已解决：Ubuntu系统下Darkice无法连接Shoutcast服务器问题排查

初始配置 #

我在Ubuntu系统中使用Darkice客户端尝试对接Shoutcast服务器，所用配置如下：

# 直播流会话通用配置
[general]
duration        = 0        # 编码时长，单位秒，0表示永久推流
bufferSecs      = 10       # 内部缓冲大小，单位秒
reconnect       = yes      # 断开连接后自动重连
realtime        = no       # 不使用POSIX实时优先级运行编码器
rtprio          = 3        # 实时线程调度优先级

# 音频输入配置
[input]
device           = hw:CARD=PCH,DEV=0
sampleRate      = 44100    # 采样率，可选11025、22050、44100
bitsPerSample   = 16       # 采样位深，推荐16
channel         = 2        # 声道数，1=单声道，2=立体声

# Shoutcast服务器连接配置
[shoutcast-0]
bitrateMode     = cbr
format          = mp3
bitrate         = 96
quality         = 1.0
server          = xxxxxxxxxxxxxxx
port            = 8020
password        = xxxxxxxxxxxxxxx
name            = Radio website
url             = https://www.mywebsite.it
genre           = live
public          = no

启动操作与故障现象 #

使用如下命令启动Darkice：

darkice -v 10 -c /etc/darkice-shoutcast.cfg

执行后仅输出如下日志，无明确报错，但服务器端没有收到直播流。同环境下使用BUTT工具可以正常连接该Shoutcast服务器，尝试将端口从8020替换为8021测试，仍无法成功连接。
启动日志内容：

DarkIce 1.4 live audio streamer, http://code.google.com/p/darkice/
Copyright (c) 2000-2007, Tyrell Hungary, http://tyrell.hu/
Copyright (c) 2008-2013, Akos Maroy and Rafael Diniz
This is free software, and you are welcome to redistribute it 
under the terms of The GNU General Public License version 3 or
any later version.

Using config file: /etc/darkice-shoutcast.cfg
18-May-2021 12:02:28 Using ALSA DSP input device: hw:CARD=PCH,DEV=0
18-May-2021 12:02:28 buffer size:  1764000
18-May-2021 12:02:28 encoding
18-May-2021 12:02:28 MultiThreadedConnector :: transfer, bytes 0
18-May-2021 12:02:28 MultiThreadedConnector :: ThreadData :: threadFunction, was (thread, priority, type):  0x5568a502c010 0 SCHED_OTHER
18-May-2021 12:02:28 MultiThreadedConnector :: ThreadData :: threadFunction, now is (thread, priority, type):  0x5568a502c010 0 SCHED_OTHER

排查过程 #

使用tcpdump抓包分析交互内容，发现服务器返回包中存在invalid password相关报错：

: Flags [P.], cksum 0xc379 (correct), seq 1:19, ack 3090, win 294, options [nop,nop,TS val 3348978428 ecr 531576376], length 18
E..F1O@.1.3'.}.......T.Jq.k.D......&.y.....
..Z...68Invalid Passwor

故障原因与修复方案 #

Darkice的配置解析逻辑对密码字段的格式要求严格，原配置中password字段等号前后的空格会被识别为密码的一部分，导致校验失败。
删除密码行等号前后的空格即可解决问题，修改后的配置如下：

[shoutcast-0]
bitrateMode     = cbr
format          = mp3
bitrate         = 96
quality         = 1.0
server          = xxxxxxxxxxxxxxx
port            = 8020
password=xxxxxxxxxxxxxxx
name            = Radio website
url             = https://www.mywebsite.it
genre           = live
public          = no

内容的提问来源于stack exchange，提问作者Miro Barsocchi