commit f0a8664677b8e4a3503172d6e7564da33496be8f Author: Nick Mathewson nickm@torproject.org Date: Thu Dec 6 14:13:29 2018 -0500
Add code to parse K=V lines into config_line_t format.
Closes ticket 28755 --- src/lib/encoding/.may_include | 1 + src/lib/encoding/include.am | 2 + src/lib/encoding/kvline.c | 239 ++++++++++++++++++++++++++++++++++++++++++ src/lib/encoding/kvline.h | 24 +++++ src/test/test_config.c | 78 ++++++++++++++ 5 files changed, 344 insertions(+)
diff --git a/src/lib/encoding/.may_include b/src/lib/encoding/.may_include index 7c2ef3692..c9bf4b178 100644 --- a/src/lib/encoding/.may_include +++ b/src/lib/encoding/.may_include @@ -1,5 +1,6 @@ orconfig.h lib/cc/*.h +lib/container/*.h lib/ctime/*.h lib/encoding/*.h lib/intmath/*.h diff --git a/src/lib/encoding/include.am b/src/lib/encoding/include.am index 2d2aa3988..83e9211b6 100644 --- a/src/lib/encoding/include.am +++ b/src/lib/encoding/include.am @@ -9,6 +9,7 @@ src_lib_libtor_encoding_a_SOURCES = \ src/lib/encoding/confline.c \ src/lib/encoding/cstring.c \ src/lib/encoding/keyval.c \ + src/lib/encoding/kvline.c \ src/lib/encoding/pem.c \ src/lib/encoding/time_fmt.c
@@ -22,5 +23,6 @@ noinst_HEADERS += \ src/lib/encoding/confline.h \ src/lib/encoding/cstring.h \ src/lib/encoding/keyval.h \ + src/lib/encoding/kvline.h \ src/lib/encoding/pem.h \ src/lib/encoding/time_fmt.h diff --git a/src/lib/encoding/kvline.c b/src/lib/encoding/kvline.c new file mode 100644 index 000000000..11ff4f0f9 --- /dev/null +++ b/src/lib/encoding/kvline.c @@ -0,0 +1,239 @@ +/* Copyright (c) 2001 Matej Pfajfar. + * Copyright (c) 2001-2004, Roger Dingledine. + * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. + * Copyright (c) 2007-2018, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +/** + * \file kvline.c + * + * \brief Manipulating lines of key-value pairs. + **/ + +#include "orconfig.h" + +#include "lib/container/smartlist.h" +#include "lib/encoding/confline.h" +#include "lib/encoding/cstring.h" +#include "lib/encoding/kvline.h" +#include "lib/malloc/malloc.h" +#include "lib/string/compat_ctype.h" +#include "lib/string/printf.h" +#include "lib/string/util_string.h" +#include "lib/log/escape.h" +#include "lib/log/util_bug.h" + +#include <stdbool.h> +#include <stddef.h> +#include <string.h> + +/** Return true iff we need to quote and escape the string <b>s</b> to encode + * it. */ +static bool +needs_escape(const char *s, bool as_keyless_val) +{ + if (as_keyless_val && *s == 0) + return true; + + for (; *s; ++s) { + if (*s >= 127 || TOR_ISSPACE(*s) || ! TOR_ISPRINT(*s) || + *s == ''' || *s == '"') { + return true; + } + } + return false; +} + +/** + * Return true iff the key in <b>line</b> is not set. + **/ +static bool +line_has_no_key(const config_line_t *line) +{ + return line->key == NULL || strlen(line->key) == 0; +} + +/** + * Return true iff the all the lines in <b>line</b> can be encoded + * using <b>flags</b>. + **/ +static bool +kvline_can_encode_lines(const config_line_t *line, unsigned flags) +{ + for ( ; line; line = line->next) { + const bool keyless = line_has_no_key(line); + if (keyless) { + if (! (flags & KV_OMIT_KEYS)) { + /* If KV_OMIT_KEYS is not set, we can't encode a line with no key. */ + return false; + } + if (strchr(line->value, '=') && !( flags & KV_QUOTED)) { + /* We can't have a keyless value with = without quoting it. */ + return false; + } + } + + if (needs_escape(line->value, keyless) && ! (flags & KV_QUOTED)) { + /* If KV_QUOTED is false, we can't encode a value that needs quotes. */ + return false; + } + if (line->key && strlen(line->key) && + (needs_escape(line->key, false) || strchr(line->key, '='))) { + /* We can't handle keys that need quoting. */ + return false; + } + } + return true; +} + +/** + * Encode a linked list of lines in <b>line</b> as a series of 'Key=Value' + * pairs, using the provided <b>flags</b> to encode it. Return a newly + * allocated string on success, or NULL on failure. + * + * If KV_QUOTED is set in <b>flags</b>, then all values that contain + * spaces or unusual characters are escaped and quoted. Otherwise, such + * values are not allowed. + * + * If KV_OMIT_KEYS is set in <b>flags</b>, then pairs with empty keys are + * allowed, and are encoded as 'Value'. Otherwise, such pairs are not + * allowed. + */ +char * +kvline_encode(const config_line_t *line, + unsigned flags) +{ + if (!kvline_can_encode_lines(line, flags)) + return NULL; + + smartlist_t *elements = smartlist_new(); + + for (; line; line = line->next) { + + const char *k = ""; + const char *eq = "="; + const char *v = ""; + const bool keyless = line_has_no_key(line); + bool esc = needs_escape(line->value, keyless); + char *tmp = NULL; + + if (! keyless) { + k = line->key; + } else { + eq = ""; + if (strchr(line->value, '=')) { + esc = true; + } + } + + if (esc) { + tmp = esc_for_log(line->value); + v = tmp; + } else { + v = line->value; + } + + smartlist_add_asprintf(elements, "%s%s%s", k, eq, v); + tor_free(tmp); + } + + char *result = smartlist_join_strings(elements, " ", 0, NULL); + + SMARTLIST_FOREACH(elements, char *, cp, tor_free(cp)); + smartlist_free(elements); + + return result; +} + +/** + * Decode a <b>line</b> containing a series of space-separated 'Key=Value' + * pairs, using the provided <b>flags</b> to decode it. Return a newly + * allocated list of pairs on success, or NULL on failure. + * + * If KV_QUOTED is set in <b>flags</b>, then (double-)quoted values are + * allowed. Otherwise, such values are not allowed. + * + * If KV_OMIT_KEYS is set in <b>flags</b>, then values without keys are + * allowed. Otherwise, such values are not allowed. + */ +config_line_t * +kvline_parse(const char *line, unsigned flags) +{ + const char *cp = line, *cplast = NULL; + bool omit_keys = (flags & KV_OMIT_KEYS) != 0; + bool quoted = (flags & KV_QUOTED) != 0; + + config_line_t *result = NULL; + config_line_t **next_line = &result; + + char *key = NULL; + char *val = NULL; + + while (*cp) { + key = val = NULL; + { + size_t idx = strspn(cp, " \t\r\v\n"); + cp += idx; + } + if (BUG(cp == cplast)) { + /* If we didn't parse anything, this code is broken. */ + goto err; // LCOV_EXCL_LINE + } + cplast = cp; + if (! *cp) + break; /* End of string; we're done. */ + + /* Possible formats are K=V, K="V", V, and "V", depending on flags. */ + + /* Find the key. */ + if (*cp != '"') { + size_t idx = strcspn(cp, " \t\r\v\n="); + + if (cp[idx] == '=') { + key = tor_memdup_nulterm(cp, idx); + cp += idx + 1; + } else { + if (!omit_keys) + goto err; + } + } + + if (*cp == '"') { + /* The type is "V". */ + if (!quoted) + goto err; + size_t len=0; + cp = unescape_string(cp, &val, &len); + if (cp == NULL || len != strlen(val)) { + // The string contains a NUL or is badly coded. + goto err; + } + } else { + size_t idx = strcspn(cp, " \t\r\v\n"); + val = tor_memdup_nulterm(cp, idx); + cp += idx; + } + + if (key && strlen(key) == 0) { + /* We don't allow empty keys. */ + goto err; + } + + *next_line = tor_malloc_zero(sizeof(config_line_t)); + (*next_line)->key = key ? key : tor_strdup(""); + (*next_line)->value = val; + next_line = &(*next_line)->next; + key = val = NULL; + } + + if (!kvline_can_encode_lines(result, flags)) { + goto err; + } + return result; + + err: + tor_free(key); + tor_free(val); + config_free_lines(result); + return NULL; +} diff --git a/src/lib/encoding/kvline.h b/src/lib/encoding/kvline.h new file mode 100644 index 000000000..3272cc175 --- /dev/null +++ b/src/lib/encoding/kvline.h @@ -0,0 +1,24 @@ +/* Copyright (c) 2001 Matej Pfajfar. + * Copyright (c) 2001-2004, Roger Dingledine. + * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. + * Copyright (c) 2007-2018, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +/** + * \file kvline.h + * + * \brief Header for kvline.c + **/ + +#ifndef TOR_KVLINE_H +#define TOR_KVLINE_H + +struct config_line_t; + +#define KV_QUOTED (1u<<0) +#define KV_OMIT_KEYS (1u<<1) + +struct config_line_t *kvline_parse(const char *line, unsigned flags); +char *kvline_encode(const struct config_line_t *line, unsigned flags); + +#endif /* !defined(TOR_KVLINE_H) */ diff --git a/src/test/test_config.c b/src/test/test_config.c index dae4d8376..5140c3c1a 100644 --- a/src/test/test_config.c +++ b/src/test/test_config.c @@ -54,6 +54,7 @@ #include "lib/meminfo/meminfo.h" #include "lib/net/gethostname.h" #include "lib/encoding/confline.h" +#include "lib/encoding/kvline.h"
#ifdef HAVE_UNISTD_H #include <unistd.h> @@ -5813,6 +5814,82 @@ test_config_extended_fmt(void *arg) config_free_lines(lines); }
+static void +test_config_kvline_parse(void *arg) +{ + (void)arg; + + config_line_t *lines = NULL; + char *enc = NULL; + + lines = kvline_parse("A=B CD=EF", 0); + tt_assert(lines); + tt_str_op(lines->key, OP_EQ, "A"); + tt_str_op(lines->value, OP_EQ, "B"); + tt_str_op(lines->next->key, OP_EQ, "CD"); + tt_str_op(lines->next->value, OP_EQ, "EF"); + enc = kvline_encode(lines, 0); + tt_str_op(enc, OP_EQ, "A=B CD=EF"); + tor_free(enc); + enc = kvline_encode(lines, KV_QUOTED|KV_OMIT_KEYS); + tt_str_op(enc, OP_EQ, "A=B CD=EF"); + tor_free(enc); + config_free_lines(lines); + + lines = kvline_parse("AB CDE=F", 0); + tt_assert(! lines); + + lines = kvline_parse("AB CDE=F", KV_OMIT_KEYS); + tt_assert(lines); + tt_str_op(lines->key, OP_EQ, ""); + tt_str_op(lines->value, OP_EQ, "AB"); + tt_str_op(lines->next->key, OP_EQ, "CDE"); + tt_str_op(lines->next->value, OP_EQ, "F"); + tt_assert(lines); + enc = kvline_encode(lines, 0); + tt_assert(!enc); + enc = kvline_encode(lines, KV_QUOTED|KV_OMIT_KEYS); + tt_str_op(enc, OP_EQ, "AB CDE=F"); + tor_free(enc); + config_free_lines(lines); + + lines = kvline_parse("AB=C CDE="F G"", 0); + tt_assert(!lines); + + lines = kvline_parse("AB=C CDE="F G" "GHI" ", KV_QUOTED|KV_OMIT_KEYS); + tt_assert(lines); + tt_str_op(lines->key, OP_EQ, "AB"); + tt_str_op(lines->value, OP_EQ, "C"); + tt_str_op(lines->next->key, OP_EQ, "CDE"); + tt_str_op(lines->next->value, OP_EQ, "F G"); + tt_str_op(lines->next->next->key, OP_EQ, ""); + tt_str_op(lines->next->next->value, OP_EQ, "GHI"); + enc = kvline_encode(lines, 0); + tt_assert(!enc); + enc = kvline_encode(lines, KV_QUOTED|KV_OMIT_KEYS); + tt_str_op(enc, OP_EQ, "AB=C CDE="F G" GHI"); + tor_free(enc); + config_free_lines(lines); + + lines = kvline_parse("A"B=C CDE="F" "GHI" ", KV_QUOTED|KV_OMIT_KEYS); + tt_assert(! lines); + + lines = kvline_parse("AB=", KV_QUOTED); + tt_assert(lines); + tt_str_op(lines->key, OP_EQ, "AB"); + tt_str_op(lines->value, OP_EQ, ""); + config_free_lines(lines); + + lines = kvline_parse("AB=", 0); + tt_assert(lines); + tt_str_op(lines->key, OP_EQ, "AB"); + tt_str_op(lines->value, OP_EQ, ""); + + done: + config_free_lines(lines); + tor_free(enc); +} + #define CONFIG_TEST(name, flags) \ { #name, test_config_ ## name, flags, NULL, NULL }
@@ -5864,5 +5941,6 @@ struct testcase_t config_tests[] = { CONFIG_TEST(include_opened_file_list, 0), CONFIG_TEST(compute_max_mem_in_queues, 0), CONFIG_TEST(extended_fmt, 0), + CONFIG_TEST(kvline_parse, 0), END_OF_TESTCASES };