diff options
| -rw-r--r-- | shell/hush.c | 487 |
1 files changed, 297 insertions, 190 deletions
diff --git a/shell/hush.c b/shell/hush.c index d7b9c39..58100d4 100644 --- a/shell/hush.c +++ b/shell/hush.c @@ -341,8 +341,9 @@ typedef struct { int maxlen; smallint o_quote; smallint nonnull; + smallint has_empty_slot; } o_string; -#define NULL_O_STRING {NULL,0,0,0,0} +#define NULL_O_STRING { NULL } /* used for initialization: o_string foo = NULL_O_STRING; */ /* I can almost use ordinary FILE *. Is open_memstream() universally @@ -464,8 +465,6 @@ enum { run_list_level = 0 }; } while (0) -#define B_CHUNK 100 -#define B_NOSPAC 1 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n" #if 1 @@ -494,11 +493,6 @@ static void syntax_lineno(int line) #endif /* Index of subroutines: */ -/* o_string manipulation: */ -static int b_check_space(o_string *o, int len); -static int b_addchr(o_string *o, int ch); -static void b_reset(o_string *o); -static int b_addqchr(o_string *o, int ch, int quote); /* in_str manipulations: */ static int static_get(struct in_str *i); static int static_peek(struct in_str *i); @@ -1176,57 +1170,143 @@ static int builtin_unset(char **argv) // return EXIT_FAILURE; //} -static int b_check_space(o_string *o, int len) +/* + * o_string support + */ +#define B_CHUNK (32 * sizeof(char*)) + +static void b_reset(o_string *o) +{ + o->length = 0; + o->nonnull = 0; + if (o->data) + o->data[0] = '\0'; +} + +static void b_free(o_string *o) +{ + free(o->data); + memset(o, 0, sizeof(*o)); +} + +static void b_grow_by(o_string *o, int len) { - /* It would be easy to drop a more restrictive policy - * in here, such as setting a maximum string length */ if (o->length + len > o->maxlen) { - /* assert(data == NULL || o->maxlen != 0); */ o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK); o->data = xrealloc(o->data, 1 + o->maxlen); } - return o->data == NULL; } -static int b_addchr(o_string *o, int ch) +static void b_addchr(o_string *o, int ch) { debug_printf("b_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o); - if (b_check_space(o, 1)) - return B_NOSPAC; + b_grow_by(o, 1); o->data[o->length] = ch; o->length++; o->data[o->length] = '\0'; - return 0; -} - -static void b_reset(o_string *o) -{ - o->length = 0; - o->nonnull = 0; - if (o->data) - o->data[0] = '\0'; } -static void b_free(o_string *o) +static void b_addstr(o_string *o, const char *str, int len) { - free(o->data); - memset(o, 0, sizeof(*o)); + b_grow_by(o, len); + memcpy(&o->data[o->length], str, len); + o->length += len; + o->data[o->length] = '\0'; } /* My analysis of quoting semantics tells me that state information * is associated with a destination, not a source. */ -static int b_addqchr(o_string *o, int ch, int quote) +static void b_addqchr(o_string *o, int ch, int quote) { if (quote && strchr("*?[\\", ch)) { - int rc; - rc = b_addchr(o, '\\'); - if (rc) - return rc; + b_addchr(o, '\\'); + } + b_addchr(o, ch); +} + +/* A special kind of o_string for $VAR and `cmd` expansion. + * It contains char* list[] at the beginning, which is grown in 16 element + * increments. Actual string data starts at the next multiple of 16. + * list[i] contains an INDEX (int!) into this string data. + * It means that if list[] needs to grow, data needs to be moved higher up + * but list[i]'s need not be modified. + * NB: remembering how many list[i]'s you have there is crucial. + * b_finalize_list() operation post-processes this structure - calculates + * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well. + */ +static int b_addptr(o_string *o, int n) +{ + char **list = (char**)o->data; + int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]); + int string_len = o->length - string_start; + + if (!o->has_empty_slot) { + if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */ + /* list[n] points to string_start, make space for 16 more pointers */ + o->maxlen += 0x10 * sizeof(list[0]); + o->data = xrealloc(o->data, o->maxlen + 1); + list = (char**)o->data; + memmove(list + n + 0x10, list + n, string_len); + o->length += 0x10 * sizeof(list[0]); + } + } else { + /* We have empty slot at list[n], reuse without growth */ + o->has_empty_slot = 0; + } + list[n] = (char*)string_len; + return n + 1; +} + +static int b_get_last_ptr(o_string *o, int n) +{ + char **list = (char**)o->data; + int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]); + + return ((int)list[n-1]) + string_start; +} + +static char **b_finalize_list(o_string *o, int n) +{ + char **list = (char**)o->data; + int string_start; + + b_addptr(o, n); /* force growth for list[n] if necessary */ + string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); + list[n] = NULL; + while (n) { + n--; + list[n] = o->data + (int)list[n] + string_start; + } + return list; +} + +#ifdef DEBUG_EXPAND +static void b_debug_list(const char *prefix, o_string *o, int n) +{ + char **list = (char**)o->data; + int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]); + int i = 0; + fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n", + prefix, list, n, string_start, o->length, o->maxlen); + while (i < n) { + fprintf(stderr, " list[%d]=%d '%s'\n", i, (int)list[i], + o->data + (int)list[i] + string_start); + i++; + } + if (n) { + const char *p = o->data + (int)list[n] + string_start; + fprintf(stderr, " total_sz:%d\n", (p + strlen(p) + 1) - o->data); } - return b_addchr(o, ch); } +#else +#define b_debug_list(prefix, o, n) ((void)0) +#endif + +/* + * in_str support + */ static int static_get(struct in_str *i) { int ch = *i->p++; @@ -2461,106 +2541,25 @@ static int xglob(o_string *dest, char ***pglob) * followed by strings themself. * Caller can deallocate entire list by single free(list). */ -/* Helpers first: - * count_XXX estimates size of the block we need. It's okay - * to over-estimate sizes a bit, if it makes code simpler */ -static int count_ifs(const char *str) -{ - int cnt = 0; - debug_printf_expand("count_ifs('%s') ifs='%s'", str, ifs); - while (1) { - str += strcspn(str, ifs); - if (!*str) break; - str++; /* str += strspn(str, ifs); */ - cnt++; /* cnt += strspn(str, ifs); - but this code is larger */ - } - debug_printf_expand(" return %d\n", cnt); - return cnt; -} - -static void count_var_expansion_space(int *countp, int *lenp, char *arg) -{ - char first_ch; - int i; - int len = *lenp; - int count = *countp; - const char *val; - char *p; - - while ((p = strchr(arg, SPECIAL_VAR_SYMBOL))) { - len += p - arg; - arg = ++p; - p = strchr(p, SPECIAL_VAR_SYMBOL); - first_ch = arg[0]; - - switch (first_ch & 0x7f) { - /* high bit in 1st_ch indicates that var is double-quoted */ - case '$': /* pid */ - case '!': /* bg pid */ - case '?': /* exitcode */ - case '#': /* argc */ - len += sizeof(int)*3 + 1; /* enough for int */ - break; - case '*': - case '@': - for (i = 1; global_argv[i]; i++) { - len += strlen(global_argv[i]) + 1; - count++; - if (!(first_ch & 0x80)) - count += count_ifs(global_argv[i]); - } - break; - default: - *p = '\0'; - arg[0] = first_ch & 0x7f; - if (isdigit(arg[0])) { - i = xatoi_u(arg); - val = NULL; - if (i < global_argc) - val = global_argv[i]; - } else - val = lookup_param(arg); - arg[0] = first_ch; - *p = SPECIAL_VAR_SYMBOL; - - if (val) { - len += strlen(val) + 1; - if (!(first_ch & 0x80)) - count += count_ifs(val); - } - } - arg = ++p; - } - - len += strlen(arg) + 1; - count++; - *lenp = len; - *countp = count; -} - /* Store given string, finalizing the word and starting new one whenever * we encounter ifs char(s). This is used for expanding variable values. * End-of-string does NOT finalize word: think about 'echo -$VAR-' */ -static int expand_on_ifs(char **list, int n, char **posp, const char *str) +static int expand_on_ifs(o_string *output, int n, const char *str) { - char *pos = *posp; while (1) { int word_len = strcspn(str, ifs); if (word_len) { - memcpy(pos, str, word_len); /* store non-ifs chars */ - pos += word_len; + b_addstr(output, str, word_len); /* store non-ifs chars */ str += word_len; } if (!*str) /* EOL - do not finalize word */ break; - *pos++ = '\0'; - if (n) debug_printf_expand("expand_on_ifs finalized list[%d]=%p '%s' " - "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1], - strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos); - list[n++] = pos; + b_addchr(output, '\0'); + b_debug_list("expand_on_ifs", output, n); + n = b_addptr(output, n); str += strspn(str, ifs); /* skip ifs chars */ } - *posp = pos; + b_debug_list("expand_on_ifs[1]", output, n); return n; } @@ -2571,7 +2570,7 @@ static int expand_on_ifs(char **list, int n, char **posp, const char *str) * 'echo -$*-'. If you play here, you must run testsuite afterwards! */ /* NB: another bug is that we cannot detect empty strings yet: * "" or $empty"" expands to zero words, has to expand to empty word */ -static int expand_vars_to_list(char **list, int n, char **posp, char *arg, char or_mask) +static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask) { /* or_mask is either 0 (normal case) or 0x80 * (expansion of right-hand side of assignment == 1-element expand) */ @@ -2580,18 +2579,19 @@ static int expand_vars_to_list(char **list, int n, char **posp, char *arg, char int i; const char *val; char *p; - char *pos = *posp; ored_ch = 0; - if (n) debug_printf_expand("expand_vars_to_list finalized list[%d]=%p '%s' " - "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1], - strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos); - list[n++] = pos; + debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg); + b_debug_list("expand_vars_to_list", output, n); + n = b_addptr(output, n); + b_debug_list("expand_vars_to_list[0]", output, n); + + while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) { + o_string subst_result = NULL_O_STRING; - while ((p = strchr(arg, SPECIAL_VAR_SYMBOL))) { - memcpy(pos, arg, p - arg); - pos += (p - arg); + b_addstr(output, arg, p - arg); + b_debug_list("expand_vars_to_list[1]", output, n); arg = ++p; p = strchr(p, SPECIAL_VAR_SYMBOL); @@ -2620,16 +2620,15 @@ static int expand_vars_to_list(char **list, int n, char **posp, char *arg, char break; if (!(first_ch & 0x80)) { /* unquoted $* or $@ */ while (global_argv[i]) { - n = expand_on_ifs(list, n, &pos, global_argv[i]); + n = expand_on_ifs(output, n, global_argv[i]); debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, global_argc-1); if (global_argv[i++][0] && global_argv[i]) { /* this argv[] is not empty and not last: * put terminating NUL, start new word */ - *pos++ = '\0'; - if (n) debug_printf_expand("expand_vars_to_list 2 finalized list[%d]=%p '%s' " - "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1], - strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos); - list[n++] = pos; + b_addchr(output, '\0'); + b_debug_list("expand_vars_to_list[2]", output, n); + n = b_addptr(output, n); + b_debug_list("expand_vars_to_list[3]", output, n); } } } else @@ -2637,27 +2636,34 @@ static int expand_vars_to_list(char **list, int n, char **posp, char *arg, char * and in this case should treat it like '$*' - see 'else...' below */ if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */ while (1) { - strcpy(pos, global_argv[i]); - pos += strlen(global_argv[i]); + b_addstr(output, global_argv[i], strlen(global_argv[i])); if (++i >= global_argc) break; - *pos++ = '\0'; - if (n) debug_printf_expand("expand_vars_to_list 3 finalized list[%d]=%p '%s' " - "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1], - strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos); - list[n++] = pos; + b_addchr(output, '\0'); + b_debug_list("expand_vars_to_list[4]", output, n); + n = b_addptr(output, n); } } else { /* quoted $*: add as one word */ while (1) { - strcpy(pos, global_argv[i]); - pos += strlen(global_argv[i]); + b_addstr(output, global_argv[i], strlen(global_argv[i])); if (!global_argv[++i]) break; if (ifs[0]) - *pos++ = ifs[0]; + b_addchr(output, ifs[0]); } } break; + case '`': { + struct in_str input; + *p = '\0'; + arg++; + //bb_error_msg("SUBST '%s' first_ch %x", arg, first_ch); + setup_string_in_str(&input, arg); + process_command_subs(&subst_result, &input, NULL); + //bb_error_msg("RES '%s'", subst_result.data); + val = subst_result.data; + goto store_val; + } default: *p = '\0'; arg[0] = first_ch & 0x7f; @@ -2669,66 +2675,52 @@ static int expand_vars_to_list(char **list, int n, char **posp, char *arg, char } else val = lookup_param(arg); arg[0] = first_ch; + store_val: *p = SPECIAL_VAR_SYMBOL; if (!(first_ch & 0x80)) { /* unquoted $VAR */ if (val) { - n = expand_on_ifs(list, n, &pos, val); + n = expand_on_ifs(output, n, val); val = NULL; } - } /* else: quoted $VAR, val will be appended at pos */ - } - if (val) { - strcpy(pos, val); - pos += strlen(val); + } /* else: quoted $VAR, val will be appended below */ } + if (val) + b_addstr(output, val, strlen(val)); + + b_free(&subst_result); arg = ++p; - } - debug_printf_expand("expand_vars_to_list adding tail '%s' at %p\n", arg, pos); - strcpy(pos, arg); - pos += strlen(arg) + 1; - if (pos == list[n-1] + 1) { /* expansion is empty */ + } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */ + + b_debug_list("expand_vars_to_list[a]", output, n); + b_addstr(output, arg, strlen(arg) + 1); + b_debug_list("expand_vars_to_list[b]", output, n); +//TESTME + if (output->length - 1 == b_get_last_ptr(output, n)) { /* expansion is empty */ if (!(ored_ch & 0x80)) { /* all vars were not quoted... */ - debug_printf_expand("expand_vars_to_list list[%d] empty, going back\n", n); - pos--; n--; + /* allow to reuse list[n] later without re-growth */ + output->has_empty_slot = 1; } } - *posp = pos; return n; } static char **expand_variables(char **argv, char or_mask) { int n; - int count = 1; - int len = 0; - char *pos, **v, **list; + char **list; + char **v; + o_string output = NULL_O_STRING; - v = argv; - if (!*v) debug_printf_expand("count_var_expansion_space: " - "argv[0]=NULL count=%d len=%d alloc_space=%d\n", - count, len, sizeof(char*) * count + len); - while (*v) { - count_var_expansion_space(&count, &len, *v); - debug_printf_expand("count_var_expansion_space: " - "'%s' count=%d len=%d alloc_space=%d\n", - *v, count, len, sizeof(char*) * count + len); - v++; - } - len += sizeof(char*) * count; /* total to alloc */ - list = xmalloc(len); - pos = (char*)(list + count); - debug_printf_expand("list=%p, list[0] should be %p\n", list, pos); n = 0; v = argv; while (*v) - n = expand_vars_to_list(list, n, &pos, *v++, or_mask); + n = expand_vars_to_list(&output, n, *v++, or_mask); + b_debug_list("expand_variables", &output, n); - if (n) debug_printf_expand("finalized list[%d]=%p '%s' " - "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1], - strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos); - list[n] = NULL; + /* output.data (malloced) gets returned in "list" */ + list = b_finalize_list(&output, n); #ifdef DEBUG_EXPAND { @@ -2737,12 +2729,8 @@ static char **expand_variables(char **argv, char or_mask) debug_printf_expand("list[%d]=%p '%s'\n", m, list[m], list[m]); m++; } - debug_printf_expand("used_space=%d\n", pos - (char*)list); } #endif - if (ENABLE_HUSH_DEBUG) - if (pos - (char*)list > len) - bb_error_msg_and_die("BUG in varexp"); return list; } @@ -3391,6 +3379,116 @@ static const char *lookup_param(const char *src) return NULL; } +#if ENABLE_HUSH_TICK +/* Subroutines for copying $(...) and `...` things */ +static void add_till_backquote(o_string *dest, struct in_str *input); +/* '...' */ +static void add_till_single_quote(o_string *dest, struct in_str *input) +{ + while (1) { + int ch = b_getch(input); + if (ch == EOF) + break; + if (ch == '\'') + break; + b_addchr(dest, ch); + } +} +/* "...\"...`..`...." - do we need to handle "...$(..)..." too? */ +static void add_till_double_quote(o_string *dest, struct in_str *input) +{ + while (1) { + int ch = b_getch(input); + if (ch == '"') + break; + if (ch == '\\') { /* \x. Copy both chars. */ + b_addchr(dest, ch); + ch = b_getch(input); + } + if (ch == EOF) + break; + b_addchr(dest, ch); + if (ch == '`') { + add_till_backquote(dest, input); + b_addchr(dest, ch); + continue; + } +// if (ch == '$') ... + } +} +/* Process `cmd` - copy contents until "`" is seen. Complicated by + * \` quoting. + * "Within the backquoted style of command substitution, backslash + * shall retain its literal meaning, except when followed by: '$', '`', or '\'. + * The search for the matching backquote shall be satisfied by the first + * backquote found without a preceding backslash; during this search, + * if a non-escaped backquote is encountered within a shell comment, + * a here-document, an embedded command substitution of the $(command) + * form, or a quoted string, undefined results occur. A single-quoted + * or double-quoted string that begins, but does not end, within the + * "`...`" sequence produces undefined results." + * Example Output + * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST + */ +static void add_till_backquote(o_string *dest, struct in_str *input) +{ + while (1) { + int ch = b_getch(input); +//bb_error_msg("ADD '%c'", ch); + if (ch == '`') + break; + if (ch == '\\') { /* \x. Copy both chars unless it is \` */ + int ch2 = b_getch(input); + if (ch2 != '`' && ch2 != '$' && ch2 != '\\') + b_addchr(dest, ch); + ch = ch2; + } + if (ch == EOF) + break; + b_addchr(dest, ch); + } +} +/* Process $(cmd) - copy contents until ")" is seen. Complicated by + * quoting and nested ()s. + * "With the $(command) style of command substitution, all characters + * following the open parenthesis to the matching closing parenthesis + * constitute the command. Any valid shell script can be used for command, + * except a script consisting solely of redirections which produces + * unspecified results." + * Example Output + * echo $(echo '(TEST)' BEST) (TEST) BEST + * echo $(echo 'TEST)' BEST) TEST) BEST + * echo $(echo \(\(TEST\) BEST) ((TEST) BEST + */ +static void add_till_closing_curly_brace(o_string *dest, struct in_str *input) +{ + int count = 0; + while (1) { + int ch = b_getch(input); + if (ch == EOF) + break; + if (ch == '(') + count++; + if (ch == ')') + if (--count < 0) + break; + b_addchr(dest, ch); + if (ch == '\'') { + add_till_single_quote(dest, input); + b_addchr(dest, ch); + continue; + } + if (ch == '"') { + add_till_double_quote(dest, input); + b_addchr(dest, ch); + continue; + } + } +} +#endif /* ENABLE_HUSH_TICK */ + +//FIXME: remove ctx and sp + /* return code: 0 for OK, 1 for syntax error */ static int handle_dollar(o_string *dest, /*struct p_context *ctx,*/ struct in_str *input) { @@ -3450,7 +3548,10 @@ static int handle_dollar(o_string *dest, /*struct p_context *ctx,*/ struct in_st #if ENABLE_HUSH_TICK case '(': b_getch(input); - process_command_subs(dest, /*ctx,*/ input, ")"); + b_addchr(dest, SPECIAL_VAR_SYMBOL); + b_addchr(dest, quote_mask | '`'); + add_till_closing_curly_brace(dest, input); + b_addchr(dest, SPECIAL_VAR_SYMBOL); break; #endif case '-': @@ -3572,9 +3673,15 @@ static int parse_stream(o_string *dest, struct p_context *ctx, dest->o_quote ^= 1; /* invert */ break; #if ENABLE_HUSH_TICK - case '`': - process_command_subs(dest, /*ctx,*/ input, "`"); + case '`': { + //int pos = dest->length; + b_addchr(dest, SPECIAL_VAR_SYMBOL); + b_addchr(dest, dest->o_quote ? 0x80 | '`' : '`'); + add_till_backquote(dest, input); + b_addchr(dest, SPECIAL_VAR_SYMBOL); + //bb_error_msg("RES '%s'", dest->data + pos); break; + } #endif case '>': redir_fd = redirect_opt_num(dest); |