diff options
| -rw-r--r-- | shell/hush.c | 166 |
1 files changed, 115 insertions, 51 deletions
diff --git a/shell/hush.c b/shell/hush.c index f81203e..b832658 100644 --- a/shell/hush.c +++ b/shell/hush.c @@ -227,8 +227,8 @@ typedef enum { REDIRECT_IO = 5 } redir_type; -/* The descrip member of this structure is only used to make debugging - * output pretty */ +/* The descrip member of this structure is only used to make + * debugging output pretty */ static const struct { int mode; signed char default_fd; @@ -283,8 +283,8 @@ struct p_context { }; struct redir_struct { - struct redir_struct *next; /* pointer to the next redirect in the list */ - redir_type type; /* type of redirection */ + struct redir_struct *next; + smallint /*redir_type*/ rd_type; int fd; /* file descriptor being redirected */ int dup; /* -1, or file descriptor being duplicated */ char *rd_filename; /* filename */ @@ -292,10 +292,10 @@ struct redir_struct { struct child_prog { pid_t pid; /* 0 if exited */ + smallint is_stopped; /* is the program currently running? */ + smallint subshell; /* flag, non-zero if group must be forked */ char **argv; /* program name and arguments */ struct pipe *group; /* if non-NULL, first in group or subshell */ - smallint subshell; /* flag, non-zero if group must be forked */ - smallint is_stopped; /* is the program currently running? */ struct redir_struct *redirects; /* I/O redirections */ struct pipe *family; /* pointer back to the child's parent pipe */ }; @@ -346,7 +346,13 @@ typedef struct { smallint o_glob; smallint nonnull; smallint has_empty_slot; + smallint o_assignment; /* 0:maybe, 1:yes, 2:no */ } o_string; +enum { + MAYBE_ASSIGNMENT = 0, + DEFINITELY_ASSIGNMENT = 1, + NOT_ASSIGNMENT = 2, +}; /* Used for initialization: o_string foo = NULL_O_STRING; */ #define NULL_O_STRING { NULL } @@ -588,6 +594,19 @@ static int is_assignment(const char *s) return *s == '='; } +/* Replace each \x with x in place, return ptr past NUL. */ +static char *unbackslash(char *src) +{ + char *dst = src; + while (1) { + if (*src == '\\') + src++; + if ((*dst++ = *src++) == '\0') + break; + } + return dst; +} + static char **add_malloced_strings_to_strings(char **strings, char **add) { int i; @@ -906,6 +925,19 @@ static void o_addstr(o_string *o, const char *str, int len) o->data[o->length] = '\0'; } +static void o_addstr_duplicate_backslash(o_string *o, const char *str, int len) +{ + while (len) { + o_addchr(o, *str); + if (*str++ == '\\' + && (*str != '*' && *str != '?' && *str != '[') + ) { + o_addchr(o, '\\'); + } + len--; + } +} + /* My analysis of quoting semantics tells me that state information * is associated with a destination, not a source. */ @@ -1045,18 +1077,7 @@ static int o_get_last_ptr(o_string *o, int n) } /* o_glob performs globbing on last list[], saving each result - * as a new list[]. unbackslash() is just a helper */ -static char *unbackslash(char *src) -{ - char *dst = src; - while (1) { - if (*src == '\\') - src++; - if ((*dst++ = *src++) == '\0') - break; - } - return dst; -} + * as a new list[]. */ static int o_glob(o_string *o, int n) { glob_t globdata; @@ -1310,7 +1331,8 @@ static int setup_redirects(struct child_prog *prog, int squirrel[]) } if (redir->dup == -1) { char *p; - mode = redir_table[redir->type].mode; + mode = redir_table[redir->rd_type].mode; +//TODO: check redir to names like '\\' p = expand_string_to_string(redir->rd_filename); openfd = open_or_warn(p, mode); free(p); @@ -1765,6 +1787,7 @@ static int run_pipe(struct pipe *pi) for (i = 0; is_assignment(argv[i]); i++) { p = expand_string_to_string(argv[i]); putenv(p); +//FIXME: do we leak p?! } for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) { if (strcmp(argv[i], x->cmd) == 0) { @@ -2300,7 +2323,10 @@ static int expand_on_ifs(o_string *output, int n, const char *str) while (1) { int word_len = strcspn(str, ifs); if (word_len) { - o_addstr(output, str, word_len); + if (output->o_quote || !output->o_glob) + o_addQstr(output, str, word_len); + else /* protect backslashes against globbing up :) */ + o_addstr_duplicate_backslash(output, str, word_len); str += word_len; } if (!*str) /* EOL - do not finalize word */ @@ -2324,7 +2350,8 @@ static int expand_on_ifs(o_string *output, int n, const char *str) 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) */ + * (expansion of right-hand side of assignment == 1-element expand. + * It will also do no globbing, and thus we must not backslash-quote!) */ char first_ch, ored_ch; int i; @@ -2372,6 +2399,7 @@ static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask) break; if (!(first_ch & 0x80)) { /* unquoted $* or $@ */ while (global_argv[i]) { +//see expand_on_ifs below - same?? 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]) { @@ -2429,9 +2457,9 @@ static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask) 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 remains NULL: $N with too big N */ } else val = lookup_param(arg); arg[0] = first_ch; @@ -2442,11 +2470,16 @@ static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask) if (!(first_ch & 0x80)) { /* unquoted $VAR */ debug_printf_expand("unquoted '%s', output->o_quote:%d\n", val, output->o_quote); if (val) { + /* unquoted var's contents should be globbed, so don't quote */ + smallint sv = output->o_quote; + output->o_quote = 0; n = expand_on_ifs(output, n, val); val = NULL; + output->o_quote = sv; } - } else /* quoted $VAR, val will be appended below */ + } else { /* quoted $VAR, val will be appended below */ debug_printf_expand("quoted '%s', output->o_quote:%d\n", val, output->o_quote); + } } if (val) { o_addQstr(output, val, strlen(val)); ///maybe q? @@ -2485,6 +2518,7 @@ static char **expand_variables(char **argv, int or_mask) if (or_mask & 0x100) { output.o_quote = 1; +/* why? */ output.o_glob = 1; } @@ -2687,7 +2721,7 @@ static int setup_redirect(struct p_context *ctx, int fd, redir_type style, child->redirects = redir; } - redir->type = style; + redir->rd_type = style; redir->fd = (fd == -1) ? redir_table[style].default_fd : fd; debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip); @@ -2858,6 +2892,14 @@ static int done_word(o_string *word, struct p_context *ctx) { struct child_prog *child = ctx->child; + /* If this word wasn't an assignment, next ones definitely + * can't be assignments. Even if they look like ones. */ + if (word->o_assignment != DEFINITELY_ASSIGNMENT) { + word->o_assignment = NOT_ASSIGNMENT; + } else { + word->o_assignment = MAYBE_ASSIGNMENT; + } + debug_printf_parse("done_word entered: '%s' %p\n", word->data, child); if (word->length == 0 && word->nonnull == 0) { debug_printf_parse("done_word return 0: true null, ignored\n"); @@ -2867,6 +2909,7 @@ static int done_word(o_string *word, struct p_context *ctx) /* We do not glob in e.g. >*.tmp case. bash seems to glob here * only if run as "bash", not "sh" */ ctx->pending_redirect->rd_filename = xstrdup(word->data); + word->o_assignment = NOT_ASSIGNMENT; debug_printf("word stored in rd_filename: '%s'\n", word->data); } else { if (child->group) { /* TODO: example how to trigger? */ @@ -2878,15 +2921,18 @@ static int done_word(o_string *word, struct p_context *ctx) debug_printf_parse(": checking '%s' for reserved-ness\n", word->data); if (reserved_word(word, ctx)) { o_reset(word); + word->o_assignment = NOT_ASSIGNMENT; debug_printf_parse("done_word return %d\n", (ctx->res_w == RES_SNTX)); return (ctx->res_w == RES_SNTX); } } - if (word->nonnull - /* && word->data[0] != */ + if (word->nonnull /* we saw "xx" or 'xx' */ + /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */ + && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL) + /* (otherwise it's "abc".... and is already safe) */ ) { - /* Insert "empty variable" reference, this makes e.g. "", '', - * $empty"" etc to not disappear */ + /* Insert "empty variable" reference, this makes + * e.g. "", $empty"" etc to not disappear */ o_addchr(word, SPECIAL_VAR_SYMBOL); o_addchr(word, SPECIAL_VAR_SYMBOL); } @@ -3107,14 +3153,14 @@ static int process_command_subs(o_string *dest, continue; } while (eol_cnt) { - o_addQchr(dest, '\n'); + o_addchr(dest, '\n'); eol_cnt--; } - /* Even unquoted `echo '\'` results in two backslashes - * (which are converted into one by globbing later) */ - if (!dest->o_quote && ch == '\\') { - o_addchr(dest, ch); - } +// /* Even unquoted `echo '\'` results in two backslashes +// * (which are converted into one by globbing later) */ +// if (!dest->o_quote && ch == '\\') { +// o_addchr(dest, ch); +// } o_addQchr(dest, ch); } @@ -3364,13 +3410,19 @@ static int handle_dollar(o_string *dest, struct in_str *input) return 0; } -/* Return code is 0 for normal exit, 1 for syntax error */ +/* Scan input, call done_word() whenever full IFS delemited word was seen. + * call done_pipe if '\n' was seen (and end_trigger != NULL) + * Return if (non-quoted) char in end_trigger was seen; or on parse error. */ +/* Return code is 0 if end_trigger char is met, + * -1 on EOF (but if end_trigger == NULL then return 0) + * 1 for syntax error */ static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input, const char *end_trigger) { int ch, m; int redir_fd; redir_type redir_style; + int shadow_quote = dest->o_quote; int next; /* Only double-quote state is handled in the state variable dest->o_quote. @@ -3385,13 +3437,14 @@ static int parse_stream(o_string *dest, struct p_context *ctx, ch = i_getch(input); if (ch != EOF) { m = charmap[ch]; - if (ch != '\n') + if (ch != '\n') { next = i_peek(input); + } } debug_printf_parse(": ch=%c (%d) m=%d quote=%d\n", ch, ch, m, dest->o_quote); if (m == CHAR_ORDINARY - || (m != CHAR_SPECIAL && dest->o_quote) + || (m != CHAR_SPECIAL && shadow_quote) ) { if (ch == EOF) { syntax("unterminated \""); @@ -3399,6 +3452,12 @@ static int parse_stream(o_string *dest, struct p_context *ctx, return 1; } o_addQchr(dest, ch); + if (dest->o_assignment == MAYBE_ASSIGNMENT + && ch == '=' + && is_assignment(dest->data) + ) { + dest->o_assignment = DEFINITELY_ASSIGNMENT; + } continue; } if (m == CHAR_IFS) { @@ -3416,11 +3475,12 @@ static int parse_stream(o_string *dest, struct p_context *ctx, } } if (end_trigger) { - if (!dest->o_quote && strchr(end_trigger, ch)) { + if (!shadow_quote && strchr(end_trigger, ch)) { /* Special case: (...word) makes last word terminate, * as if ';' is seen */ if (ch == ')') { done_word(dest, ctx); +//err chk? done_pipe(ctx, PIPE_SEQ); } if (ctx->res_w == RES_NONE) { @@ -3431,9 +3491,16 @@ static int parse_stream(o_string *dest, struct p_context *ctx, } if (m == CHAR_IFS) continue; + + if (dest->o_assignment == MAYBE_ASSIGNMENT) { + /* ch is a special char and thus this word + * cannot be an assignment: */ + dest->o_assignment = NOT_ASSIGNMENT; + } + switch (ch) { case '#': - if (dest->length == 0 && !dest->o_quote) { + if (dest->length == 0 && !shadow_quote) { while (1) { ch = i_peek(input); if (ch == EOF || ch == '\n') @@ -3459,7 +3526,7 @@ static int parse_stream(o_string *dest, struct p_context *ctx, * an ! appearing in double quotes is escaped using * a backslash. The backslash preceding the ! is not removed." */ - if (dest->o_quote) { + if (shadow_quote) { //NOT SURE dest->o_quote) { if (strchr("$`\"\\", next) != NULL) { o_addqchr(dest, i_getch(input)); } else { @@ -3487,18 +3554,23 @@ static int parse_stream(o_string *dest, struct p_context *ctx, } if (ch == '\'') break; - o_addqchr(dest, ch); + if (dest->o_assignment == NOT_ASSIGNMENT) + o_addqchr(dest, ch); + else + o_addchr(dest, ch); } break; case '"': dest->nonnull = 1; - dest->o_quote ^= 1; /* invert */ + shadow_quote ^= 1; /* invert */ + if (dest->o_assignment == NOT_ASSIGNMENT) + dest->o_quote ^= 1; break; #if ENABLE_HUSH_TICK case '`': { //int pos = dest->length; o_addchr(dest, SPECIAL_VAR_SYMBOL); - o_addchr(dest, dest->o_quote ? 0x80 | '`' : '`'); + o_addchr(dest, shadow_quote /*or dest->o_quote??*/ ? 0x80 | '`' : '`'); add_till_backquote(dest, input); o_addchr(dest, SPECIAL_VAR_SYMBOL); //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos); @@ -3585,14 +3657,6 @@ static int parse_stream(o_string *dest, struct p_context *ctx, bb_error_msg_and_die("BUG: unexpected %c\n", ch); } } /* while (1) */ - /* Complain if quote? No, maybe we just finished a command substitution - * that was quoted. Example: - * $ echo "`cat foo` plus more" - * and we just got the EOF generated by the subshell that ran "cat foo" - * The only real complaint is if we got an EOF when end_trigger != NULL, - * that is, we were really supposed to get end_trigger, and never got - * one before the EOF. Can't use the standard "syntax error" return code, - * so that parse_stream_outer can distinguish the EOF and exit smoothly. */ debug_printf_parse("parse_stream return %d\n", -(end_trigger != NULL)); if (end_trigger) return -1; |