diff --git a/Documentation/config/sideband.txt b/Documentation/config/sideband.txt index b55c73726f..2bf0426284 100644 --- a/Documentation/config/sideband.txt +++ b/Documentation/config/sideband.txt @@ -2,13 +2,20 @@ sideband.allowControlCharacters:: By default, control characters that are delivered via the sideband are masked, except ANSI color sequences. This prevents potentially unwanted ANSI escape sequences from being sent to the terminal. Use - this config setting to override this behavior: + this config setting to override this behavior (the value can be + a comma-separated list of the following keywords): + -- `default`:: `color`:: Allow ANSI color sequences, line feeds and horizontal tabs, but mask all other control characters. This is the default. + `cursor:`: + Allow control sequences that move the cursor. This is + disabled by default. + `erase`:: + Allow control sequences that erase charactrs. This is + disabled by default. `false`:: Mask all control characters other than line feeds and horizontal tabs. diff --git a/sideband.c b/sideband.c index f4bcdcaf9b..a8568b8b64 100644 --- a/sideband.c +++ b/sideband.c @@ -28,9 +28,43 @@ static struct keyword_entry keywords[] = { static enum { ALLOW_NO_CONTROL_CHARACTERS = 0, ALLOW_ANSI_COLOR_SEQUENCES = 1<<0, + ALLOW_ANSI_CURSOR_MOVEMENTS = 1<<1, + ALLOW_ANSI_ERASE = 1<<2, ALLOW_DEFAULT_ANSI_SEQUENCES = ALLOW_ANSI_COLOR_SEQUENCES, - ALLOW_ALL_CONTROL_CHARACTERS = 1<<1, -} allow_control_characters = ALLOW_ANSI_COLOR_SEQUENCES; + ALLOW_ALL_CONTROL_CHARACTERS = 1<<3, +} allow_control_characters = ALLOW_DEFAULT_ANSI_SEQUENCES; + +static inline int skip_prefix_in_csv(const char *value, const char *prefix, + const char **out) +{ + if (!skip_prefix(value, prefix, &value) || + (*value && *value != ',')) + return 0; + *out = value + !!*value; + return 1; +} + +static void parse_allow_control_characters(const char *value) +{ + allow_control_characters = ALLOW_NO_CONTROL_CHARACTERS; + while (*value) { + if (skip_prefix_in_csv(value, "default", &value)) + allow_control_characters |= ALLOW_DEFAULT_ANSI_SEQUENCES; + else if (skip_prefix_in_csv(value, "color", &value)) + allow_control_characters |= ALLOW_ANSI_COLOR_SEQUENCES; + else if (skip_prefix_in_csv(value, "cursor", &value)) + allow_control_characters |= ALLOW_ANSI_CURSOR_MOVEMENTS; + else if (skip_prefix_in_csv(value, "erase", &value)) + allow_control_characters |= ALLOW_ANSI_ERASE; + else if (skip_prefix_in_csv(value, "true", &value)) + allow_control_characters = ALLOW_ALL_CONTROL_CHARACTERS; + else if (skip_prefix_in_csv(value, "false", &value)) + allow_control_characters = ALLOW_NO_CONTROL_CHARACTERS; + else + warning(_("unrecognized value for `sideband." + "allowControlCharacters`: '%s'"), value); + } +} /* Returns a color setting (GIT_COLOR_NEVER, etc). */ static int use_sideband_colors(void) @@ -54,13 +88,8 @@ static int use_sideband_colors(void) if (git_config_get_string_tmp("sideband.allowcontrolcharacters", &value)) ; /* huh? `get_maybe_bool()` returned -1 */ - else if (!strcmp(value, "default")) - allow_control_characters = ALLOW_DEFAULT_ANSI_SEQUENCES; - else if (!strcmp(value, "color")) - allow_control_characters = ALLOW_ANSI_COLOR_SEQUENCES; else - warning(_("unrecognized value for `sideband." - "allowControlCharacters`: '%s'"), value); + parse_allow_control_characters(value); break; default: break; /* not configured */ @@ -93,7 +122,7 @@ void list_config_color_sideband_slots(struct string_list *list, const char *pref list_config_item(list, prefix, keywords[i].keyword); } -static int handle_ansi_color_sequence(struct strbuf *dest, const char *src, int n) +static int handle_ansi_sequence(struct strbuf *dest, const char *src, int n) { int i; @@ -105,14 +134,47 @@ static int handle_ansi_color_sequence(struct strbuf *dest, const char *src, int * These are part of the Select Graphic Rendition sequences which * contain more than just color sequences, for more details see * https://en.wikipedia.org/wiki/ANSI_escape_code#SGR. + * + * The cursor movement sequences are: + * + * ESC [ n A - Cursor up n lines (CUU) + * ESC [ n B - Cursor down n lines (CUD) + * ESC [ n C - Cursor forward n columns (CUF) + * ESC [ n D - Cursor back n columns (CUB) + * ESC [ n E - Cursor next line, beginning (CNL) + * ESC [ n F - Cursor previous line, beginning (CPL) + * ESC [ n G - Cursor to column n (CHA) + * ESC [ n ; m H - Cursor position (row n, col m) (CUP) + * ESC [ n ; m f - Same as H (HVP) + * + * The sequences to erase characters are: + * + * + * ESC [ 0 J - Clear from cursor to end of screen (ED) + * ESC [ 1 J - Clear from cursor to beginning of screen (ED) + * ESC [ 2 J - Clear entire screen (ED) + * ESC [ 3 J - Clear entire screen + scrollback (ED) - xterm extension + * ESC [ 0 K - Clear from cursor to end of line (EL) + * ESC [ 1 K - Clear from cursor to beginning of line (EL) + * ESC [ 2 K - Clear entire line (EL) + * ESC [ n M - Delete n lines (DL) + * ESC [ n P - Delete n characters (DCH) + * ESC [ n X - Erase n characters (ECH) + * + * For a comprehensive list of common ANSI Escape sequences, see + * https://www.xfree86.org/current/ctlseqs.html */ - if (allow_control_characters != ALLOW_ANSI_COLOR_SEQUENCES || - n < 3 || src[0] != '\x1b' || src[1] != '[') + if (n < 3 || src[0] != '\x1b' || src[1] != '[') return 0; for (i = 2; i < n; i++) { - if (src[i] == 'm') { + if (((allow_control_characters & ALLOW_ANSI_COLOR_SEQUENCES) && + src[i] == 'm') || + ((allow_control_characters & ALLOW_ANSI_CURSOR_MOVEMENTS) && + strchr("ABCDEFGHf", src[i])) || + ((allow_control_characters & ALLOW_ANSI_ERASE) && + strchr("JKMPX", src[i]))) { strbuf_add(dest, src, i + 1); return i; } @@ -127,7 +189,7 @@ static void strbuf_add_sanitized(struct strbuf *dest, const char *src, int n) { int i; - if (allow_control_characters == ALLOW_ALL_CONTROL_CHARACTERS) { + if ((allow_control_characters & ALLOW_ALL_CONTROL_CHARACTERS)) { strbuf_add(dest, src, n); return; } @@ -136,7 +198,8 @@ static void strbuf_add_sanitized(struct strbuf *dest, const char *src, int n) for (; n && *src; src++, n--) { if (!iscntrl(*src) || *src == '\t' || *src == '\n') { strbuf_addch(dest, *src); - } else if ((i = handle_ansi_color_sequence(dest, src, n))) { + } else if (allow_control_characters != ALLOW_NO_CONTROL_CHARACTERS && + (i = handle_ansi_sequence(dest, src, n))) { src += i; n -= i; } else { diff --git a/t/t5409-colorize-remote-messages.sh b/t/t5409-colorize-remote-messages.sh index f34977b332..c3e4e14362 100755 --- a/t/t5409-colorize-remote-messages.sh +++ b/t/t5409-colorize-remote-messages.sh @@ -129,4 +129,42 @@ test_expect_success 'disallow (color) control sequences in sideband' ' test_file_not_empty actual ' +test_decode_csi() { + awk '{ + while (match($0, /\033/) != 0) { + printf "%sCSI ", substr($0, 1, RSTART-1); + $0 = substr($0, RSTART + RLENGTH, length($0) - RSTART - RLENGTH + 1); + } + print + }' +} + +test_expect_success 'control sequences in sideband allowed by default' ' + write_script .git/color-me-surprised <<-\EOF && + printf "error: \\033[31mcolor\\033[m\\033[Goverwrite\\033[Gerase\\033[K\\033?25l\\n" >&2 + exec "$@" + EOF + test_config_global uploadPack.packObjectsHook ./color-me-surprised && + test_commit need-at-least-one-commit-at-least && + + rm -rf throw-away && + git clone --no-local . throw-away 2>stderr && + test_decode_color color-decoded && + test_decode_csi decoded && + test_grep ! "CSI \\[K" decoded && + test_grep ! "CSI \\[G" decoded && + test_grep "\\^\\[?25l" decoded && + + rm -rf throw-away && + git -c sideband.allowControlCharacters=erase,cursor,color \ + clone --no-local . throw-away 2>stderr && + test_decode_color color-decoded && + test_decode_csi decoded && + test_grep "RED" decoded && + test_grep "CSI \\[K" decoded && + test_grep "CSI \\[G" decoded && + test_grep ! "\\^\\[\\[K" decoded && + test_grep ! "\\^\\[\\[G" decoded +' + test_done