From aa449c927d1d84092f9654e45ab9f68847e81226 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Sat, 28 Jul 2018 12:13:58 +0200 Subject: [PATCH] hush: make "set -x" output don't redirectable when fd#2 redirected function old new delta x_mode_print_optionally_squoted - 120 +120 x_mode_flush - 68 +68 save_fd_on_redirect 208 243 +35 x_mode_prefix - 27 +27 x_mode_addblock - 23 +23 x_mode_addchr - 17 +17 dump_cmd_in_x_mode 110 85 -25 run_pipe 1919 1890 -29 print_optionally_squoted 145 - -145 ------------------------------------------------------------------------------ (add/remove: 5/1 grow/shrink: 1/2 up/down: 290/-199) Total: 91 bytes Signed-off-by: Denys Vlasenko --- shell/hush.c | 129 +++++++++++++++++++++++++++++++++------------------ 1 file changed, 84 insertions(+), 45 deletions(-) diff --git a/shell/hush.c b/shell/hush.c index ac8467fb4..9676819fa 100644 --- a/shell/hush.c +++ b/shell/hush.c @@ -954,9 +954,6 @@ struct globals { unsigned func_nest_level; /* solely to prevent "local v" in non-functions */ # endif struct function *top_func; -#endif -#if ENABLE_HUSH_MODE_X - unsigned x_mode_depth; #endif /* Signal and trap handling */ #if ENABLE_HUSH_FAST @@ -993,6 +990,15 @@ struct globals { #if ENABLE_HUSH_MEMLEAK unsigned long memleak_value; #endif +#if ENABLE_HUSH_MODE_X + unsigned x_mode_depth; + /* "set -x" output should not be redirectable with subsequent 2>FILE. + * We dup fd#2 to x_mode_fd when "set -x" is executed, and use it + * for all subsequent output. + */ + int x_mode_fd; + o_string x_mode_buf; +#endif #if HUSH_DEBUG int debug_indent; #endif @@ -1660,6 +1666,12 @@ static int move_HFILEs_on_redirect(int fd, int avoid_fd) } fl = fl->next_hfile; } +#if ENABLE_HUSH_MODE_X + if (G.x_mode_fd > 0 && fd == G.x_mode_fd) { + G.x_mode_fd = xdup_CLOEXEC_and_close(fd, avoid_fd); + return 1; /* "found and moved" */ + } +#endif return 0; /* "not in the list" */ } #if ENABLE_FEATURE_SH_STANDALONE && BB_MMU @@ -2903,6 +2915,11 @@ static void o_addstr(o_string *o, const char *str) o_addblock(o, str, strlen(str)); } +static void o_addstr_with_NUL(o_string *o, const char *str) +{ + o_addblock(o, str, strlen(str) + 1); +} + #if !BB_MMU static void nommu_addchr(o_string *o, int ch) { @@ -2913,10 +2930,36 @@ static void nommu_addchr(o_string *o, int ch) # define nommu_addchr(o, str) ((void)0) #endif -static void o_addstr_with_NUL(o_string *o, const char *str) +#if ENABLE_HUSH_MODE_X +static void x_mode_addchr(int ch) { - o_addblock(o, str, strlen(str) + 1); + o_addchr(&G.x_mode_buf, ch); } +static void x_mode_addstr(const char *str) +{ + o_addstr(&G.x_mode_buf, str); +} +static void x_mode_addblock(const char *str, int len) +{ + o_addblock(&G.x_mode_buf, str, len); +} +static void x_mode_prefix(void) +{ + int n = G.x_mode_depth; + do x_mode_addchr('+'); while (--n >= 0); +} +static void x_mode_flush(void) +{ + int len = G.x_mode_buf.length; + if (len <= 0) + return; + if (G.x_mode_fd > 0) { + G.x_mode_buf.data[len] = '\n'; + full_write(G.x_mode_fd, G.x_mode_buf.data, len + 1); + } + G.x_mode_buf.length = 0; +} +#endif /* * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side. @@ -8030,31 +8073,26 @@ static void execvp_or_die(char **argv) } #if ENABLE_HUSH_MODE_X -static void print_optionally_squoted(FILE *fp, const char *str) +static void x_mode_print_optionally_squoted(const char *str) { unsigned len; const char *cp; cp = str; - if (str[0] != '{' && str[0] != '(') for (;;) { - if (!*cp) { - /* string has no special chars */ - fputs(str, fp); - return; - } - if (*cp == '\\') break; - if (*cp == '\'') break; - if (*cp == '"') break; - if (*cp == '$') break; - if (*cp == '!') break; - if (*cp == '*') break; - if (*cp == '[') break; - if (*cp == ']') break; -#if ENABLE_HUSH_TICK - if (*cp == '`') break; -#endif - if (isspace(*cp)) break; - cp++; + + /* the set of chars which-cause-string-to-be-squoted mimics bash */ + /* test a char with: bash -c 'set -x; echo "CH"' */ + if (str[strcspn(str, "\\\"'`$(){}[]<>;#&|~*?!^" + " " "\001\002\003\004\005\006\007" + "\010\011\012\013\014\015\016\017" + "\020\021\022\023\024\025\026\027" + "\030\031\032\033\034\035\036\037" + ) + ] == '\0' + ) { + /* string has no special chars */ + x_mode_addstr(str); + return; } cp = str; @@ -8062,13 +8100,16 @@ static void print_optionally_squoted(FILE *fp, const char *str) /* print '....' up to EOL or first squote */ len = (int)(strchrnul(cp, '\'') - cp); if (len != 0) { - fprintf(fp, "'%.*s'", len, cp); + x_mode_addchr('\''); + x_mode_addblock(cp, len); + x_mode_addchr('\''); cp += len; } if (*cp == '\0') break; /* string contains squote(s), print them as \' */ - fprintf(fp, "\\'"); + x_mode_addchr('\\'); + x_mode_addchr('\''); cp++; } } @@ -8078,19 +8119,19 @@ static void dump_cmd_in_x_mode(char **argv) unsigned n; /* "+[+++...][ cmd...]\n\0" */ - n = G.x_mode_depth; - do bb_putchar_stderr('+'); while ((int)(--n) >= 0); + x_mode_prefix(); n = 0; while (argv[n]) { - if (argv[n][0] == '\0') - fputs(" ''", stderr); - else { - bb_putchar_stderr(' '); - print_optionally_squoted(stderr, argv[n]); + x_mode_addchr(' '); + if (argv[n][0] == '\0') { + x_mode_addchr('\''); + x_mode_addchr('\''); + } else { + x_mode_print_optionally_squoted(argv[n]); } n++; } - bb_putchar_stderr('\n'); + x_mode_flush(); } } #else @@ -8885,17 +8926,14 @@ static NOINLINE int run_pipe(struct pipe *pi) #if ENABLE_HUSH_MODE_X if (G_x_mode) { char *eq; - if (i == 0) { - unsigned n = G.x_mode_depth; - do - bb_putchar_stderr('+'); - while ((int)(--n) >= 0); - } + if (i == 0) + x_mode_prefix(); + x_mode_addchr(' '); eq = strchrnul(p, '='); - fprintf(stderr, " %.*s=", (int)(eq - p), p); - if (*eq) - print_optionally_squoted(stderr, eq + 1); - bb_putchar_stderr('\n'); + if (*eq) eq++; + x_mode_addblock(p, (eq - p)); + x_mode_print_optionally_squoted(eq); + x_mode_flush(); } #endif debug_printf_env("set shell var:'%s'->'%s'\n", *argv, p); @@ -9691,6 +9729,7 @@ static int set_mode(int state, char mode, const char *o_opt) break; case 'x': IF_HUSH_MODE_X(G_x_mode = state;) + IF_HUSH_MODE_X(if (G.x_mode_fd <= 0) G.x_mode_fd = dup_CLOEXEC(2, 10);) break; case 'o': if (!o_opt) {