laforge has submitted this change. ( https://gerrit.osmocom.org/c/libosmocore/+/16159 )
Change subject: fix osmo_escape_str_c() and osmo_quote_str_c() ...................................................................... fix osmo_escape_str_c() and osmo_quote_str_c() The osmo_escape_str_c() and osmo_quote_str_c() functions return truncated results when characters need escaping. For example: osmo_quote_str_c(NULL, "foo"); --> "foo" osmo_quote_str_c(NULL, "foo\n"); --> "foo\n osmo_quote_str_c(NULL, "foo\tbar\t\n"); --> "foo\tbar\t Implement these _c variants using OSMO_NAME_C_IMPL() to always allocate sufficient memory. However, current osmo_escape_str_buf2() and osmo_quote_str_buf2() fail to return the required buffer size (even though that information is readily avaiable), so these don't qualify for accurate use of OSMO_NAME_C_IMPL(). Hence, move the implementations of osmo_escape_str and osmo_quote_str to an internal static function that returns the characters needed, so that all dynamically allocating implementations can return un-truncated results. Of course, external callers would also benefit from escape/quote API that accurately returns the amount of characters needed, but I am not changing public API in this patch, on purpose, ... yet. Change-Id: I16c08eced41bf1b7acf6e95f658068ace99ca4c8 --- M src/utils.c 1 file changed, 49 insertions(+), 31 deletions(-) Approvals: laforge: Looks good to me, approved pespin: Looks good to me, but someone else must approve Jenkins Builder: Verified diff --git a/src/utils.c b/src/utils.c index 6fc2ee6..904f6e4 100644 --- a/src/utils.c +++ b/src/utils.c @@ -668,13 +668,15 @@ } /*! Return the string with all non-printable characters escaped. + * This internal function is the implementation for all osmo_escape_str* and osmo_quote_str* API versions. + * It provides a return value of characters-needed, to allow producing un-truncated strings in all cases. * \param[out] buf string buffer to write escaped characters to. * \param[in] bufsize sizeof(buf). * \param[in] str A string that may contain any characters. * \param[in] in_len Pass -1 to print until nul char, or >= 0 to force a length (also past nul chars). - * \return The output buffer (buf). + * \return Number of characters that would be written if bufsize were large enough excluding '\0' (like snprintf()). */ -char *osmo_escape_str_buf2(char *buf, size_t bufsize, const char *str, int in_len) +static size_t _osmo_escape_str_buf(char *buf, size_t bufsize, const char *str, int in_len) { struct osmo_strbuf sb = { .buf = buf, .len = bufsize }; int in_pos = 0; @@ -729,6 +731,19 @@ } done: + return sb.chars_needed; +} + +/*! Return the string with all non-printable characters escaped. + * \param[out] buf string buffer to write escaped characters to. + * \param[in] bufsize sizeof(buf). + * \param[in] str A string that may contain any characters. + * \param[in] in_len Pass -1 to print until nul char, or >= 0 to force a length (also past nul chars). + * \return The output buffer (buf). + */ +char *osmo_escape_str_buf2(char *buf, size_t bufsize, const char *str, int in_len) +{ + _osmo_escape_str_buf(buf, bufsize, str, in_len); return buf; } @@ -750,10 +765,31 @@ */ char *osmo_escape_str_c(const void *ctx, const char *str, int in_len) { - char *buf = talloc_size(ctx, in_len+1); - if (!buf) - return NULL; - return osmo_escape_str_buf2(buf, in_len+1, str, in_len); + /* The string will be at least as long as in_len, but some characters might need escaping. + * These extra bytes should catch most usual escaping situations, avoiding a second run in OSMO_NAME_C_IMPL. */ + OSMO_NAME_C_IMPL(ctx, in_len + 16, "ERROR", _osmo_escape_str_buf, str, in_len); +} + +/*! Return a quoted and escaped representation of the string. + * This internal function is the implementation for all osmo_quote_str* API versions. + * It provides a return value of characters-needed, to allow producing un-truncated strings in all cases. + * \param[out] buf string buffer to write escaped characters to. + * \param[in] bufsize sizeof(buf). + * \param[in] str A string that may contain any characters. + * \param[in] in_len Pass -1 to print until nul char, or >= 0 to force a length (also past nul chars). + * \return Number of characters that would be written if bufsize were large enough excluding '\0' (like snprintf()). + */ +static size_t _osmo_quote_str_buf(char *buf, size_t bufsize, const char *str, int in_len) +{ + struct osmo_strbuf sb = { .buf = buf, .len = bufsize }; + if (!str) + OSMO_STRBUF_PRINTF(sb, "NULL"); + else { + OSMO_STRBUF_PRINTF(sb, "\""); + OSMO_STRBUF_APPEND(sb, _osmo_escape_str_buf, str, in_len); + OSMO_STRBUF_PRINTF(sb, "\""); + } + return sb.chars_needed; } /*! Like osmo_escape_str_buf2(), but returns double-quotes around a string, or "NULL" for a NULL string. @@ -767,14 +803,7 @@ */ char *osmo_quote_str_buf2(char *buf, size_t bufsize, const char *str, int in_len) { - struct osmo_strbuf sb = { .buf = buf, .len = bufsize }; - if (!str) - OSMO_STRBUF_PRINTF(sb, "NULL"); - else { - OSMO_STRBUF_PRINTF(sb, "\""); - OSMO_STRBUF_APPEND_NOLEN(sb, osmo_escape_str_buf2, str, in_len); - OSMO_STRBUF_PRINTF(sb, "\""); - } + _osmo_quote_str_buf(buf, bufsize, str, in_len); return buf; } @@ -792,7 +821,7 @@ return "NULL"; if (!buf || !bufsize) return "(error)"; - osmo_quote_str_buf2(buf, bufsize, str, in_len); + _osmo_quote_str_buf(buf, bufsize, str, in_len); return buf; } @@ -804,7 +833,8 @@ */ const char *osmo_quote_str(const char *str, int in_len) { - return osmo_quote_str_buf(str, in_len, namebuf, sizeof(namebuf)); + _osmo_quote_str_buf(namebuf, sizeof(namebuf), str, in_len); + return namebuf; } /*! Like osmo_quote_str_buf() but returns the result in a dynamically-allocated buffer. @@ -814,21 +844,9 @@ */ char *osmo_quote_str_c(const void *ctx, const char *str, int in_len) { - size_t len = in_len == -1 ? strlen(str) : in_len; - char *buf; - - /* account for two quote characters + terminating NUL */ - len += 3; - - /* some minimum length for things like "NULL" or "(error)" */ - if (len < 32) - len = 32; - - buf = talloc_size(ctx, len); - if (!buf) - return NULL; - - return osmo_quote_str_buf2(buf, len, str, in_len); + /* The string will be at least as long as in_len, but some characters might need escaping. + * These extra bytes should catch most usual escaping situations, avoiding a second run in OSMO_NAME_C_IMPL. */ + OSMO_NAME_C_IMPL(ctx, in_len + 16, "ERROR", _osmo_quote_str_buf, str, in_len); } /*! perform an integer square root operation on unsigned 32bit integer. -- To view, visit https://gerrit.osmocom.org/c/libosmocore/+/16159 To unsubscribe, or for help writing mail filters, visit https://gerrit.osmocom.org/settings Gerrit-Project: libosmocore Gerrit-Branch: master Gerrit-Change-Id: I16c08eced41bf1b7acf6e95f658068ace99ca4c8 Gerrit-Change-Number: 16159 Gerrit-PatchSet: 4 Gerrit-Owner: neels <nhofm...@sysmocom.de> Gerrit-Reviewer: Jenkins Builder Gerrit-Reviewer: laforge <lafo...@osmocom.org> Gerrit-Reviewer: pespin <pes...@sysmocom.de> Gerrit-MessageType: merged