add some tools

1 files changed, 275 insertions, 0 deletions

diff --git a/tools/hi-q.c b/tools/hi-q.c
new file mode 100644
index 0000000..31ec77b
--- /dev/null
+++ b/tools/hi-q.c
@@ -0,0 +1,275 @@
+///////////////
+// lightweight connection from qmail to filters e.g. spamassassin
+// (hi-q filter, get it?)
+
+// TODO:  Panic stop should signal all children.
+// TODO:  Possibly:  Wait for all kids in parallel?
+//      That's because they might finish out of order.
+
+#include <unistd.h>
+#include <stdlib.h>             /* for malloc() */
+#include <stdio.h>
+#include <errno.h>
+#include <sys/types.h>          /* for fork(), wait() */
+#include <sys/stat.h>
+#include <sys/wait.h>
+
+using namespace std;
+#include <string>
+#include <vector>
+
+//  error exit codes, as stated in qmail.c
+const int ex_spam = 21;
+const int ex_syserr = 71;
+const int ex_comerr = 74;
+
+#define bufsize 16384
+
+void panic(const int sts) {
+  // FIXME: stop other children
+  exit(sts);
+}
+
+void slurp(const int inch, const int ouch){
+  char buf[bufsize];
+  ssize_t todo;
+  for (;;) {
+    ssize_t got = read(inch, buf, bufsize);
+    if (got == 0) {             // EoF
+      break;
+    }
+    if (got < 0) {
+      fprintf(stderr, "hi-q: input error: ");
+      perror(0);
+      panic(ex_comerr);
+    }
+
+    todo = got;
+    while (todo) {
+      ssize_t sent = write(ouch, buf, todo);
+      if (sent < 0 && errno != EINTR) {
+        fprintf(stderr, "hi-q: output error: ");
+        perror(0);
+        panic(ex_comerr);
+      }
+      todo -= sent;
+    }
+  }
+}
+
+
+void probe_fd(){
+  int ii;
+  struct stat buf;
+  for (ii = 0; ii < 16; ii++) {
+    int rslt = fstat(ii, &buf);
+    fprintf(stderr, "fd %2d status %2d", ii, rslt);
+    if (rslt==0)
+      fprintf(stderr, " : %d", (int)buf.st_dev);
+    fprintf(stderr, "\n");
+  }
+  fprintf(stderr, "============\n");
+}
+
+
+void blurb(const int ii, const pid_t* kidpid) {
+  int kidstatus;
+  /*pid_t somekid = */ waitpid(kidpid[ii], &kidstatus, WUNTRACED);
+  if (WIFEXITED(kidstatus))
+    fprintf(stderr, "kid #%d (%d) exited with status %d\n",
+              ii, kidpid[ii], WEXITSTATUS(kidstatus));
+  if (WIFSIGNALED(kidstatus))
+    fprintf(stderr, "kid #%d (%d) killed by signal %d\n",
+              ii, kidpid[ii], WTERMSIG(kidstatus));
+
+}
+
+// We are fussy about the argument types because we want
+// this to compile cleanly under g++ as well as gcc,
+// and each is strict about different things, such that
+// one or the other will complain unless everything is
+// done just right.
+
+// This is the way execve really behaves:
+// the characters are held constant
+// and the (char*) pointers are held constant:
+int Execve(char const * fn,
+           char const * const * argv,
+           char const * const * env) {
+// coerce the arg types to match the unwise declaration in unistd.h :
+  return execve(fn, (char*const*) argv, (char*const*) env);
+}
+
+////////////////////////////////////////
+// we have data coming in on fd 0.
+// and control coming in on fd 1.
+
+int main(int argc, char** argv, char const * const * env) {
+  int kidstatus;
+  pid_t somekid;
+
+  int rslt;
+  int loose_end = 0;
+
+#ifdef SpareStuff
+  char* slurp2_args[] = {"/home/jsd/hack/slurp2", 0};
+  char* echo_args[] = {"/bin/echo", "hi there", 0};
+  char* wc_args[] = {"/usr/bin/wc", 0};
+  char* cat_args[] = {"/bin/cat", 0};
+  char* spama_args[] = {"/usr/local/bin/spamassassin", "-e", 0};
+  char* spamc_args[] = {"/usr/local/bin/spamc", "-Z", "7", 0};
+  char* qq_args[] = {"/var/qmail/bin/qmail-queue", 0};
+
+  const char* spamc_args[] = {"/usr/local/bin/spamc", "-Z", "7", 0};
+  const char* qq_args[] = {"/var/qmail/bin/qmail-queue", 0};
+
+
+  const char** joblist[] = {
+    cat_args,
+    slurp2_args,
+    0           // required: zero terminates the list
+  };
+
+#endif
+
+  const char* spamc_args[] = {"/usr/local/bin/spamc", "-Z", "7", 0};
+  const char* qq_args[] = {"/var/qmail/bin/qmail-queue", 0};
+  const char** joblist[] = {
+    spamc_args,
+    qq_args,
+    0           // required: zero terminates the list
+  };
+
+  vector<vector<string> > filters;
+
+  int nkids;
+  pid_t* kidpid;        // indexed by kid number
+
+  for (nkids = 0; joblist[nkids]; nkids++) {}  // count 'em
+  kidpid = (pid_t*) malloc(nkids * sizeof(pid_t));
+
+// At this point, there is some loop invariants;
+// (a) fd0 is open and ready for the next child to read, and
+// (b) fd1 is open but is something children can (and should)
+//  throw away as soon as convenient.
+
+  {int ii; for (ii=0; joblist[ii]; ii++){  /* loop over all kids */
+    int datapipe[2];
+    int kid_end;
+    int lastkid = !joblist[ii+1];
+#define flip(a,b) (lastkid ? b : a)
+
+//xx fprintf(stderr, "Top of loop %d loose: %d\n", ii, loose_end);
+
+// Create a pipe, which will be used to connect
+// this child's fd1 to the next child's fd0 ...
+// except for the last kid, which reads fd1 rather
+// than writing it.
+    rslt = pipe(datapipe);
+    if (rslt < 0) {
+      fprintf(stderr, "hi-q: could not create datapipe: ");
+      perror(0);
+      panic(ex_syserr);
+    }
+
+//xx fprintf(stderr, "pipe: %d %d\n", datapipe[0], datapipe[1]);
+    if (loose_end) {
+      close(0);
+      dup2(loose_end, 0);
+      close(loose_end);
+    }
+
+    loose_end = datapipe[flip(0,1)];
+    kid_end = datapipe[flip(1,0)];
+
+    kidpid[ii] = fork();
+    if (!kidpid[ii]) {  /*** child code ***/
+      const char ** prog;
+
+// Now that we are through creating pipes, get rid
+// of the placeholder:
+      close(1);
+
+      close(loose_end);          // the reading end is none of our business
+
+      rslt = dup2(kid_end, 1);
+      if (rslt < 0) {
+        fprintf(stderr, "hi-q: dup2(kid(%d),1) failed: ", kid_end);
+        perror(0);
+        exit(ex_syserr);
+      }
+
+      close(kid_end);           // use fd1 instead now
+      // OK, at this point we are set up to read fd0
+      // and write fd1 (except last kid reads fd1).
+////  probe_fd();
+
+      prog = joblist[ii];
+      rslt = Execve(prog[0], prog, env);
+      fprintf(stderr, "hi-q: failed to exec '%s': ", prog[0]);
+      perror(0);
+      exit(ex_syserr);
+    }
+
+    /*** parent code ***/
+    if (kidpid[ii] < 0) {
+      fprintf(stderr, "hi-q: failure to fork kid#%d: ", ii);
+      perror(0);
+      panic(ex_syserr);
+    }
+    close(kid_end);
+#ifdef more_testing
+    fprintf(stderr, "forked kid #%d (%d) piping %d\n",
+                ii, kidpid[ii], kid_end);
+//    sleep(1); /* let kid run a while */
+#endif
+  }}
+
+// here with the whole pipeline of kids running
+
+  close(0);             // the reading end of stdin was
+                        // delegated to the first child
+
+
+  {int ii; for (ii=0; ii<nkids-1; ii++){        /* loop over N-1 kids */
+                                        /* not last kid */
+
+#ifdef testing
+    blurb(ii, kidpid);
+#else
+    somekid = waitpid(kidpid[ii], &kidstatus, WUNTRACED);
+    if (somekid) {}             // avoid silly compiler warning
+    if (WIFEXITED(kidstatus)) {
+      if (WEXITSTATUS(kidstatus) == 1) panic(ex_spam);
+      if (WEXITSTATUS(kidstatus) != 0) panic(ex_syserr);
+      /* otherwise kidstatus==0 and we fall through */
+    }
+    else panic(ex_syserr);      // any kill, not a normal exit
+#endif
+
+
+  }}
+
+//xx fprintf(stderr, "slurping %d %d\n", 1, loose_end);
+  slurp(1, loose_end);
+  close(1);
+  close(loose_end);
+
+  {
+    int ii = nkids-1;
+
+#ifdef moretesting
+fprintf(stderr, "About to wait for kid #%d (%d)\n",
+                ii, kidpid[ii]);
+    blurb(nkids-1, kidpid);
+#endif
+    somekid = waitpid(kidpid[ii], &kidstatus, WUNTRACED);
+    if (WIFEXITED(kidstatus)) return WEXITSTATUS(kidstatus);
+  }
+
+#ifdef testing
+  sleep(1);
+#endif
+  return ex_syserr;             // any kill, not a normal exit
+
+}