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Merge pull request #1559 from everything411/shellspawn-zombie
Correctly handle the shellspawn zombie
authored by
CuriousTommy
and committed by
GitHub
a458d15d
d2108447
+14
-6
+14
-6
src/shellspawn/shellspawn.c
+14
-6
src/shellspawn/shellspawn.c
···
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#define DBG 0
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int g_serverSocket = -1;
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struct sigaction sigchld_oldaction;
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void setupSocket(void);
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void listenForConnections(void);
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void spawnShell(int fd);
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void setupSigchild(void);
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void restoreSigchild(void);
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void reapAll(void);
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int main(int argc, const char** argv)
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{
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// in order to read the exit status of the process,
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// we have to allow it to become a zombie, which is prevented
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// when we set the SIGCHLD signal to SA_NOCLDWAIT
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//setupSigchild();
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// shellspawn (daemon) --fork()--> shellspawn (child) --fork()--> exec /bin/bash
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// in order to read the exit status of the shell process,
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// we have to allow it to become a zombie, therefore we need to
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// restore the sigaction of SIGCHLD of the child shellspawn
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setupSigchild();
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setupSocket();
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listenForConnections();
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···
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if (fork() == 0)
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{
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restoreSigchild();
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fcntl(sock, F_SETFD, FD_CLOEXEC);
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spawnShell(sock);
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exit(EXIT_SUCCESS);
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else
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{
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close(sock);
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reapAll();
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}
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}
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}
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.sa_handler = SIG_DFL,
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.sa_flags = SA_NOCLDWAIT
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};
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sigaction(SIGCHLD, &sigchld_action, NULL);
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sigaction(SIGCHLD, &sigchld_action, &sigchld_oldaction);
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}
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void restoreSigchild(void)
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{
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sigaction(SIGCHLD, &sigchld_oldaction, NULL);
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}
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void reapAll(void)