *str += 1; + return; + case '\\': + if (!parse_backslash(ctx, str)) + continue; + /* fall through */ + default: + addc(target, str); + break; + } + } + uci_parse_error(ctx, *str, "unterminated \""); +} + +/* + * parse a single quoted string argument from the command line + */ +static void parse_single_quote(struct uci_context *ctx, char **str, char **target) +{ + char c; + /* skip quote character */ + *str += 1; + + while ((c = **str)) { + switch(c) { + case '\'': + **target = 0; + *str += 1; + return; + default: + addc(target, str); + } + } + uci_parse_error(ctx, *str, "unterminated '"); +} + +/* + * parse a string from the command line and detect the quoting style + */ +static void parse_str(struct uci_context *ctx, char **str, char **target) +{ + do { + switch(**str) { + case '\'': + parse_single_quote(ctx, str, target); + break; + case '"': + parse_double_quote(ctx, str, target); + break; + case '#': + **str = 0; + /* fall through */ + case 0: + goto done; + case '\\': + if (!parse_backslash(ctx, str)) + continue; + /* fall through */ + default: + addc(target, str); + break; + } + } while (**str && !isspace(**str)); +done: + + /* + * if the string was unquoted and we've stopped at a whitespace + * character, skip to the next one, because the whitespace will + * be overwritten by a null byte here + */ + if (**str) + *str += 1; + + /* terminate the parsed string */ + **target = 0; +} + +/* + * extract the next argument from the command line + */ +static char *next_arg(struct uci_context *ctx, char **str, bool required, bool name) +{ + char *val; + char *ptr; + + val = ptr = *str; + skip_whitespace(ctx, str); + parse_str(ctx, str, &ptr); + if (!*val) { + if (required) + uci_parse_error(ctx, *str, "insufficient arguments"); + goto done; + } + + if (name && !uci_validate_name(val)) + uci_parse_error(ctx, val, "invalid character in field"); + +done: + return val; +} + +int uci_parse_argument(struct uci_context *ctx, FILE *stream, char **str, char **result) +{ + UCI_HANDLE_ERR(ctx); + UCI_ASSERT(ctx, str != NULL); + UCI_ASSERT(ctx, result != NULL); + + if (ctx->pctx) { + if (ctx->pctx->file != stream) { + ctx->internal = true; + uci_cleanup(ctx); + } + } else { + uci_alloc_parse_context(ctx); + ctx->pctx->file = stream; + } + if (!*str) { + uci_getln(ctx, 0); + *str = ctx->pctx->buf; + } + + *result = next_arg(ctx, str, false, false); + + return 0; +} + + /* * open a stream and go to the right position *