linux(4): Refactor linux_common_recvmsg()

To improve readability lower nesting level, better naming for variables.
No functional changes.

MFC after:		2 weeks
This commit is contained in:
Dmitry Chagin 2022-05-28 23:46:22 +03:00
parent 71bc8bcf66
commit 0eda2ceab7

View File

@ -1691,9 +1691,9 @@ linux_recvmsg_common(struct thread *td, l_int s, struct l_msghdr *msghdr,
{
struct proc *p = td->td_proc;
struct cmsghdr *cm;
struct l_cmsghdr *linux_cmsg = NULL;
struct l_cmsghdr *lcm = NULL;
socklen_t datalen, maxlen, outlen;
struct l_msghdr linux_msghdr;
struct l_msghdr l_msghdr;
struct iovec *iov, *uiov;
struct mbuf *control = NULL;
struct mbuf **controlp;
@ -1702,7 +1702,7 @@ linux_recvmsg_common(struct thread *td, l_int s, struct l_msghdr *msghdr,
void *data, *udata;
int error;
error = copyin(msghdr, &linux_msghdr, sizeof(linux_msghdr));
error = copyin(msghdr, &l_msghdr, sizeof(l_msghdr));
if (error != 0)
return (error);
@ -1710,9 +1710,9 @@ linux_recvmsg_common(struct thread *td, l_int s, struct l_msghdr *msghdr,
* Pass user-supplied recvmsg() flags in msg_flags field,
* following sys_recvmsg() convention.
*/
linux_msghdr.msg_flags = flags;
l_msghdr.msg_flags = flags;
error = linux_to_bsd_msghdr(msg, &linux_msghdr);
error = linux_to_bsd_msghdr(msg, &l_msghdr);
if (error != 0)
return (error);
@ -1746,111 +1746,103 @@ linux_recvmsg_common(struct thread *td, l_int s, struct l_msghdr *msghdr,
* Note that kern_recvit() updates msg->msg_namelen.
*/
if (msg->msg_name != NULL && msg->msg_namelen > 0) {
msg->msg_name = PTRIN(linux_msghdr.msg_name);
msg->msg_name = PTRIN(l_msghdr.msg_name);
error = linux_copyout_sockaddr(sa, msg->msg_name,
msg->msg_namelen);
if (error != 0)
goto bad;
}
error = bsd_to_linux_msghdr(msg, &linux_msghdr);
error = bsd_to_linux_msghdr(msg, &l_msghdr);
if (error != 0)
goto bad;
maxlen = linux_msghdr.msg_controllen;
linux_msghdr.msg_controllen = 0;
if (control) {
linux_cmsg = malloc(L_CMSG_HDRSZ, M_LINUX, M_WAITOK | M_ZERO);
maxlen = l_msghdr.msg_controllen;
l_msghdr.msg_controllen = 0;
if (control == NULL)
goto out;
msg->msg_control = mtod(control, struct cmsghdr *);
msg->msg_controllen = control->m_len;
cm = CMSG_FIRSTHDR(msg);
outbuf = PTRIN(linux_msghdr.msg_control);
outlen = 0;
while (cm != NULL) {
linux_cmsg->cmsg_type =
bsd_to_linux_cmsg_type(p, cm->cmsg_type);
linux_cmsg->cmsg_level =
bsd_to_linux_sockopt_level(cm->cmsg_level);
if (linux_cmsg->cmsg_type == -1 ||
cm->cmsg_level != SOL_SOCKET) {
linux_msg(curthread,
"unsupported recvmsg cmsg level %d type %d",
cm->cmsg_level, cm->cmsg_type);
error = EINVAL;
goto bad;
}
data = CMSG_DATA(cm);
datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data;
udata = NULL;
switch (cm->cmsg_type) {
case SCM_RIGHTS:
error = recvmsg_scm_rights(td, flags,
&datalen, &data, &udata);
break;
case SCM_CREDS:
error = recvmsg_scm_creds(&datalen,
&data, &udata);
break;
case SCM_CREDS2:
error = recvmsg_scm_creds2(&datalen,
&data, &udata);
break;
case SCM_TIMESTAMP:
#if defined(__i386__) || (defined(__amd64__) && defined(COMPAT_LINUX32))
error = recvmsg_scm_timestamp(linux_cmsg->cmsg_type,
&datalen, &data, &udata);
#endif
break;
case SCM_BINTIME:
error = recvmsg_scm_timestampns(linux_cmsg->cmsg_type,
&datalen, &data, &udata);
break;
}
if (error != 0)
goto bad;
if (outlen + LINUX_CMSG_LEN(datalen) > maxlen) {
if (outlen == 0) {
error = EMSGSIZE;
goto err;
} else {
linux_msghdr.msg_flags |= LINUX_MSG_CTRUNC;
m_dispose_extcontrolm(control);
free(udata, M_LINUX);
goto out;
}
}
linux_cmsg->cmsg_len = LINUX_CMSG_LEN(datalen);
error = copyout(linux_cmsg, outbuf, L_CMSG_HDRSZ);
if (error == 0) {
outbuf += L_CMSG_HDRSZ;
error = copyout(data, outbuf, datalen);
if (error == 0) {
outbuf += LINUX_CMSG_ALIGN(datalen);
outlen += LINUX_CMSG_LEN(datalen);
cm = CMSG_NXTHDR(msg, cm);
}
}
err:
free(udata, M_LINUX);
if (error != 0)
goto bad;
lcm = malloc(L_CMSG_HDRSZ, M_LINUX, M_WAITOK | M_ZERO);
msg->msg_control = mtod(control, struct cmsghdr *);
msg->msg_controllen = control->m_len;
cm = CMSG_FIRSTHDR(msg);
outbuf = PTRIN(l_msghdr.msg_control);
outlen = 0;
while (cm != NULL) {
lcm->cmsg_type = bsd_to_linux_cmsg_type(p, cm->cmsg_type);
lcm->cmsg_level = bsd_to_linux_sockopt_level(cm->cmsg_level);
if (lcm->cmsg_type == -1 ||
cm->cmsg_level != SOL_SOCKET) {
linux_msg(curthread,
"unsupported recvmsg cmsg level %d type %d",
cm->cmsg_level, cm->cmsg_type);
error = EINVAL;
goto bad;
}
linux_msghdr.msg_controllen = outlen;
data = CMSG_DATA(cm);
datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data;
udata = NULL;
switch (cm->cmsg_type) {
case SCM_RIGHTS:
error = recvmsg_scm_rights(td, flags,
&datalen, &data, &udata);
break;
case SCM_CREDS:
error = recvmsg_scm_creds(&datalen,
&data, &udata);
break;
case SCM_CREDS2:
error = recvmsg_scm_creds2(&datalen,
&data, &udata);
break;
case SCM_TIMESTAMP:
#if defined(__i386__) || (defined(__amd64__) && defined(COMPAT_LINUX32))
error = recvmsg_scm_timestamp(lcm->cmsg_type,
&datalen, &data, &udata);
#endif
break;
case SCM_BINTIME:
error = recvmsg_scm_timestampns(lcm->cmsg_type,
&datalen, &data, &udata);
break;
}
if (error != 0)
goto bad;
if (outlen + LINUX_CMSG_LEN(datalen) > maxlen) {
if (outlen == 0) {
error = EMSGSIZE;
goto err;
} else {
l_msghdr.msg_flags |= LINUX_MSG_CTRUNC;
m_dispose_extcontrolm(control);
free(udata, M_LINUX);
goto out;
}
}
lcm->cmsg_len = LINUX_CMSG_LEN(datalen);
error = copyout(lcm, outbuf, L_CMSG_HDRSZ);
if (error == 0) {
outbuf += L_CMSG_HDRSZ;
error = copyout(data, outbuf, datalen);
if (error == 0) {
outbuf += LINUX_CMSG_ALIGN(datalen);
outlen += LINUX_CMSG_LEN(datalen);
cm = CMSG_NXTHDR(msg, cm);
}
}
err:
free(udata, M_LINUX);
if (error != 0)
goto bad;
}
l_msghdr.msg_controllen = outlen;
out:
error = copyout(&linux_msghdr, msghdr, sizeof(linux_msghdr));
error = copyout(&l_msghdr, msghdr, sizeof(l_msghdr));
bad:
if (control != NULL) {
@ -1859,7 +1851,7 @@ linux_recvmsg_common(struct thread *td, l_int s, struct l_msghdr *msghdr,
m_freem(control);
}
free(iov, M_IOV);
free(linux_cmsg, M_LINUX);
free(lcm, M_LINUX);
free(sa, M_SONAME);
return (error);