ftp: reduce amount of realloc's done in cmdio_write

   text    data     bss     dec     hex filename
 808562     476    7864  816902   c7706 busybox_old
 808568     476    7864  816908   c770c busybox_unstripped

diff --git a/networking/ftpd.c b/networking/ftpd.c
index 4988ce02e3cdf752fcb7d842bc7f43cc9ce1e77d..b2d6ef2d24a1fa5f3f15cbfcebcca9faef61547c 100644 (file)
--- a/networking/ftpd.c
+++ b/networking/ftpd.c
@@ -102,7 +102,7 @@ struct globals {
        int pasv_listen_fd;
        int data_fd;
        off_t restart_pos;
-       char *ftp_cmp;
+       char *ftp_cmd;
        char *ftp_arg;
 #if ENABLE_FEATURE_FTP_WRITE
        char *rnfr_filename;
@@ -112,8 +112,9 @@ struct globals {
 #define G (*(struct globals*)&bb_common_bufsiz1)
 #define INIT_G() do { } while (0)
 
+
 static char *
-replace_text(const char *str, const char from, const char *to)
+escape_text(const char *prepend, const char *str, char from, const char *to, char append)
 {
        size_t retlen, remainlen, chunklen, tolen;
        const char *remain;
@@ -124,29 +125,27 @@ replace_text(const char *str, const char from, const char *to)
        tolen = strlen(to);
 
        /* Simply alloc strlen(str)*strlen(to). "to" is max 2 so it's ok */
-       ret = xmalloc(remainlen * tolen + 1);
-       retlen = 0;
+       retlen = strlen(prepend);
+       ret = xmalloc(retlen + remainlen * tolen + 1 + 1);
+       strcpy(ret, prepend);
 
        for (;;) {
-               found = strchr(remain, from);
-               if (found != NULL) {
-                       chunklen = found - remain;
+               found = strchrnul(remain, from);
+               chunklen = found - remain;
 
-                       /* Copy chunk which doesn't contain 'from' to ret */
-                       memcpy(&ret[retlen], remain, chunklen);
-                       retlen += chunklen;
+               /* Copy chunk which doesn't contain 'from' to ret */
+               memcpy(&ret[retlen], remain, chunklen);
+               retlen += chunklen;
 
+               if (*found != '\0') {
                        /* Now copy 'to' instead of 'from' */
                        memcpy(&ret[retlen], to, tolen);
                        retlen += tolen;
 
                        remain = found + 1;
                } else {
-                       /*
-                        * The last chunk. We are already sure that we have enough space
-                        * so we can use strcpy.
-                        */
-                       strcpy(&ret[retlen], remain);
+                       ret[retlen] = append;
+                       ret[retlen+1] = '\0';
                        break;
                }
        }
@@ -163,15 +162,12 @@ replace_char(char *str, char from, char to)
 static void
 cmdio_write(unsigned status, const char *str)
 {
-       char *escaped_str, *response;
+       char *response;
        int len;
 
        /* FTP allegedly uses telnet protocol for command link.
         * In telnet, 0xff is an escape char, and needs to be escaped: */
-       escaped_str = replace_text(str, '\xff', "\xff\xff");
-
-       response = xasprintf("%u%s\r", status, escaped_str);
-       free(escaped_str);
+       response = escape_text(utoa(status), str, '\xff', "\xff\xff", '\r');
 
        /* ?! does FTP send embedded LFs as NULs? wow */
        len = strlen(response);
@@ -206,17 +202,15 @@ cmdio_write_raw(const char *p_text)
 static void
 handle_pwd(void)
 {
-       char *cwd, *promoted_cwd, *response;
+       char *cwd, *response;
 
        cwd = xrealloc_getcwd_or_warn(NULL);
        if (cwd == NULL)
                cwd = xstrdup("");
 
        /* We have to promote each " to "" */
-       promoted_cwd = replace_text(cwd, '\"', "\"\"");
+       response = escape_text(" \"", cwd, '\"', "\"\"", '\"');
        free(cwd);
-       response = xasprintf(" \"%s\"", promoted_cwd);
-       free(promoted_cwd);
        cmdio_write(FTP_PWDOK, response);
        free(response);
 }
@@ -872,9 +866,9 @@ cmdio_get_cmd_and_arg(void)
        uint32_t cmdval;
        char *cmd;
 
-       free(G.ftp_cmp);
+       free(G.ftp_cmd);
        len = 8 * 1024; /* Paranoia. Peer may send 1 gigabyte long cmd... */
-       G.ftp_cmp = cmd = xmalloc_reads(STDIN_FILENO, NULL, &len);
+       G.ftp_cmd = cmd = xmalloc_reads(STDIN_FILENO, NULL, &len);
        if (!cmd)
                exit(0);