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-rw-r--r--shell/hush.c487
1 files changed, 297 insertions, 190 deletions
diff --git a/shell/hush.c b/shell/hush.c
index d7b9c39ec..58100d4d1 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);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-15 00:58:03 +0000