ftpd: further code shrink

function                                             old     new   delta      
port_pasv_cleanup                                      -      50     +50      
replace_char                                           -      30     +30      
ftp_write_str_common                                 102     104      +2
handle_dir_common                                    209     204      -5
ftpd_main                                           1990    1970     -20
port_cleanup                                          23       -     -23
pasv_cleanup                                          28       -     -28
handle_upload_common                                 320     273     -47
------------------------------------------------------------------------------
(add/remove: 2/2 grow/shrink: 1/3 up/down: 82/-123)           Total: -41 bytes

1 files changed, 185 insertions, 192 deletions

diff --git a/networking/ftpd.c b/networking/ftpd.c
index 6289edf0c..404bc98c3 100644
--- a/networking/ftpd.c
+++ b/networking/ftpd.c
@@ -9,6 +9,8 @@
  *
  * Options:
  * -w   - enable FTP write commands
+ *
+ * TODO: implement "421 Timeout" thingy (alarm(60) while waiting for a cmd).
  */
 
 #include "libbb.h"
@@ -98,7 +100,7 @@ struct globals {
         int data_fd;
         off_t restart_pos;
         char *ftp_cmp;
-        const char *ftp_arg;
+        char *ftp_arg;
 #if ENABLE_FEATURE_FTP_WRITE
         char *rnfr_filename;
 #endif
@@ -156,22 +158,25 @@ replace_char(char *str, char from, char to)
 }
 
 static void
-ftp_write_str_common(unsigned int status, const char *str, char sep)
+ftp_write_str_common(unsigned status, const char *str, char sep)
 {
         char *escaped_str, *response;
-        size_t len;
+        int len;
 
-        escaped_str = replace_text(str, '\377', "\377\377");
+        /* 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%c%s\r\n", status, sep, escaped_str);
+        response = xasprintf("%u%c%s\r", status, sep, escaped_str);
         free(escaped_str);
 
+        /* ?! does FTP send embedded LFs as NULs? wow */
         len = strlen(response);
         replace_char(response, '\n', '\0');
 
-        /* Change trailing '\0' back to '\n' */
-        response[len - 1] = '\n';
+        response[len++] = '\n'; /* tack on trailing '\n' */
         xwrite(STDIN_FILENO, response, len);
+        free(response);
 }
 
 static void
@@ -198,35 +203,68 @@ cmdio_write_raw(const char *p_text)
         xwrite_str(STDIN_FILENO, p_text);
 }
 
-static uint32_t
-cmdio_get_cmd_and_arg(void)
+static void
+handle_pwd(void)
 {
-        size_t len;
-        uint32_t cmdval;
-        char *cmd;
+        char *cwd, *promoted_cwd, *response;
 
-        free(G.ftp_cmp);
-        len = 8 * 1024; /* Paranoia. Peer may send 1 gigabyte long cmd... */
-        G.ftp_cmp = cmd = xmalloc_reads(STDIN_FILENO, NULL, &len);
-        if (!cmd)
-                exit(0);
+        cwd = xrealloc_getcwd_or_warn(NULL);
+        if (cwd == NULL)
+                cwd = xstrdup("");
 
-        len = strlen(cmd) - 1;
-        while (len >= 0 && cmd[len] == '\r') {
-                cmd[len] = '\0';
-                len--;
+        /* We have to promote each " to "" */
+        promoted_cwd = replace_text(cwd, '\"', "\"\"");
+        free(cwd);
+        response = xasprintf("\"%s\"", promoted_cwd);
+        free(promoted_cwd);
+        cmdio_write(FTP_PWDOK, response);
+        free(response);
+}
+
+static void
+handle_cwd(void)
+{
+        if (!G.ftp_arg || chdir(G.ftp_arg) != 0) {
+                cmdio_write(FTP_FILEFAIL, "Can't change directory");
+                return;
         }
+        cmdio_write_ok(FTP_CWDOK);
+}
 
-        G.ftp_arg = strchr(cmd, ' ');
-        if (G.ftp_arg != NULL) {
-                *(char *)G.ftp_arg = '\0';
-                G.ftp_arg++;
+static void
+handle_cdup(void)
+{
+        G.ftp_arg = (char*)"..";
+        handle_cwd();
+}
+
+static void
+handle_type(void)
+{
+        if (G.ftp_arg
+         && (  ((G.ftp_arg[0] | 0x20) == 'i' && G.ftp_arg[1] == '\0')
+            || !strcasecmp(G.ftp_arg, "L8")
+            || !strcasecmp(G.ftp_arg, "L 8")
+            )
+        ) {
+                cmdio_write_ok(FTP_TYPEOK);
+        } else {
+                cmdio_write(FTP_BADCMD, "Unrecognised TYPE command");
         }
-        cmdval = 0;
-        while (*cmd)
-                cmdval = (cmdval << 8) + ((unsigned char)*cmd++ & (unsigned char)~0x20);
+}
 
-        return cmdval;
+static void
+handle_help(void)
+{
+        cmdio_write_hyphen(FTP_HELP, "Recognized commands:");
+        cmdio_write_raw(" ALLO CDUP CWD HELP LIST\r\n"
+                        " MODE NLST NOOP PASS PASV PORT PWD QUIT\r\n"
+                        " REST RETR STAT STRU SYST TYPE USER\r\n"
+#if ENABLE_FEATURE_FTP_WRITE
+                        " APPE DELE MKD RMD RNFR RNTO STOR STOU\r\n"
+#endif
+        );
+        cmdio_write(FTP_HELP, "Help OK");
 }
 
 static void
@@ -265,7 +303,7 @@ ftpdataio_get_port_fd(void)
 {
         int remote_fd;
 
-        /* Do we want die or print error to client? */
+        /* Do we want to die or print error to client? */
         remote_fd = xconnect_stream(G.port_addr);
 
         init_data_sock_params(remote_fd);
@@ -289,16 +327,16 @@ ftpdataio_dispose_transfer_fd(void)
         G.data_fd = -1;
 }
 
-static int
+static inline int
 port_active(void)
 {
-        return (G.port_addr != NULL) ? 1: 0;
+        return (G.port_addr != NULL);
 }
 
-static int
+static inline int
 pasv_active(void)
 {
-        return (G.pasv_listen_fd != -1) ? 1 : 0;
+        return (G.pasv_listen_fd > STDOUT_FILENO);
 }
 
 static int
@@ -318,41 +356,6 @@ get_remote_transfer_fd(const char *p_status_msg)
         return remote_fd;
 }
 
-static void
-handle_pwd(void)
-{
-        char *cwd, *promoted_cwd, *response;
-
-        cwd = xrealloc_getcwd_or_warn(NULL);
-        if (cwd == NULL)
-                cwd = xstrdup("");
-
-        /* We have to promote each " to "" */
-        promoted_cwd = replace_text(cwd, '\"', "\"\"");
-        free(cwd);
-        response = xasprintf("\"%s\"", promoted_cwd);
-        free(promoted_cwd);
-        cmdio_write(FTP_PWDOK, response);
-        free(response);
-}
-
-static void
-handle_cwd(void)
-{
-        if (!G.ftp_arg || chdir(G.ftp_arg) != 0) {
-                cmdio_write(FTP_FILEFAIL, "Can't change directory");
-                return;
-        }
-        cmdio_write_ok(FTP_CWDOK);
-}
-
-static void
-handle_cdup(void)
-{
-        G.ftp_arg = "..";
-        handle_cwd();
-}
-
 static int
 data_transfer_checks_ok(void)
 {
@@ -365,15 +368,10 @@ data_transfer_checks_ok(void)
 }
 
 static void
-port_cleanup(void)
+port_pasv_cleanup(void)
 {
         free(G.port_addr);
         G.port_addr = NULL;
-}
-
-static void
-pasv_cleanup(void)
-{
         if (G.pasv_listen_fd > STDOUT_FILENO)
                 close(G.pasv_listen_fd);
         G.pasv_listen_fd = -1;
@@ -385,10 +383,10 @@ handle_pasv(void)
         int bind_retries = 10;
         unsigned short port;
         enum { min_port = 1024, max_port = 65535 };
-        char *addr, *wire_addr, *response;
+        char *addr, *response;
+
+        port_pasv_cleanup();
 
-        pasv_cleanup();
-        port_cleanup();
         G.pasv_listen_fd = xsocket(G.local_addr->u.sa.sa_family, SOCK_STREAM, 0);
         setsockopt_reuseaddr(G.pasv_listen_fd);
 
@@ -413,14 +411,13 @@ handle_pasv(void)
                 bb_error_msg_and_die("can't create pasv socket");
 
         addr = xmalloc_sockaddr2dotted_noport(&G.local_addr->u.sa);
-        wire_addr = replace_text(addr, '.', ",");
-        free(addr);
+        replace_char(addr, '.', ',');
 
         response = xasprintf("Entering Passive Mode (%s,%u,%u)",
-                        wire_addr, (int)(port >> 8), (int)(port & 255));
+                        addr, (int)(port >> 8), (int)(port & 255));
+        free(addr);
 
         cmdio_write(FTP_PASVOK, response);
-        free(wire_addr);
         free(response);
 }
 
@@ -428,37 +425,35 @@ static void
 handle_port(void)
 {
         unsigned short port;
-        char *raw = NULL, *port_part;
+        char *raw, *port_part;
         len_and_sockaddr *lsa = NULL;
 
-        pasv_cleanup();
-        port_cleanup();
+        port_pasv_cleanup();
 
-        if (G.ftp_arg == NULL)
-                goto bail;
+        raw = G.ftp_arg;
 
-        raw = replace_text(G.ftp_arg, ',', ".");
+        /* buglets:
+         * xatou16 will accept wrong input,
+         * xatou16 will exit instead of generating error to peer
+         */
 
-        port_part = strrchr(raw, '.');
+        port_part = strrchr(raw, ',');
         if (port_part == NULL)
                 goto bail;
-
         port = xatou16(&port_part[1]);
         *port_part = '\0';
 
-        port_part = strrchr(raw, '.');
+        port_part = strrchr(raw, ',');
         if (port_part == NULL)
                 goto bail;
-
         port |= xatou16(&port_part[1]) << 8;
         *port_part = '\0';
 
+        replace_char(raw, ',', '.');
         lsa = xdotted2sockaddr(raw, port);
 
-bail:
-        free(raw);
-
         if (lsa == NULL) {
+ bail:
                 cmdio_write(FTP_BADCMD, "Illegal PORT command");
                 return;
         }
@@ -528,10 +523,10 @@ handle_retr(void)
         else
                 cmdio_write_ok(FTP_TRANSFEROK);
 
-port_pasv_cleanup_out:
-        port_cleanup();
-        pasv_cleanup();
-file_close_out:
+ port_pasv_cleanup_out:
+        port_pasv_cleanup();
+
+ file_close_out:
         close(opened_file);
 }
 
@@ -691,12 +686,11 @@ handle_dir_common(int full_details, int stat_cmd)
         } else
                 write_dirstats(fd, ".", full_details);
 
-bail:
+ bail:
         /* Well, if we can't open directory/file it doesn't matter */
         if (!stat_cmd) {
                 ftpdataio_dispose_transfer_fd();
-                pasv_cleanup();
-                port_cleanup();
+                port_pasv_cleanup();
                 cmdio_write_ok(FTP_TRANSFEROK);
         } else
                 cmdio_write_ok(FTP_STATFILE_OK);
@@ -728,98 +722,8 @@ handle_stat(void)
         cmdio_write_ok(FTP_STATOK);
 }
 
-static void
-handle_type(void)
-{
-        if (G.ftp_arg
-         && (  ((G.ftp_arg[0] | 0x20) == 'i' && G.ftp_arg[1] == '\0')
-            || !strcasecmp(G.ftp_arg, "L8")
-            || !strcasecmp(G.ftp_arg, "L 8")
-            )
-        ) {
-                cmdio_write_ok(FTP_TYPEOK);
-        } else {
-                cmdio_write(FTP_BADCMD, "Unrecognised TYPE command");
-        }
-}
-
-static void
-handle_help(void)
-{
-        cmdio_write_hyphen(FTP_HELP, "Recognized commands:");
-        cmdio_write_raw(" ALLO CDUP CWD HELP LIST\r\n"
-                        " MODE NLST NOOP PASS PASV PORT PWD QUIT\r\n"
-                        " REST RETR STAT STRU SYST TYPE USER\r\n"
-#if ENABLE_FEATURE_FTP_WRITE
-                        " APPE DELE MKD RMD RNFR RNTO STOR STOU\r\n"
-#endif
-        );
-        cmdio_write(FTP_HELP, "Help OK");
-}
-
 #if ENABLE_FEATURE_FTP_WRITE
 static void
-handle_upload_common(int is_append, int is_unique)
-{
-        char *tempname = NULL;
-        int trans_ret;
-        int new_file_fd;
-        int remote_fd;
-        off_t offset = G.restart_pos;
-
-        G.restart_pos = 0;
-        if (!G.ftp_arg || !data_transfer_checks_ok())
-                return;
-
-        if (is_unique) {
-                tempname = xstrdup("FILE: uniq.XXXXXX");
-                /*
-                 * XXX Use mkostemp here? vsftpd opens file with O_CREAT, O_WRONLY, 
-                 * O_APPEND and O_EXCL flags...
-                 */
-                new_file_fd = mkstemp(tempname + 6);
-        } else {
-                /* XXX Do we need check if ftp_arg != NULL? */
-                if (!is_append && offset == 0)
-                        new_file_fd = open(G.ftp_arg, O_CREAT | O_WRONLY | O_APPEND | O_NONBLOCK | O_TRUNC, 0666);
-                else
-                        new_file_fd = open(G.ftp_arg, O_CREAT | O_WRONLY | O_APPEND | O_NONBLOCK, 0666);
-        }
-
-        if (new_file_fd < 0) {
-                cmdio_write(FTP_UPLOADFAIL, "Can't create file");
-                return;
-        }
-
-        if (!is_append && offset != 0) {
-                /* warning, allows seek past end of file! Check for seek > size? */
-                xlseek(new_file_fd, offset, SEEK_SET);
-        }
-
-        if (tempname) {
-                remote_fd = get_remote_transfer_fd(tempname);
-                free(tempname);
-        } else
-                remote_fd = get_remote_transfer_fd("Ok to send data");
-
-        if (remote_fd < 0)
-                goto bail;
-
-        trans_ret = bb_copyfd_eof(remote_fd, new_file_fd);
-        ftpdataio_dispose_transfer_fd();
-
-        if (trans_ret < 0)
-                cmdio_write(FTP_BADSENDFILE, "Failure writing to local file");
-        else
-                cmdio_write_ok(FTP_TRANSFEROK);
-
-bail:
-        port_cleanup();
-        pasv_cleanup();
-        close(new_file_fd);
-}
-
-static void
 handle_mkd(void)
 {
         if (!G.ftp_arg || mkdir(G.ftp_arg, 0777) != 0) {
@@ -892,6 +796,62 @@ handle_rnto(void)
 }
 
 static void
+handle_upload_common(int is_append, int is_unique)
+{
+        char *tempname = NULL;
+        int trans_ret;
+        int local_file_fd;
+        int remote_fd;
+        off_t offset;
+
+        offset = G.restart_pos;
+        G.restart_pos = 0;
+
+        if (!data_transfer_checks_ok())
+                return;
+
+        local_file_fd = -1;
+        if (is_unique) {
+                tempname = xstrdup("FILE: uniq.XXXXXX");
+                local_file_fd = mkstemp(tempname + 6);
+        } else if (G.ftp_arg) {
+                int flags = O_WRONLY | O_CREAT | O_TRUNC;
+                if (is_append)
+                        flags = O_WRONLY | O_CREAT | O_APPEND;
+                if (offset)
+                        flags = O_WRONLY | O_CREAT;
+                local_file_fd = open(G.ftp_arg, flags, 0666);
+        }
+        if (local_file_fd < 0) {
+                cmdio_write(FTP_UPLOADFAIL, "Can't create file");
+                return;
+        }
+
+        /* TODO: paranoia: fstat it, refuse to do anything if it's not a regular file */
+
+        if (offset)
+                xlseek(local_file_fd, offset, SEEK_SET);
+
+        remote_fd = get_remote_transfer_fd(tempname ? tempname : "Ok to send data");
+        free(tempname);
+
+        if (remote_fd < 0)
+                goto bail;
+
+        trans_ret = bb_copyfd_eof(remote_fd, local_file_fd);
+        ftpdataio_dispose_transfer_fd();
+
+        if (trans_ret < 0)
+                cmdio_write(FTP_BADSENDFILE, "Failure writing to local file");
+        else
+                cmdio_write_ok(FTP_TRANSFEROK);
+
+ bail:
+        port_pasv_cleanup();
+        close(local_file_fd);
+}
+
+static void
 handle_stor(void)
 {
         handle_upload_common(0, 0);
@@ -900,16 +860,49 @@ handle_stor(void)
 static void
 handle_appe(void)
 {
+        G.restart_pos = 0;
         handle_upload_common(1, 0);
 }
 
 static void
 handle_stou(void)
 {
+        G.restart_pos = 0;
         handle_upload_common(0, 1);
 }
 #endif /* ENABLE_FEATURE_FTP_WRITE */
 
+static uint32_t
+cmdio_get_cmd_and_arg(void)
+{
+        size_t len;
+        uint32_t cmdval;
+        char *cmd;
+
+        free(G.ftp_cmp);
+        len = 8 * 1024; /* Paranoia. Peer may send 1 gigabyte long cmd... */
+        G.ftp_cmp = cmd = xmalloc_reads(STDIN_FILENO, NULL, &len);
+        if (!cmd)
+                exit(0);
+
+        len = strlen(cmd) - 1;
+        while (len >= 0 && cmd[len] == '\r') {
+                cmd[len] = '\0';
+                len--;
+        }
+
+        G.ftp_arg = strchr(cmd, ' ');
+        if (G.ftp_arg != NULL) {
+                *G.ftp_arg = '\0';
+                G.ftp_arg++;
+        }
+        cmdval = 0;
+        while (*cmd)
+                cmdval = (cmdval << 8) + ((unsigned char)*cmd++ & (unsigned char)~0x20);
+
+        return cmdval;
+}
+
 int ftpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int ftpd_main(int argc UNUSED_PARAM, char **argv)
 {