ftp: fix interrupt callback misuse

FTP protocol used interrupt callback to simulate nonblock
operation which is a misuse of this callback.

This commit make FTP protocol fully blocking and removes
invalid usage of interrutp callback

Also adds support for multiline responses delimited with dashes
(cherry picked from commit 247e658784ead984f96021acb9c95052ba599f26)

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

1 files changed, 32 insertions, 77 deletions

diff --git a/libavformat/ftp.c b/libavformat/ftp.c
index a256a25335..6358726034 100644
--- a/libavformat/ftp.c
+++ b/libavformat/ftp.c
@@ -27,6 +27,7 @@
 #include "os_support.h"
 #include "url.h"
 #include "libavutil/opt.h"
+#include "libavutil/bprint.h"
 
 #define CONTROL_BUFFER_SIZE 1024
 #define CREDENTIALS_BUFFER_SIZE 128
@@ -42,8 +43,6 @@ typedef enum {
 typedef struct {
     const AVClass *class;
     URLContext *conn_control;                    /**< Control connection */
-    int conn_control_block_flag;                 /**< Controls block/unblock mode of data connection */
-    AVIOInterruptCB conn_control_interrupt_cb;   /**< Controls block/unblock mode of data connection */
     URLContext *conn_data;                       /**< Data connection, NULL when not connected */
     uint8_t control_buffer[CONTROL_BUFFER_SIZE]; /**< Control connection buffer */
     uint8_t *control_buf_ptr, *control_buf_end;
@@ -77,18 +76,10 @@ static const AVClass ftp_context_class = {
     .version        = LIBAVUTIL_VERSION_INT,
 };
 
-static int ftp_conn_control_block_control(void *data)
-{
-    FTPContext *s = data;
-    return s->conn_control_block_flag;
-}
-
 static int ftp_getc(FTPContext *s)
 {
     int len;
     if (s->control_buf_ptr >= s->control_buf_end) {
-        if (s->conn_control_block_flag)
-            return AVERROR_EXIT;
         len = ffurl_read(s->conn_control, s->control_buffer, CONTROL_BUFFER_SIZE);
         if (len < 0) {
             return len;
@@ -106,12 +97,10 @@ static int ftp_get_line(FTPContext *s, char *line, int line_size)
 {
     int ch;
     char *q = line;
-    int ori_block_flag = s->conn_control_block_flag;
 
     for (;;) {
         ch = ftp_getc(s);
         if (ch < 0) {
-            s->conn_control_block_flag = ori_block_flag;
             return ch;
         }
         if (ch == '\n') {
@@ -119,35 +108,14 @@ static int ftp_get_line(FTPContext *s, char *line, int line_size)
             if (q > line && q[-1] == '\r')
                 q--;
             *q = '\0';
-
-            s->conn_control_block_flag = ori_block_flag;
             return 0;
         } else {
-            s->conn_control_block_flag = 0; /* line need to be finished */
             if ((q - line) < line_size - 1)
                 *q++ = ch;
         }
     }
 }
 
-static int ftp_flush_control_input(FTPContext *s)
-{
-    char buf[CONTROL_BUFFER_SIZE];
-    int err, ori_block_flag = s->conn_control_block_flag;
-
-    s->conn_control_block_flag = 1;
-    do {
-        err = ftp_get_line(s, buf, sizeof(buf));
-    } while (!err);
-
-    s->conn_control_block_flag = ori_block_flag;
-
-    if (err < 0 && err != AVERROR_EXIT)
-        return err;
-
-    return 0;
-}
-
 /*
  * This routine returns ftp server response code.
  * Server may send more than one response for a certain command, following priorities are used:
@@ -156,49 +124,46 @@ static int ftp_flush_control_input(FTPContext *s)
  */
 static int ftp_status(FTPContext *s, char **line, const int response_codes[])
 {
-    int err, i, result = 0, pref_code_found = 0, wait_count = 100;
+    int err, i, dash = 0, result = 0, code_found = 0;
     char buf[CONTROL_BUFFER_SIZE];
+    AVBPrint line_buffer;
 
-    /* Set blocking mode */
-    s->conn_control_block_flag = 0;
-    for (;;) {
+    if (line)
+        av_bprint_init(&line_buffer, 0, AV_BPRINT_SIZE_AUTOMATIC);
+
+    while (!code_found || dash) {
         if ((err = ftp_get_line(s, buf, sizeof(buf))) < 0) {
-            if (err == AVERROR_EXIT) {
-                if (!pref_code_found && wait_count--) {
-                    av_usleep(10000);
-                    continue;
-                }
-            }
-            return result;
+            av_bprint_finalize(&line_buffer, NULL);
+            return err;
         }
 
         av_log(s, AV_LOG_DEBUG, "%s\n", buf);
 
-        if (!pref_code_found) {
-            if (strlen(buf) < 3)
-                continue;
-
-            err = 0;
-            for (i = 0; i < 3; ++i) {
-                if (buf[i] < '0' || buf[i] > '9')
-                    continue;
-                err *= 10;
-                err += buf[i] - '0';
-            }
+        if (strlen(buf) < 4)
+            continue;
 
-            for (i = 0; response_codes[i]; ++i) {
-                if (err == response_codes[i]) {
-                    /* first code received. Now get all lines in non blocking mode */
-                    s->conn_control_block_flag = 1;
-                    pref_code_found = 1;
-                    result = err;
-                    if (line)
-                        *line = av_strdup(buf);
-                    break;
-                }
+        err = 0;
+        for (i = 0; i < 3; ++i) {
+            if (buf[i] < '0' || buf[i] > '9')
+                continue;
+            err *= 10;
+            err += buf[i] - '0';
+        }
+        dash = !!(buf[3] == '-');
+
+        for (i = 0; response_codes[i]; ++i) {
+            if (err == response_codes[i]) {
+                if (line)
+                    av_bprintf(&line_buffer, "%s", buf);
+                code_found = 1;
+                result = err;
+                break;
             }
         }
     }
+
+    if (line)
+        av_bprint_finalize(&line_buffer, line);
     return result;
 }
 
@@ -207,12 +172,6 @@ static int ftp_send_command(FTPContext *s, const char *command,
 {
     int err;
 
-    /* Flush control connection input to get rid of non relevant responses if any */
-    if ((err = ftp_flush_control_input(s)) < 0)
-        return err;
-
-    /* send command in blocking mode */
-    s->conn_control_block_flag = 0;
     if ((err = ffurl_write(s->conn_control, command, strlen(command))) < 0)
         return err;
     if (!err)
@@ -434,8 +393,6 @@ static int ftp_connect_control_connection(URLContext *h)
     FTPContext *s = h->priv_data;
     const int connect_codes[] = {220, 0};
 
-    s->conn_control_block_flag = 0;
-
     if (!s->conn_control) {
         ff_url_join(buf, sizeof(buf), "tcp", NULL,
                     s->hostname, s->server_control_port, NULL);
@@ -444,7 +401,7 @@ static int ftp_connect_control_connection(URLContext *h)
             av_dict_set(&opts, "timeout", opts_format, 0);
         } /* if option is not given, don't pass it and let tcp use its own default */
         err = ffurl_open(&s->conn_control, buf, AVIO_FLAG_READ_WRITE,
-                         &s->conn_control_interrupt_cb, &opts);
+                         &h->interrupt_callback, &opts);
         av_dict_free(&opts);
         if (err < 0) {
             av_log(h, AV_LOG_ERROR, "Cannot open control connection\n");
@@ -489,7 +446,7 @@ static int ftp_connect_data_connection(URLContext *h)
             snprintf(opts_format, sizeof(opts_format), "%d", s->rw_timeout);
             av_dict_set(&opts, "timeout", opts_format, 0);
         } /* if option is not given, don't pass it and let tcp use its own default */
-        err = ffurl_open(&s->conn_data, buf, AVIO_FLAG_READ_WRITE,
+        err = ffurl_open(&s->conn_data, buf, h->flags,
                          &h->interrupt_callback, &opts);
         av_dict_free(&opts);
         if (err < 0)
@@ -553,8 +510,6 @@ static int ftp_open(URLContext *h, const char *url, int flags)
     s->state = DISCONNECTED;
     s->filesize = -1;
     s->position = 0;
-    s->conn_control_interrupt_cb.opaque = s;
-    s->conn_control_interrupt_cb.callback = ftp_conn_control_block_control;
 
     av_url_split(proto, sizeof(proto),
                  s->credencials, sizeof(s->credencials),