src/network/recvmsg.c

   1 #include <sys/socket.h>
   2 #include <limits.h>
   3 #include <time.h>
   4 #include <sys/time.h>
   5 #include <string.h>
   6 #include "syscall.h"
   7
   8 hidden void __convert_scm_timestamps(struct msghdr *, socklen_t);
   9
  10 void __convert_scm_timestamps(struct msghdr *msg, socklen_t csize)
  11 {
  12         if (SCM_TIMESTAMP == SCM_TIMESTAMP_OLD) return;
  13         if (!msg->msg_control || !msg->msg_controllen) return;
  14
  15         struct cmsghdr *cmsg, *last=0;
  16         long tmp;
  17         long long tvts[2];
  18         int type = 0;
  19
  20         for (cmsg=CMSG_FIRSTHDR(msg); cmsg; cmsg=CMSG_NXTHDR(msg, cmsg)) {
  21                 if (cmsg->cmsg_level==SOL_SOCKET) switch (cmsg->cmsg_type) {
  22                 case SCM_TIMESTAMP_OLD:
  23                         if (type) break;
  24                         type = SCM_TIMESTAMP;
  25                         goto common;
  26                 case SCM_TIMESTAMPNS_OLD:
  27                         type = SCM_TIMESTAMPNS;
  28                 common:
  29                         memcpy(&tmp, CMSG_DATA(cmsg), sizeof tmp);
  30                         tvts[0] = tmp;
  31                         memcpy(&tmp, CMSG_DATA(cmsg) + sizeof tmp, sizeof tmp);
  32                         tvts[1] = tmp;
  33                         break;
  34                 }
  35                 last = cmsg;
  36         }
  37         if (!last || !type) return;
  38         if (CMSG_SPACE(sizeof tvts) > csize-msg->msg_controllen) {
  39                 msg->msg_flags |= MSG_CTRUNC;
  40                 return;
  41         }
  42         msg->msg_controllen += CMSG_SPACE(sizeof tvts);
  43         cmsg = CMSG_NXTHDR(msg, last);
  44         cmsg->cmsg_level = SOL_SOCKET;
  45         cmsg->cmsg_type = type;
  46         cmsg->cmsg_len = CMSG_LEN(sizeof tvts);
  47         memcpy(CMSG_DATA(cmsg), &tvts, sizeof tvts);
  48 }
  49
  50 ssize_t recvmsg(int fd, struct msghdr *msg, int flags)
  51 {
  52         ssize_t r;
  53         socklen_t orig_controllen = msg->msg_controllen;
  54 #if LONG_MAX > INT_MAX
  55         struct msghdr h, *orig = msg;
  56         if (msg) {
  57                 h = *msg;
  58                 h.__pad1 = h.__pad2 = 0;
  59                 msg = &h;
  60         }
  61 #endif
  62         r = socketcall_cp(recvmsg, fd, msg, flags, 0, 0, 0);
  63         if (r >= 0) __convert_scm_timestamps(msg, orig_controllen);
  64 #if LONG_MAX > INT_MAX
  65         if (orig) *orig = h;
  66 #endif
  67         return r;
  68 }