srt: move common code to single file

1. code can be shared between access/srt.c and access_output/srt.c
2. created a URL parser for SRT parameters stored in URL

Signed-off-by: Thomas Guillem <thomas@gllm.fr>

modules/access/Makefile.am

@@ -423,7 +423,7 @@ EXTRA_LTLIBRARIES += libaccess_mtp_plugin.la
 
 ### SRT ###
 
-libaccess_srt_plugin_la_SOURCES = access/srt.c dummy.cpp
+libaccess_srt_plugin_la_SOURCES = access/srt.c access/srt_common.c access/srt_common.h dummy.cpp
 libaccess_srt_plugin_la_CFLAGS = $(AM_CFLAGS) $(SRT_CFLAGS)
 libaccess_srt_plugin_la_CPPFLAGS = $(AM_CPPFLAGS) $(SRT_CPPFLAGS)
 libaccess_srt_plugin_la_LIBADD = $(SRT_LIBS)

modules/access/srt_common.c

+/*****************************************************************************
+ * srt_common.c: SRT (Secure Reliable Transport) access module
+ *****************************************************************************
+ *
+ * Copyright (C) 2019, Haivision Systems Inc.
+ *
+ * Author: Aaron Boxer <aaron.boxer@collabora.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+#include "srt_common.h"
+
+const char * const srt_key_length_names[] = { N_( "16 bytes" ), N_(
+        "24 bytes" ), N_( "32 bytes" ), };
+
+typedef struct parsed_param {
+    char *key;
+    char *val;
+} parsed_param_t;
+
+static inline char*
+find(char *str, char find)
+{
+    str = strchr( str, find );
+    return str != NULL ? str + 1 : NULL;
+}
+
+/**
+ * Parse a query string into an array of key/value structs.
+ *
+ * The query string should be a null terminated string of parameters separated
+ * by a delimiter. Each parameter are checked for the equal sign character.
+ * If it appears in the parameter, it will be used as a null terminator
+ * and the part that comes after it will be the value of the parameter.
+ *
+ *
+ * param: query:         the query string to parse. The string will be modified.
+ * param: delimiter:      the character that separates the key/value pairs
+ *                      from each other.
+ * param: params:       an array of parsed_param structs to hold the result.
+ * param: max_params:     maximum number of parameters to parse.
+ *
+ * Return:                the number of parsed items. -1 if there was an error.
+ */
+static int srt_url_parse_query(char *query, const char* delimiter,
+        parsed_param_t *params, int max_params)
+{
+    int i = 0;
+    char *token = NULL;
+
+    if (!query || *query == '\0')
+        return -1;
+    if (!params || max_params == 0)
+        return 0;
+
+    token = strtok( query, delimiter );
+    while (token != NULL && i < max_params) {
+        params[i].key = token;
+        params[i].val = NULL;
+        if ((params[i].val = strchr( params[i].key, '=' )) != NULL) {
+            size_t val_len = strlen( params[i].val );
+
+            /* make key into a zero-delimited string */
+            *(params[i].val) = '\0';
+
+            /* make sure val is not empty */
+            if (val_len > 1) {
+                params[i].val++;
+
+                /* make sure key is not empty */
+                if (params[i].key[0])
+                    i++;
+            };
+        }
+        token = strtok( NULL, delimiter );
+    }
+    return i;
+}
+
+bool srt_parse_url(char* url, srt_params_t* params)
+{
+    char* query = NULL;
+    struct parsed_param local_params[32];
+    int num_params = 0;
+    int i = 0;
+    bool rc = false;
+
+    if (!url || !url[0] || !params)
+        return false;
+
+    /* initialize params */
+    params->latency = -1;
+    params->passphrase = NULL;
+    params->key_length = -1;
+    params->payload_size = -1;
+    params->bandwidth_overhead_limit = -1;
+
+    /* Parse URL parameters */
+    query = find( url, '?' );
+    if (query) {
+        num_params = srt_url_parse_query( query, "&", local_params,
+                sizeof(local_params) / sizeof(struct parsed_param) );
+        if (num_params > 0) {
+            rc = true;
+            for (i = 0; i < num_params; ++i) {
+                char* val = local_params[i].val;
+                if (!val)
+                    continue;
+
+                if (strcmp( local_params[i].key, SRT_PARAM_LATENCY ) == 0) {
+                    int temp = atoi( val );
+                    if (temp >= 0)
+                        params->latency = temp;
+                } else if (strcmp( local_params[i].key, SRT_PARAM_PASSPHRASE )
+                        == 0) {
+                    params->passphrase = val;
+                } else if (strcmp( local_params[i].key, SRT_PARAM_PAYLOAD_SIZE )
+                        == 0) {
+                    int temp = atoi( val );
+                    if (temp >= 0)
+                        params->payload_size = temp;
+                } else if (strcmp( local_params[i].key, SRT_PARAM_KEY_LENGTH )
+                        == 0) {
+                    int temp = atoi( val );
+                    if (temp == srt_key_lengths[0] || temp == srt_key_lengths[1]
+                            || temp == srt_key_lengths[2]) {
+                        params->key_length = temp;
+                    }
+                } else if (strcmp( local_params[i].key,
+                SRT_PARAM_BANDWIDTH_OVERHEAD_LIMIT ) == 0) {
+                    int temp = atoi( val );
+                    if (temp >= 0)
+                        params->bandwidth_overhead_limit = temp;
+
+                }
+            }
+        }
+    }
+
+    return rc;
+}
+
+int srt_set_socket_option(vlc_object_t *this, const char *srt_param,
+        SRTSOCKET u, SRT_SOCKOPT opt, const void *optval, int optlen)
+{
+    int stat = 0;
+
+    stat = srt_setsockopt( u, 0, opt, optval, optlen );
+    if (stat)
+    msg_Err( this, "Failed to set socket option %s (reason: %s)", srt_param,
+            srt_getlasterror_str() );
+
+    return stat;
+}
+

modules/access/srt_common.h

+/*****************************************************************************
+ * srt_common.h: SRT (Secure Reliable Transport) access module
+ *****************************************************************************
+ *
+ * Copyright (C) 2019, Haivision Systems Inc.
+ *
+ * Author: Aaron Boxer <aaron.boxer@collabora.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+#ifndef SRT_COMMON_H
+#define SRT_COMMON_H 1
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <vlc_common.h>
+#include <srt/srt.h>
+
+
+/* SRT parameter names */
+#define SRT_PARAM_LATENCY                     "latency"
+#define SRT_PARAM_PASSPHRASE                  "passphrase"
+#define SRT_PARAM_PAYLOAD_SIZE                "payload-size"
+#define SRT_PARAM_BANDWIDTH_OVERHEAD_LIMIT    "bandwidth-overhead-limit"
+#define SRT_PARAM_CHUNK_SIZE                  "chunk-size"
+#define SRT_PARAM_POLL_TIMEOUT                "poll-timeout"
+#define SRT_PARAM_KEY_LENGTH                  "key-length"
+
+
+#define SRT_DEFAULT_BANDWIDTH_OVERHEAD_LIMIT 25
+/* libsrt defines default packet size as 1316 internally
+ * so srt module takes same value. */
+#define SRT_DEFAULT_CHUNK_SIZE SRT_LIVE_DEF_PLSIZE
+/* libsrt tutorial uses 9000 as a default binding port */
+#define SRT_DEFAULT_PORT 9000
+/* Minimum/Maximum chunks to allow reading at a time from libsrt */
+#define SRT_MIN_CHUNKS_TRYREAD 10
+#define SRT_MAX_CHUNKS_TRYREAD 100
+/* The default timeout is -1 (infinite) */
+#define SRT_DEFAULT_POLL_TIMEOUT -1
+/* The default latency which srt library uses internally */
+#define SRT_DEFAULT_LATENCY       SRT_LIVE_DEF_LATENCY_MS
+#define SRT_DEFAULT_PAYLOAD_SIZE  SRT_LIVE_DEF_PLSIZE
+/* Crypto key length in bytes. */
+#define SRT_KEY_LENGTH_TEXT N_("Crypto key length in bytes")
+#define SRT_DEFAULT_KEY_LENGTH 16
+static const int srt_key_lengths[] = { 16, 24, 32, };
+
+extern const char * const srt_key_length_names[];
+
+typedef struct srt_params {
+    int latency;
+    const char* passphrase;
+    int key_length;
+    int payload_size;
+    int bandwidth_overhead_limit;
+} srt_params_t;
+
+bool srt_parse_url(char* url, srt_params_t* params);
+
+int srt_set_socket_option(vlc_object_t *this, const char *srt_param,
+        SRTSOCKET u, SRT_SOCKOPT opt, const void *optval, int optlen);
+
+#endif

modules/access_output/Makefile.am

@@ -27,7 +27,7 @@ access_out_LTLIBRARIES += $(LTLIBaccess_output_shout)
 EXTRA_LTLIBRARIES += libaccess_output_shout_plugin.la
 
 ### SRT ###
-libaccess_output_srt_plugin_la_SOURCES = access_output/srt.c dummy.cpp
+libaccess_output_srt_plugin_la_SOURCES = access_output/srt.c access/srt_common.c access/srt_common.h dummy.cpp
 libaccess_output_srt_plugin_la_CFLAGS = $(AM_CFLAGS) $(SRT_CFLAGS)
 libaccess_output_srt_plugin_la_CPPFLAGS = $(AM_CPPFLAGS) $(SRT_CPPFLAGS)
 libaccess_output_srt_plugin_la_LIBADD = $(SRT_LIBS)

po/POTFILES.in

@@ -213,6 +213,7 @@ modules/access/shm.c
 modules/access/smb_common.h
 modules/access/smb2.c
 modules/access/srt.c
+modules/access/srt_common.c
 modules/access/tcp.c
 modules/access/timecode.c
 modules/access/udp.c