diff options
Diffstat (limited to 'shell/hush.c')
| -rw-r--r-- | shell/hush.c | 274 |
1 files changed, 183 insertions, 91 deletions
diff --git a/shell/hush.c b/shell/hush.c index f34fdd402..e82766093 100644 --- a/shell/hush.c +++ b/shell/hush.c @@ -50,7 +50,7 @@ * * TODOs: * grep for "TODO" and fix (some of them are easy) - * builtins: ulimit, local + * builtins: ulimit * follow IFS rules more precisely, including update semantics * export builtin should be special, its arguments are assignments * and therefore expansion of them should be "one-word" expansion: @@ -593,56 +593,58 @@ struct built_in_command { #endif }; -/* For now, echo and test are unconditionally enabled. - * Maybe make it configurable? */ -static const struct built_in_command bltins[] = { - BLTIN("." , builtin_source , "Run commands in a file"), - BLTIN(":" , builtin_true , "No-op"), - BLTIN("[" , builtin_test , "Test condition"), +static const struct built_in_command bltins1[] = { + BLTIN("." , builtin_source , "Run commands in a file"), + BLTIN(":" , builtin_true , NULL), #if ENABLE_HUSH_JOB - BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"), + BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"), #endif #if ENABLE_HUSH_LOOPS - BLTIN("break" , builtin_break , "Exit from a loop"), + BLTIN("break" , builtin_break , "Exit from a loop"), #endif - BLTIN("cd" , builtin_cd , "Change directory"), + BLTIN("cd" , builtin_cd , "Change directory"), #if ENABLE_HUSH_LOOPS - BLTIN("continue", builtin_continue, "Start new loop iteration"), + BLTIN("continue" , builtin_continue, "Start new loop iteration"), #endif - BLTIN("echo" , builtin_echo , "Write to stdout"), - BLTIN("eval" , builtin_eval , "Construct and run shell command"), - BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"), - BLTIN("exit" , builtin_exit , "Exit"), - BLTIN("export" , builtin_export , "Set environment variable"), + BLTIN("eval" , builtin_eval , "Construct and run shell command"), + BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"), + BLTIN("exit" , builtin_exit , "Exit"), + BLTIN("export" , builtin_export , "Set environment variables"), #if ENABLE_HUSH_JOB - BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"), + BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"), #endif #if ENABLE_HUSH_HELP - BLTIN("help" , builtin_help , "List shell built-in commands"), + BLTIN("help" , builtin_help , NULL), #endif #if ENABLE_HUSH_JOB - BLTIN("jobs" , builtin_jobs , "List active jobs"), + BLTIN("jobs" , builtin_jobs , "List jobs"), #endif #if ENABLE_HUSH_LOCAL - BLTIN("local" , builtin_local , "Set local variable"), + BLTIN("local" , builtin_local , "Set local variables"), #endif #if HUSH_DEBUG - BLTIN("memleak" , builtin_memleak , "Debug tool"), + BLTIN("memleak" , builtin_memleak , NULL), #endif - BLTIN("pwd" , builtin_pwd , "Print current directory"), - BLTIN("read" , builtin_read , "Input environment variable"), + BLTIN("read" , builtin_read , "Input into variable"), #if ENABLE_HUSH_FUNCTIONS - BLTIN("return" , builtin_return , "Return from a function"), -#endif - BLTIN("set" , builtin_set , "Set/unset shell local variables"), - BLTIN("shift" , builtin_shift , "Shift positional parameters"), - BLTIN("test" , builtin_test , "Test condition"), - BLTIN("trap" , builtin_trap , "Trap signals"), - BLTIN("type" , builtin_type , "Write a description of command type"), -// BLTIN("ulimit" , builtin_ulimit , "Control resource limits"), - BLTIN("umask" , builtin_umask , "Set file creation mask"), - BLTIN("unset" , builtin_unset , "Unset environment variable"), - BLTIN("wait" , builtin_wait , "Wait for process"), + BLTIN("return" , builtin_return , "Return from a function"), +#endif + BLTIN("set" , builtin_set , "Set/unset positional parameters"), + BLTIN("shift" , builtin_shift , "Shift positional parameters"), + BLTIN("trap" , builtin_trap , "Trap signals"), + BLTIN("type" , builtin_type , "Write a description of command type"), +// BLTIN("ulimit" , builtin_ulimit , "Control resource limits"), + BLTIN("umask" , builtin_umask , "Set file creation mask"), + BLTIN("unset" , builtin_unset , "Unset variables"), + BLTIN("wait" , builtin_wait , "Wait for process"), +}; +/* For now, echo and test are unconditionally enabled. + * Maybe make it configurable? */ +static const struct built_in_command bltins2[] = { + BLTIN("[" , builtin_test , NULL), + BLTIN("echo" , builtin_echo , NULL), + BLTIN("pwd" , builtin_pwd , NULL), + BLTIN("test" , builtin_test , NULL), }; @@ -1231,15 +1233,17 @@ static int check_and_run_traps(int sig) } -static const char *set_cwd(void) +static const char *get_cwd(int force) { - /* xrealloc_getcwd_or_warn(arg) calls free(arg), - * we must not try to free(bb_msg_unknown) */ - if (G.cwd == bb_msg_unknown) - G.cwd = NULL; - G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd); - if (!G.cwd) - G.cwd = bb_msg_unknown; + if (force || G.cwd == NULL) { + /* xrealloc_getcwd_or_warn(arg) calls free(arg), + * we must not try to free(bb_msg_unknown) */ + if (G.cwd == bb_msg_unknown) + G.cwd = NULL; + G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd); + if (!G.cwd) + G.cwd = bb_msg_unknown; + } return G.cwd; } @@ -1579,7 +1583,7 @@ static const char* setup_prompt_string(int promptmode) /* Set up the prompt */ if (promptmode == 0) { /* PS1 */ free((char*)G.PS1); - G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#'); + G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#'); prompt_str = G.PS1; } else prompt_str = G.PS2; @@ -2511,7 +2515,9 @@ static char **expand_assignments(char **argv, int count) #if BB_MMU /* never called */ -void re_execute_shell(char ***to_free, const char *s, char *argv0, char **argv); +void re_execute_shell(char ***to_free, const char *s, + char *g_argv0, char **g_argv, + char **builtin_argv) NORETURN; static void reset_traps_to_defaults(void) { @@ -2563,10 +2569,14 @@ static void reset_traps_to_defaults(void) #else /* !BB_MMU */ -static void re_execute_shell(char ***to_free, const char *s, char *g_argv0, char **g_argv) NORETURN; -static void re_execute_shell(char ***to_free, const char *s, char *g_argv0, char **g_argv) +static void re_execute_shell(char ***to_free, const char *s, + char *g_argv0, char **g_argv, + char **builtin_argv) NORETURN; +static void re_execute_shell(char ***to_free, const char *s, + char *g_argv0, char **g_argv, + char **builtin_argv) { - char param_buf[sizeof("-$%x:%x:%x:%x") + sizeof(unsigned) * 4]; + char param_buf[sizeof("-$%x:%x:%x:%x:%x") + sizeof(unsigned) * 2]; char *heredoc_argv[4]; struct variable *cur; #if ENABLE_HUSH_FUNCTIONS @@ -2585,16 +2595,22 @@ static void re_execute_shell(char ***to_free, const char *s, char *g_argv0, char goto do_exec; } - sprintf(param_buf, "-$%x:%x:%x" IF_HUSH_LOOPS(":%x") + cnt = 0; + pp = builtin_argv; + if (pp) while (*pp++) + cnt++; + + sprintf(param_buf, "-$%x:%x:%x:%x" IF_HUSH_LOOPS(":%x") , (unsigned) G.root_pid , (unsigned) G.last_bg_pid , (unsigned) G.last_exitcode + , cnt IF_HUSH_LOOPS(, G.depth_of_loop) ); /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<depth> <vars...> <funcs...> * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL */ - cnt = 6; + cnt += 6; for (cur = G.top_var; cur; cur = cur->next) { if (!cur->flg_export || cur->flg_read_only) cnt += 2; @@ -2648,6 +2664,11 @@ static void re_execute_shell(char ***to_free, const char *s, char *g_argv0, char */ *pp++ = (char *) "-c"; *pp++ = (char *) s; + if (builtin_argv) { + while (*++builtin_argv) + *pp++ = *builtin_argv; + *pp++ = (char *) ""; + } *pp++ = g_argv0; while (*g_argv) *pp++ = *g_argv++; @@ -2735,7 +2756,7 @@ static void setup_heredoc(struct redir_struct *redir) #else /* Delegate blocking writes to another process */ xmove_fd(pair.wr, STDOUT_FILENO); - re_execute_shell(&to_free, heredoc, NULL, NULL); + re_execute_shell(&to_free, heredoc, NULL, NULL, NULL); #endif } /* parent */ @@ -2958,17 +2979,31 @@ static char *find_in_path(const char *arg) return ret; } -static const struct built_in_command* find_builtin(const char *name) +static const struct built_in_command* find_builtin_helper(const char *name, + const struct built_in_command *x, + const struct built_in_command *end) { - const struct built_in_command *x; - for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) { - if (strcmp(name, x->cmd) != 0) + while (x != end) { + if (strcmp(name, x->cmd) != 0) { + x++; continue; + } debug_printf_exec("found builtin '%s'\n", name); return x; } return NULL; } +static const struct built_in_command* find_builtin1(const char *name) +{ + return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]); +} +static const struct built_in_command* find_builtin(const char *name) +{ + const struct built_in_command *x = find_builtin1(name); + if (x) + return x; + return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]); +} #if ENABLE_HUSH_FUNCTIONS static const struct function *find_function(const char *name) @@ -3084,7 +3119,8 @@ static void exec_function(nommu_save_t *nommu_save, re_execute_shell(&nommu_save->argv_from_re_execing, funcp->body_as_string, G.global_argv[0], - argv + 1); + argv + 1, + NULL); # endif } @@ -3148,6 +3184,37 @@ static int run_function(const struct function *funcp, char **argv) #endif /* ENABLE_HUSH_FUNCTIONS */ +# if BB_MMU +#define exec_builtin(nommu_save, x, argv) \ + exec_builtin(x, argv) +# else +#define exec_builtin(nommu_save, x, argv) \ + exec_builtin(nommu_save, argv) +# endif +static void exec_builtin(nommu_save_t *nommu_save, + const struct built_in_command *x, + char **argv) NORETURN; +static void exec_builtin(nommu_save_t *nommu_save, + const struct built_in_command *x, + char **argv) +{ +# if BB_MMU + int rcode = x->function(argv); + fflush(NULL); + _exit(rcode); +# else + /* On NOMMU, we must never block! + * Example: { sleep 99 | read line; } & echo Ok + */ + re_execute_shell(&nommu_save->argv_from_re_execing, + argv[0], + G.global_argv[0], + G.global_argv + 1, + argv); +# endif +} + + #if BB_MMU #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \ pseudo_exec_argv(argv, assignment_cnt, argv_expanded) @@ -3197,27 +3264,22 @@ static void pseudo_exec_argv(nommu_save_t *nommu_save, goto skip; #endif - /* On NOMMU, we must never block! - * Example: { sleep 99999 | read line } & echo Ok - * read builtin will block on read syscall, leaving parent blocked - * in vfork. Therefore we can't do this: - */ -#if BB_MMU /* Check if the command matches any of the builtins. * Depending on context, this might be redundant. But it's * easier to waste a few CPU cycles than it is to figure out * if this is one of those cases. */ { - int rcode; - const struct built_in_command *x = find_builtin(argv[0]); + /* On NOMMU, it is more expensive to re-execute shell + * just in order to run echo or test builtin. + * It's better to skip it here and run corresponding + * non-builtin later. */ + const struct built_in_command *x; + x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]); if (x) { - rcode = x->function(argv); - fflush(NULL); - _exit(rcode); + exec_builtin(nommu_save, x, argv); } } -#endif #if ENABLE_HUSH_FUNCTIONS /* Check if the command matches any functions */ { @@ -3292,7 +3354,8 @@ static void pseudo_exec(nommu_save_t *nommu_save, re_execute_shell(&nommu_save->argv_from_re_execing, command->group_as_string, G.global_argv[0], - G.global_argv + 1); + G.global_argv + 1, + NULL); #endif } @@ -5030,7 +5093,8 @@ static FILE *generate_stream_from_string(const char *s) re_execute_shell(&to_free, s, G.global_argv[0], - G.global_argv + 1); + G.global_argv + 1, + NULL); #endif } @@ -6240,6 +6304,7 @@ int hush_main(int argc, char **argv) }; int signal_mask_is_inited = 0; int opt; + unsigned builtin_argc; char **e; struct variable *cur_var; @@ -6277,7 +6342,6 @@ int hush_main(int argc, char **argv) G.global_argc = argc; G.global_argv = argv; /* Initialize some more globals to non-zero values */ - set_cwd(); cmdedit_update_prompt(); if (setjmp(die_jmp)) { @@ -6297,6 +6361,7 @@ int hush_main(int argc, char **argv) /* Parse options */ /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */ + builtin_argc = 0; while (1) { opt = getopt(argc, argv, "c:xins" #if !BB_MMU @@ -6310,15 +6375,40 @@ int hush_main(int argc, char **argv) break; switch (opt) { case 'c': + /* Possibilities: + * sh ... -c 'script' + * sh ... -c 'script' ARG0 [ARG1...] + * On NOMMU, if builtin_argc != 0, + * sh ... -c 'builtin' [BARGV...] "" ARG0 [ARG1...] + * "" needs to be replaced with NULL + * and BARGV vector fed to builtin function. + * Note: this form never happens: + * sh ... -c 'builtin' [BARGV...] "" + */ if (!G.root_pid) G.root_pid = getpid(); G.global_argv = argv + optind; - if (!argv[optind]) { - /* -c 'script' (no params): prevent empty $0 */ - *--G.global_argv = argv[0]; - optind--; - } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */ G.global_argc = argc - optind; + if (builtin_argc) { + /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */ + const struct built_in_command *x; + + block_signals(0); /* 0: called 1st time */ + x = find_builtin(optarg); + if (x) { /* paranoia */ + G.global_argc -= builtin_argc; /* skip [BARGV...] "" */ + G.global_argv += builtin_argc; + G.global_argv[-1] = NULL; /* replace "" */ + G.last_exitcode = x->function(argv + optind - 1); + } + goto final_return; + } + if (!G.global_argv[0]) { + /* -c 'script' (no params): prevent empty $0 */ + G.global_argv--; /* points to argv[i] of 'script' */ + G.global_argv[0] = argv[0]; + G.global_argc--; + } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */ block_signals(0); /* 0: called 1st time */ parse_and_run_string(optarg); goto final_return; @@ -6341,6 +6431,8 @@ int hush_main(int argc, char **argv) G.last_bg_pid = bb_strtou(optarg, &optarg, 16); optarg++; G.last_exitcode = bb_strtou(optarg, &optarg, 16); + optarg++; + builtin_argc = bb_strtou(optarg, &optarg, 16); # if ENABLE_HUSH_LOOPS optarg++; G.depth_of_loop = bb_strtou(optarg, &optarg, 16); @@ -6617,7 +6709,7 @@ static int FAST_FUNC builtin_cd(char **argv) bb_perror_msg("cd: %s", newdir); return EXIT_FAILURE; } - set_cwd(); + get_cwd(1); return EXIT_SUCCESS; } @@ -6663,17 +6755,16 @@ static int FAST_FUNC builtin_exit(char **argv) static void print_escaped(const char *s) { + if (*s == '\'') + goto squote; do { - if (*s != '\'') { - const char *p; - - p = strchrnul(s, '\''); - /* print 'xxxx', possibly just '' */ - printf("'%.*s'", (int)(p - s), s); - if (*p == '\0') - break; - s = p; - } + const char *p = strchrnul(s, '\''); + /* print 'xxxx', possibly just '' */ + printf("'%.*s'", (int)(p - s), s); + if (*p == '\0') + break; + s = p; + squote: /* s points to '; print "'''...'''" */ putchar('"'); do putchar('\''); while (*++s == '\''); @@ -6980,13 +7071,14 @@ static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM) { const struct built_in_command *x; - printf("\n" + printf( "Built-in commands:\n" "------------------\n"); - for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) { - printf("%s\t%s\n", x->cmd, x->descr); + for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) { + if (x->descr) + printf("%s\t%s\n", x->cmd, x->descr); } - printf("\n\n"); + bb_putchar('\n'); return EXIT_SUCCESS; } #endif @@ -7041,7 +7133,7 @@ static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM) static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM) { - puts(set_cwd()); + puts(get_cwd(0)); return EXIT_SUCCESS; } |