util.c

   1 #include <errno.h>
   2 #include <fcntl.h>
   3 #include <poll.h>
   4 #include <unistd.h>
   5 #include <stdlib.h>
   6 #include <string.h>
   7 #include <sys/types.h>
   8 #include <sys/wait.h>
   9 #include "mail.h"
  10
  11 long xread(int fd, void *buf, long len)
  12 {
  13         int nr = 0;
  14         while (nr < len) {
  15                 int ret = read(fd, buf + nr, len - nr);
  16                 if (ret == -1 && (errno == EAGAIN || errno == EINTR))
  17                         continue;
  18                 if (ret <= 0)
  19                         break;
  20                 nr += ret;
  21         }
  22         return nr;
  23 }
  24
  25 long xwrite(int fd, void *buf, long len)
  26 {
  27         int nw = 0;
  28         while (nw < len) {
  29                 int ret = write(fd, buf + nw, len - nw);
  30                 if (ret == -1 && (errno == EAGAIN || errno == EINTR))
  31                         continue;
  32                 if (ret < 0)
  33                         break;
  34                 nw += ret;
  35         }
  36         return nw;
  37 }
  38
  39 static int xpipe_make(char **argv, int *ifd, int *ofd)
  40 {
  41         int pid;
  42         int pipefds0[2];
  43         int pipefds1[2];
  44         if (ifd)
  45                 pipe(pipefds0);
  46         if (ofd)
  47                 pipe(pipefds1);
  48         if (!(pid = fork())) {
  49                 if (ifd) {              /* setting up stdin */
  50                         close(0);
  51                         dup(pipefds0[0]);
  52                         close(pipefds0[1]);
  53                         close(pipefds0[0]);
  54                 }
  55                 if (ofd) {              /* setting up stdout */
  56                         close(1);
  57                         dup(pipefds1[1]);
  58                         close(pipefds1[0]);
  59                         close(pipefds1[1]);
  60                 }
  61                 execvp(argv[0], argv);
  62                 exit(1);
  63         }
  64         if (ifd)
  65                 close(pipefds0[0]);
  66         if (ofd)
  67                 close(pipefds1[1]);
  68         if (pid < 0) {
  69                 if (ifd)
  70                         close(pipefds0[1]);
  71                 if (ofd)
  72                         close(pipefds1[0]);
  73                 return -1;
  74         }
  75         if (ifd)
  76                 *ifd = pipefds0[1];
  77         if (ofd)
  78                 *ofd = pipefds1[0];
  79         return pid;
  80 }
  81
  82 int xpipe(char *cmd, char *ibuf, long ilen, char **obuf, long *olen)
  83 {
  84         char *argv[] = {"/bin/sh", "-c", cmd, NULL};
  85         struct pollfd fds[2];
  86         struct sbuf *sb = NULL;
  87         char buf[512];
  88         int ifd = -1, ofd = -1;
  89         int nw = 0;
  90         int pid = xpipe_make(argv, ibuf ? &ifd : NULL, obuf ? &ofd : NULL);
  91         if (pid <= 0)
  92                 return 1;
  93         if (obuf)
  94                 sb = sbuf_make();
  95         fcntl(ifd, F_SETFL, fcntl(ifd, F_GETFL, 0) | O_NONBLOCK);
  96         fds[0].fd = ofd;
  97         fds[0].events = POLLIN;
  98         fds[1].fd = ifd;
  99         fds[1].events = POLLOUT;
 100         while ((fds[0].fd >= 0 || fds[1].fd >= 0) && poll(fds, 2, 200) >= 0) {
 101                 if (fds[0].revents & POLLIN) {
 102                         int ret = read(fds[0].fd, buf, sizeof(buf));
 103                         if (ret > 0)
 104                                 sbuf_mem(sb, buf, ret);
 105                         if (ret <= 0) {
 106                                 close(fds[0].fd);
 107                                 fds[0].fd = -1;
 108                         }
 109                 } else if (fds[0].revents & (POLLERR | POLLHUP | POLLNVAL)) {
 110                         fds[0].fd = -1;
 111                 }
 112                 if (fds[1].revents & POLLOUT) {
 113                         int ret = write(fds[1].fd, ibuf + nw, ilen - nw);
 114                         if (ret > 0)
 115                                 nw += ret;
 116                         if (ret <= 0 || nw == ilen) {
 117                                 close(fds[1].fd);
 118                                 fds[1].fd = -1;
 119                         }
 120                 } else if (fds[1].revents & (POLLERR | POLLHUP | POLLNVAL)) {
 121                         fds[1].fd = -1;
 122                 }
 123         }
 124         close(ifd);
 125         close(ofd);
 126         waitpid(pid, NULL, 0);
 127         if (obuf) {
 128                 *olen = sbuf_len(sb);
 129                 *obuf = sbuf_done(sb);
 130         }
 131         return 0;
 132 }