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execve c 函数中的 iptables 不接受标志

tag-icon • tag-icon iptables c
execve c 函数中的 iptables 不接受标志

当我跑步时

$ /usr/sbin/iptables -I INPUT -p tcp --dport 80 -j ACCEPT

从命令行它工作正常。但是当我编译并运行这段代码时

#include <unistd.h>
int main() {
    char *args[6];
    args[0] = "/usr/sbin/iptables";
    args[1] = "-I INPUT";
    args[2] = "-p tcp";
    args[3] = "--dport 80";
    args[4] = "-j ACCEPT";
    args[5] = NULL;
    execve(args[0], args, NULL);
}

我得到以下输出

$ ./code
iptables v1.4.6: unknown protocol ` tcp' specified
Try `iptables -h' or 'iptables --help' for more information.

我尝试删除空格

#include <unistd.h>
int main() {
    char *args[6];
    args[0] = "/usr/sbin/iptables";
    args[1] = "-I INPUT";
    args[2] = "-ptcp";
    args[3] = "--dport 80";
    args[4] = "-j ACCEPT";
    args[5] = NULL;
    execve(args[0], args, NULL);
}

我得到了

$./code
iptables v1.4.6: unknown option `--dport 80'
Try `iptables -h' or 'iptables --help' for more information.

有人可以帮我从这里出去吗？我究竟做错了什么？

这是帮助输出

$ iptables --help
iptables v1.4.6

Usage: iptables -[AD] chain rule-specification [options]
       iptables -I chain [rulenum] rule-specification [options]
       iptables -R chain rulenum rule-specification [options]
       iptables -D chain rulenum [options]
       iptables -[LS] [chain [rulenum]] [options]
       iptables -[FZ] [chain] [options]
       iptables -[NX] chain
       iptables -E old-chain-name new-chain-name
       iptables -P chain target [options]
       iptables -h (print this help information)

Commands:
Either long or short options are allowed.
  --append  -A chain        Append to chain
  --delete  -D chain        Delete matching rule from chain
  --delete  -D chain rulenum
                Delete rule rulenum (1 = first) from chain
  --insert  -I chain [rulenum]
                Insert in chain as rulenum (default 1=first)
  --replace -R chain rulenum
                Replace rule rulenum (1 = first) in chain
  --list    -L [chain [rulenum]]
                List the rules in a chain or all chains
  --list-rules -S [chain [rulenum]]
                Print the rules in a chain or all chains
  --flush   -F [chain]      Delete all rules in  chain or all chains
  --zero    -Z [chain [rulenum]]
                Zero counters in chain or all chains
  --new     -N chain        Create a new user-defined chain
  --delete-chain
            -X [chain]      Delete a user-defined chain
  --policy  -P chain target
                Change policy on chain to target
  --rename-chain
            -E old-chain new-chain
                Change chain name, (moving any references)
Options:
[!] --proto -p proto    protocol: by number or name, eg. `tcp'
[!] --source    -s address[/mask][...]
                source specification
[!] --destination -d address[/mask][...]
                destination specification
[!] --in-interface -i input name[+]
                network interface name ([+] for wildcard)
 --jump -j target
                target for rule (may load target extension)
  --goto      -g chain
                              jump to chain with no return
  --match   -m match
                extended match (may load extension)
  --numeric -n      numeric output of addresses and ports
[!] --out-interface -o output name[+]
                network interface name ([+] for wildcard)
  --table   -t table    table to manipulate (default: `filter')
  --verbose -v      verbose mode
  --line-numbers        print line numbers when listing
  --exact   -x      expand numbers (display exact values)
[!] --fragment  -f      match second or further fragments only
  --modprobe=<command>      try to insert modules using this command
  --set-counters PKTS BYTES set the counter during insert/append
[!] --version   -V      print package version.

答案1

您需要以与 shell 相同的方式拆分参数：

#include <unistd.h>
int main() {
    char *args[10];
    int i = 0;
    args[i++] = "/usr/sbin/iptables";
    args[i++] = "-I";
    args[i++] = "INPUT";
    args[i++] = "-p";
    args[i++] = "tcp";
    args[i++] = "--dport";
    args[i++] = "80";
    args[i++] = "-j";
    args[i++] = "ACCEPT";
    args[i++] = NULL;
    execve(args[0], args, NULL);
}

外壳裂开全部空间。

答案2

标志和它们的参数应该是分开的：

int main() {
    char *args[] = {
      "/usr/sbin/iptables",
      "-I", "INPUT",
      "-ptcp",
      "--dport", "80",
      "-j", "ACCEPT",
      NULL
    };
...
}

对于选项和选项参数可以作为单个参数给出的命令，它们之间不应有空格（例如，tail和），或者根据命令-n6使用分隔符，例如和。=grep--color=always

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