X-Git-Url: https://arthur.barton.de/gitweb/?a=blobdiff_plain;f=src%2Fpopen.c;h=8448b7311d18049b185f686b2b92a2abb00fa527;hb=909e26f825bc1f6f907231761412c885331fec7e;hp=ab064d48d95ad09c90ed10d3cb43032bb3113e39;hpb=037bbc245f57e45f9e6f56c705957e38586d7218;p=netdata.git diff --git a/src/popen.c b/src/popen.c old mode 100755 new mode 100644 index ab064d48..8448b731 --- a/src/popen.c +++ b/src/popen.c @@ -1,130 +1,203 @@ -#include -#include -#include -#include -#include +#include "common.h" + +/* +struct mypopen { + pid_t pid; + FILE *fp; + struct mypopen *next; + struct mypopen *prev; +}; + +static struct mypopen *mypopen_root = NULL; + +static void mypopen_add(FILE *fp, pid_t *pid) { + struct mypopen *mp = malloc(sizeof(struct mypopen)); + if(!mp) { + fatal("Cannot allocate %zu bytes", sizeof(struct mypopen)) + return; + } + + mp->fp = fp; + mp->pid = pid; + mp->next = popen_root; + mp->prev = NULL; + if(mypopen_root) mypopen_root->prev = mp; + mypopen_root = mp; +} + +static void mypopen_del(FILE *fp) { + struct mypopen *mp; -#include "log.h" -#include "popen.h" + for(mp = mypopen_root; mp; mp = mp->next) + if(mp->fd == fp) break; + if(!mp) error("Cannot find mypopen() file pointer in open childs."); + else { + if(mp->next) mp->next->prev = mp->prev; + if(mp->prev) mp->prev->next = mp->next; + if(mypopen_root == mp) mypopen_root = mp->next; + free(mp); + } +} +*/ #define PIPE_READ 0 #define PIPE_WRITE 1 FILE *mypopen(const char *command, pid_t *pidptr) { - int pipefd[2]; - - if(pipe(pipefd) == -1) return NULL; - - int pid = fork(); - if(pid == -1) { - close(pipefd[PIPE_READ]); - close(pipefd[PIPE_WRITE]); - return NULL; - } - if(pid != 0) { - // the parent - *pidptr = pid; - close(pipefd[PIPE_WRITE]); - FILE *fp = fdopen(pipefd[PIPE_READ], "r"); - return(fp); - } - // the child - - // close all files - int i; - for(i = sysconf(_SC_OPEN_MAX); i > 0; i--) - if(i != STDIN_FILENO && i != STDERR_FILENO && i != pipefd[PIPE_WRITE]) close(i); - - // move the pipe to stdout - if(pipefd[PIPE_WRITE] != STDOUT_FILENO) { - dup2(pipefd[PIPE_WRITE], STDOUT_FILENO); - close(pipefd[PIPE_WRITE]); - } + int pipefd[2]; + + if(pipe(pipefd) == -1) return NULL; + + int pid = fork(); + if(pid == -1) { + close(pipefd[PIPE_READ]); + close(pipefd[PIPE_WRITE]); + return NULL; + } + if(pid != 0) { + // the parent + *pidptr = pid; + close(pipefd[PIPE_WRITE]); + FILE *fp = fdopen(pipefd[PIPE_READ], "r"); + /*mypopen_add(fp, pid);*/ + return(fp); + } + // the child + + // close all files + int i; + for(i = (int) (sysconf(_SC_OPEN_MAX) - 1); i > 0; i--) + if(i != STDIN_FILENO && i != STDERR_FILENO && i != pipefd[PIPE_WRITE]) close(i); + + // move the pipe to stdout + if(pipefd[PIPE_WRITE] != STDOUT_FILENO) { + dup2(pipefd[PIPE_WRITE], STDOUT_FILENO); + close(pipefd[PIPE_WRITE]); + } #ifdef DETACH_PLUGINS_FROM_NETDATA - // this was an attempt to detach the child and use the suspend mode charts.d - // unfortunatelly it does not work as expected. + // this was an attempt to detach the child and use the suspend mode charts.d + // unfortunatelly it does not work as expected. + + // fork again to become session leader + pid = fork(); + if(pid == -1) + error("pre-execution of command '%s' on pid %d: Cannot fork 2nd time.", command, getpid()); - // fork again to become session leader - pid = fork(); - if(pid == -1) fprintf(stderr, "Cannot fork again on pid %d\n", getpid()); - if(pid != 0) { - // the parent - exit(0); - } + if(pid != 0) { + // the parent + exit(0); + } - // set a new process group id for just this child - if( setpgid(0, 0) != 0 ) - fprintf(stderr, "Cannot set a new process group for pid %d (%s)\n", getpid(), strerror(errno)); + // set a new process group id for just this child + if( setpgid(0, 0) != 0 ) + error("pre-execution of command '%s' on pid %d: Cannot set a new process group.", command, getpid()); - if( getpgid(0) != getpid() ) - fprintf(stderr, "Process group set is incorrect. Expected %d, found %d\n", getpid(), getpgid(0)); + if( getpgid(0) != getpid() ) + error("pre-execution of command '%s' on pid %d: Cannot set a new process group. Process group set is incorrect. Expected %d, found %d", command, getpid(), getpid(), getpgid(0)); - if( setsid() != 0 ) - fprintf(stderr, "Cannot set session id for pid %d (%s)\n", getpid(), strerror(errno)); + if( setsid() != 0 ) + error("pre-execution of command '%s' on pid %d: Cannot set session id.", command, getpid()); - fprintf(stdout, "MYPID %d\n", getpid()); - fflush(NULL); + fprintf(stdout, "MYPID %d\n", getpid()); + fflush(NULL); #endif - - // ignore all signals - for (i = 1 ; i < 65 ;i++) if(i != SIGSEGV) signal(i, SIG_DFL); - fprintf(stderr, "executing command: '%s' on pid %d.\n", command, getpid()); - execl("/bin/sh", "sh", "-c", command, NULL); - exit(1); -} + // reset all signals + { + sigset_t sigset; + sigfillset(&sigset); -void mypclose(FILE *fp) -{ - // this is a very poor implementation of pclose() - // the caller should catch SIGCHLD and waitpid() on the exited child - // otherwise the child will be a zombie forever + if(pthread_sigmask(SIG_UNBLOCK, &sigset, NULL) == -1) + error("pre-execution of command '%s' on pid %d: could not unblock signals for threads.", command, getpid()); + + // We only need to reset ignored signals. + // Signals with signal handlers are reset by default. + struct sigaction sa; + sigemptyset(&sa.sa_mask); + sa.sa_handler = SIG_DFL; + sa.sa_flags = 0; + + if(sigaction(SIGINT, &sa, NULL) == -1) + error("pre-execution of command '%s' on pid %d: failed to set default signal handler for SIGINT.", command, getpid()); - fclose(fp); + if(sigaction(SIGTERM, &sa, NULL) == -1) + error("pre-execution of command '%s' on pid %d: failed to set default signal handler for SIGTERM.", command, getpid()); + + if(sigaction(SIGPIPE, &sa, NULL) == -1) + error("pre-execution of command '%s' on pid %d: failed to set default signal handler for SIGPIPE.", command, getpid()); + + if(sigaction(SIGHUP, &sa, NULL) == -1) + error("pre-execution of command '%s' on pid %d: failed to set default signal handler for SIGHUP.", command, getpid()); + + if(sigaction(SIGUSR1, &sa, NULL) == -1) + error("pre-execution of command '%s' on pid %d: failed to set default signal handler for SIGUSR1.", command, getpid()); + + if(sigaction(SIGUSR2, &sa, NULL) == -1) + error("pre-execution of command '%s' on pid %d: failed to set default signal handler for SIGUSR2.", command, getpid()); + } + + debug(D_CHILDS, "executing command: '%s' on pid %d.", command, getpid()); + execl("/bin/sh", "sh", "-c", command, NULL); + exit(1); } -void process_childs(int wait) -{ - siginfo_t info; - int options = WEXITED; - if(!wait) options |= WNOHANG; - - info.si_pid = 0; - while(waitid(P_ALL, 0, &info, options) == 0) { - if(!info.si_pid) break; - switch(info.si_code) { - case CLD_EXITED: - error("pid %d exited with code %d.", info.si_pid, info.si_status); - break; - - case CLD_KILLED: - error("pid %d killed by signal %d.", info.si_pid, info.si_status); - break; - - case CLD_DUMPED: - error("pid %d core dumped by signal %d.", info.si_pid, info.si_status); - break; - - case CLD_STOPPED: - error("pid %d stopped by signal %d.", info.si_pid, info.si_status); - break; - - case CLD_TRAPPED: - error("pid %d trapped by signal %d.", info.si_pid, info.si_status); - break; - - case CLD_CONTINUED: - error("pid %d continued by signal %d.", info.si_pid, info.si_status); - break; - - default: - error("pid %d gave us a SIGCHLD with code %d and status %d.", info.si_pid, info.si_code, info.si_status); - break; - } - - // prevent an infinite loop - info.si_pid = 0; - } +int mypclose(FILE *fp, pid_t pid) { + debug(D_EXIT, "Request to mypclose() on pid %d", pid); + + /*mypopen_del(fp);*/ + + // close the pipe fd + // this is required in musl + // without it the childs do not exit + close(fileno(fp)); + + // close the pipe file pointer + fclose(fp); + + siginfo_t info; + if(waitid(P_PID, (id_t) pid, &info, WEXITED) != -1) { + switch(info.si_code) { + case CLD_EXITED: + if(info.si_status) + error("child pid %d exited with code %d.", info.si_pid, info.si_status); + return(info.si_status); + break; + + case CLD_KILLED: + error("child pid %d killed by signal %d.", info.si_pid, info.si_status); + return(-1); + break; + + case CLD_DUMPED: + error("child pid %d core dumped by signal %d.", info.si_pid, info.si_status); + return(-2); + break; + + case CLD_STOPPED: + error("child pid %d stopped by signal %d.", info.si_pid, info.si_status); + return(0); + break; + + case CLD_TRAPPED: + error("child pid %d trapped by signal %d.", info.si_pid, info.si_status); + return(-4); + break; + + case CLD_CONTINUED: + error("child pid %d continued by signal %d.", info.si_pid, info.si_status); + return(0); + break; + + default: + error("child pid %d gave us a SIGCHLD with code %d and status %d.", info.si_pid, info.si_code, info.si_status); + return(-5); + break; + } + } + else + error("Cannot waitid() for pid %d", pid); + + return 0; }