1 files changed, 478 insertions, 0 deletions

diff --git a/libbb/quote.c b/libbb/quote.c
new file mode 100644
index 000000000..7a49fcf69
--- /dev/null
+++ b/libbb/quote.c
@@ -0,0 +1,478 @@
+#include "cache.h"
+#include "quote.h"
+
+int quote_path_fully = 1;
+
+/* Help to copy the thing properly quoted for the shell safety.
+ * any single quote is replaced with '\'', any exclamation point
+ * is replaced with '\!', and the whole thing is enclosed in a
+ *
+ * E.g.
+ *  original     sq_quote     result
+ *  name     ==> name      ==> 'name'
+ *  a b      ==> a b       ==> 'a b'
+ *  a'b      ==> a'\''b    ==> 'a'\''b'
+ *  a!b      ==> a'\!'b    ==> 'a'\!'b'
+ */
+static inline int need_bs_quote(char c)
+{
+        return (c == '\'' || c == '!');
+}
+
+void sq_quote_buf(struct strbuf *dst, const char *src)
+{
+        char *to_free = NULL;
+
+        if (dst->buf == src)
+                to_free = strbuf_detach(dst, NULL);
+
+        strbuf_addch(dst, '\'');
+        while (*src) {
+                size_t len = strcspn(src, "'!");
+                strbuf_add(dst, src, len);
+                src += len;
+                while (need_bs_quote(*src)) {
+                        strbuf_addstr(dst, "'\\");
+                        strbuf_addch(dst, *src++);
+                        strbuf_addch(dst, '\'');
+                }
+        }
+        strbuf_addch(dst, '\'');
+        free(to_free);
+}
+
+void sq_quote_print(FILE *stream, const char *src)
+{
+        char c;
+
+        fputc('\'', stream);
+        while ((c = *src++)) {
+                if (need_bs_quote(c)) {
+                        fputs("'\\", stream);
+                        fputc(c, stream);
+                        fputc('\'', stream);
+                } else {
+                        fputc(c, stream);
+                }
+        }
+        fputc('\'', stream);
+}
+
+void sq_quote_argv(struct strbuf *dst, const char** argv, size_t maxlen)
+{
+        int i;
+
+        /* Copy into destination buffer. */
+        strbuf_grow(dst, 255);
+        for (i = 0; argv[i]; ++i) {
+                strbuf_addch(dst, ' ');
+                sq_quote_buf(dst, argv[i]);
+                if (maxlen && dst->len > maxlen)
+                        die("Too many or long arguments");
+        }
+}
+
+char *sq_dequote_step(char *arg, char **next)
+{
+        char *dst = arg;
+        char *src = arg;
+        char c;
+
+        if (*src != '\'')
+                return NULL;
+        for (;;) {
+                c = *++src;
+                if (!c)
+                        return NULL;
+                if (c != '\'') {
+                        *dst++ = c;
+                        continue;
+                }
+                /* We stepped out of sq */
+                switch (*++src) {
+                case '\0':
+                        *dst = 0;
+                        if (next)
+                                *next = NULL;
+                        return arg;
+                case '\\':
+                        c = *++src;
+                        if (need_bs_quote(c) && *++src == '\'') {
+                                *dst++ = c;
+                                continue;
+                        }
+                /* Fallthrough */
+                default:
+                        if (!next || !isspace(*src))
+                                return NULL;
+                        do {
+                                c = *++src;
+                        } while (isspace(c));
+                        *dst = 0;
+                        *next = src;
+                        return arg;
+                }
+        }
+}
+
+char *sq_dequote(char *arg)
+{
+        return sq_dequote_step(arg, NULL);
+}
+
+int sq_dequote_to_argv(char *arg, const char ***argv, int *nr, int *alloc)
+{
+        char *next = arg;
+
+        if (!*arg)
+                return 0;
+        do {
+                char *dequoted = sq_dequote_step(next, &next);
+                if (!dequoted)
+                        return -1;
+                ALLOC_GROW(*argv, *nr + 1, *alloc);
+                (*argv)[(*nr)++] = dequoted;
+        } while (next);
+
+        return 0;
+}
+
+/* 1 means: quote as octal
+ * 0 means: quote as octal if (quote_path_fully)
+ * -1 means: never quote
+ * c: quote as "\\c"
+ */
+#define X8(x)   x, x, x, x, x, x, x, x
+#define X16(x)  X8(x), X8(x)
+static signed char const sq_lookup[256] = {
+        /*           0    1    2    3    4    5    6    7 */
+        /* 0x00 */   1,   1,   1,   1,   1,   1,   1, 'a',
+        /* 0x08 */ 'b', 't', 'n', 'v', 'f', 'r',   1,   1,
+        /* 0x10 */ X16(1),
+        /* 0x20 */  -1,  -1, '"',  -1,  -1,  -1,  -1,  -1,
+        /* 0x28 */ X16(-1), X16(-1), X16(-1),
+        /* 0x58 */  -1,  -1,  -1,  -1,'\\',  -1,  -1,  -1,
+        /* 0x60 */ X16(-1), X8(-1),
+        /* 0x78 */  -1,  -1,  -1,  -1,  -1,  -1,  -1,   1,
+        /* 0x80 */ /* set to 0 */
+};
+
+static inline int sq_must_quote(char c)
+{
+        return sq_lookup[(unsigned char)c] + quote_path_fully > 0;
+}
+
+/* returns the longest prefix not needing a quote up to maxlen if positive.
+   This stops at the first \0 because it's marked as a character needing an
+   escape */
+static size_t next_quote_pos(const char *s, ssize_t maxlen)
+{
+        size_t len;
+        if (maxlen < 0) {
+                for (len = 0; !sq_must_quote(s[len]); len++);
+        } else {
+                for (len = 0; len < maxlen && !sq_must_quote(s[len]); len++);
+        }
+        return len;
+}
+
+/*
+ * C-style name quoting.
+ *
+ * (1) if sb and fp are both NULL, inspect the input name and counts the
+ *     number of bytes that are needed to hold c_style quoted version of name,
+ *     counting the double quotes around it but not terminating NUL, and
+ *     returns it.
+ *     However, if name does not need c_style quoting, it returns 0.
+ *
+ * (2) if sb or fp are not NULL, it emits the c_style quoted version
+ *     of name, enclosed with double quotes if asked and needed only.
+ *     Return value is the same as in (1).
+ */
+static size_t quote_c_style_counted(const char *name, ssize_t maxlen,
+                                    struct strbuf *sb, FILE *fp, int no_dq)
+{
+#undef EMIT
+#define EMIT(c)                                 \
+        do {                                        \
+                if (sb) strbuf_addch(sb, (c));          \
+                if (fp) fputc((c), fp);                 \
+                count++;                                \
+        } while (0)
+#define EMITBUF(s, l)                           \
+        do {                                        \
+                if (sb) strbuf_add(sb, (s), (l));       \
+                if (fp) fwrite((s), (l), 1, fp);        \
+                count += (l);                           \
+        } while (0)
+
+        size_t len, count = 0;
+        const char *p = name;
+
+        for (;;) {
+                int ch;
+
+                len = next_quote_pos(p, maxlen);
+                if (len == maxlen || !p[len])
+                        break;
+
+                if (!no_dq && p == name)
+                        EMIT('"');
+
+                EMITBUF(p, len);
+                EMIT('\\');
+                p += len;
+                ch = (unsigned char)*p++;
+                if (sq_lookup[ch] >= ' ') {
+                        EMIT(sq_lookup[ch]);
+                } else {
+                        EMIT(((ch >> 6) & 03) + '0');
+                        EMIT(((ch >> 3) & 07) + '0');
+                        EMIT(((ch >> 0) & 07) + '0');
+                }
+        }
+
+        EMITBUF(p, len);
+        if (p == name)   /* no ending quote needed */
+                return 0;
+
+        if (!no_dq)
+                EMIT('"');
+        return count;
+}
+
+size_t quote_c_style(const char *name, struct strbuf *sb, FILE *fp, int nodq)
+{
+        return quote_c_style_counted(name, -1, sb, fp, nodq);
+}
+
+void quote_two_c_style(struct strbuf *sb, const char *prefix, const char *path, int nodq)
+{
+        if (quote_c_style(prefix, NULL, NULL, 0) ||
+            quote_c_style(path, NULL, NULL, 0)) {
+                if (!nodq)
+                        strbuf_addch(sb, '"');
+                quote_c_style(prefix, sb, NULL, 1);
+                quote_c_style(path, sb, NULL, 1);
+                if (!nodq)
+                        strbuf_addch(sb, '"');
+        } else {
+                strbuf_addstr(sb, prefix);
+                strbuf_addstr(sb, path);
+        }
+}
+
+void write_name_quoted(const char *name, FILE *fp, int terminator)
+{
+        if (terminator) {
+                quote_c_style(name, NULL, fp, 0);
+        } else {
+                fputs(name, fp);
+        }
+        fputc(terminator, fp);
+}
+
+extern void write_name_quotedpfx(const char *pfx, size_t pfxlen,
+                                 const char *name, FILE *fp, int terminator)
+{
+        int needquote = 0;
+
+        if (terminator) {
+                needquote = next_quote_pos(pfx, pfxlen) < pfxlen
+                        || name[next_quote_pos(name, -1)];
+        }
+        if (needquote) {
+                fputc('"', fp);
+                quote_c_style_counted(pfx, pfxlen, NULL, fp, 1);
+                quote_c_style(name, NULL, fp, 1);
+                fputc('"', fp);
+        } else {
+                fwrite(pfx, pfxlen, 1, fp);
+                fputs(name, fp);
+        }
+        fputc(terminator, fp);
+}
+
+/* quote path as relative to the given prefix */
+char *quote_path_relative(const char *in, int len,
+                          struct strbuf *out, const char *prefix)
+{
+        int needquote;
+
+        if (len < 0)
+                len = strlen(in);
+
+        /* "../" prefix itself does not need quoting, but "in" might. */
+        needquote = next_quote_pos(in, len) < len;
+        strbuf_setlen(out, 0);
+        strbuf_grow(out, len);
+
+        if (needquote)
+                strbuf_addch(out, '"');
+        if (prefix) {
+                int off = 0;
+                while (prefix[off] && off < len && prefix[off] == in[off])
+                        if (prefix[off] == '/') {
+                                prefix += off + 1;
+                                in += off + 1;
+                                len -= off + 1;
+                                off = 0;
+                        } else
+                                off++;
+
+                for (; *prefix; prefix++)
+                        if (*prefix == '/')
+                                strbuf_addstr(out, "../");
+        }
+
+        quote_c_style_counted (in, len, out, NULL, 1);
+
+        if (needquote)
+                strbuf_addch(out, '"');
+        if (!out->len)
+                strbuf_addstr(out, "./");
+
+        return out->buf;
+}
+
+/*
+ * C-style name unquoting.
+ *
+ * Quoted should point at the opening double quote.
+ * + Returns 0 if it was able to unquote the string properly, and appends the
+ *   result in the strbuf `sb'.
+ * + Returns -1 in case of error, and doesn't touch the strbuf. Though note
+ *   that this function will allocate memory in the strbuf, so calling
+ *   strbuf_release is mandatory whichever result unquote_c_style returns.
+ *
+ * Updates endp pointer to point at one past the ending double quote if given.
+ */
+int unquote_c_style(struct strbuf *sb, const char *quoted, const char **endp)
+{
+        size_t oldlen = sb->len, len;
+        int ch, ac;
+
+        if (*quoted++ != '"')
+                return -1;
+
+        for (;;) {
+                len = strcspn(quoted, "\"\\");
+                strbuf_add(sb, quoted, len);
+                quoted += len;
+
+                switch (*quoted++) {
+                  case '"':
+                        if (endp)
+                                *endp = quoted;
+                        return 0;
+                  case '\\':
+                        break;
+                  default:
+                        goto error;
+                }
+
+                switch ((ch = *quoted++)) {
+                case 'a': ch = '\a'; break;
+                case 'b': ch = '\b'; break;
+                case 'f': ch = '\f'; break;
+                case 'n': ch = '\n'; break;
+                case 'r': ch = '\r'; break;
+                case 't': ch = '\t'; break;
+                case 'v': ch = '\v'; break;
+
+                case '\\': case '"':
+                        break; /* verbatim */
+
+                /* octal values with first digit over 4 overflow */
+                case '0': case '1': case '2': case '3':
+                                        ac = ((ch - '0') << 6);
+                        if ((ch = *quoted++) < '0' || '7' < ch)
+                                goto error;
+                                        ac |= ((ch - '0') << 3);
+                        if ((ch = *quoted++) < '0' || '7' < ch)
+                                goto error;
+                                        ac |= (ch - '0');
+                                        ch = ac;
+                                        break;
+                                default:
+                        goto error;
+                        }
+                strbuf_addch(sb, ch);
+                }
+
+  error:
+        strbuf_setlen(sb, oldlen);
+        return -1;
+}
+
+/* quoting as a string literal for other languages */
+
+void perl_quote_print(FILE *stream, const char *src)
+{
+        const char sq = '\'';
+        const char bq = '\\';
+        char c;
+
+        fputc(sq, stream);
+        while ((c = *src++)) {
+                if (c == sq || c == bq)
+                        fputc(bq, stream);
+                fputc(c, stream);
+        }
+        fputc(sq, stream);
+}
+
+void python_quote_print(FILE *stream, const char *src)
+{
+        const char sq = '\'';
+        const char bq = '\\';
+        const char nl = '\n';
+        char c;
+
+        fputc(sq, stream);
+        while ((c = *src++)) {
+                if (c == nl) {
+                        fputc(bq, stream);
+                        fputc('n', stream);
+                        continue;
+                }
+                if (c == sq || c == bq)
+                        fputc(bq, stream);
+                fputc(c, stream);
+        }
+        fputc(sq, stream);
+}
+
+void tcl_quote_print(FILE *stream, const char *src)
+{
+        char c;
+
+        fputc('"', stream);
+        while ((c = *src++)) {
+                switch (c) {
+                case '[': case ']':
+                case '{': case '}':
+                case '$': case '\\': case '"':
+                        fputc('\\', stream);
+                default:
+                        fputc(c, stream);
+                        break;
+                case '\f':
+                        fputs("\\f", stream);
+                        break;
+                case '\r':
+                        fputs("\\r", stream);
+                        break;
+                case '\n':
+                        fputs("\\n", stream);
+                        break;
+                case '\t':
+                        fputs("\\t", stream);
+                        break;
+                case '\v':
+                        fputs("\\v", stream);
+                        break;
+                }
+        }
+        fputc('"', stream);
+}