| Message ID | 20100422092826.EF03612B5C@gandalf.tls.msk.ru |
|---|---|
| State | New |
| Headers | show |
Michael Tokarev <mjt@tls.msk.ru> writes: > In net/tap-linux.c, when manipulation of /dev/net/tun fails, it prints > (with fprintf) something like this: > > warning: could not open /dev/net/tun: no virtual network emulation > > this has 2 issues: > 1) it is not a warning really, it's a fatal error (kvm exits after that), > 2) there's no indication as of what's actually wrong: printing errno there > is helpful. > > The patch below removes the "warning" prefix, uses %m (since it's linux, > %m is available as format modifier), and changes fprintf() to qemu_error(). > Now it prints something like this instead: > > could not configure /dev/net/tun: Device or resource busy > > (there are 2 messages like that in the same function) > > This fixes Debian bug #578154, see > http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=578154 > > Signed-Off-By: Michael Tokarev <mjt@tls.msk.ru> > > diff --git a/net/tap-linux.c b/net/tap-linux.c > index 6af9e82..dbcbe6f 100644 > --- a/net/tap-linux.c > +++ b/net/tap-linux.c > @@ -39,7 +39,7 @@ int tap_open(char *ifname, int ifname_size, int *vnet_hdr, int vnet_hdr_required > > TFR(fd = open("/dev/net/tun", O_RDWR)); > if (fd < 0) { > - fprintf(stderr, "warning: could not open /dev/net/tun: no virtual network emulation\n"); > + qemu_error("could not open /dev/net/tun: %m\n"); > return -1; > } > memset(&ifr, 0, sizeof(ifr)); This might apply to the stable branch (I haven't tried), but I don't think it works on master. There, it should look like this (untested): + error_report("could not open /dev/net/tun: %m"); [...]
Am 22.04.2010 11:52, schrieb Markus Armbruster: > Michael Tokarev <mjt@tls.msk.ru> writes: > >> In net/tap-linux.c, when manipulation of /dev/net/tun fails, it prints >> (with fprintf) something like this: >> >> warning: could not open /dev/net/tun: no virtual network emulation >> >> this has 2 issues: >> 1) it is not a warning really, it's a fatal error (kvm exits after that), >> 2) there's no indication as of what's actually wrong: printing errno there >> is helpful. >> >> The patch below removes the "warning" prefix, uses %m (since it's linux, >> %m is available as format modifier), and changes fprintf() to qemu_error(). >> Now it prints something like this instead: >> >> could not configure /dev/net/tun: Device or resource busy >> >> (there are 2 messages like that in the same function) >> >> This fixes Debian bug #578154, see >> http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=578154 >> >> Signed-Off-By: Michael Tokarev <mjt@tls.msk.ru> >> >> diff --git a/net/tap-linux.c b/net/tap-linux.c >> index 6af9e82..dbcbe6f 100644 >> --- a/net/tap-linux.c >> +++ b/net/tap-linux.c >> @@ -39,7 +39,7 @@ int tap_open(char *ifname, int ifname_size, int *vnet_hdr, int vnet_hdr_required >> >> TFR(fd = open("/dev/net/tun", O_RDWR)); >> if (fd < 0) { >> - fprintf(stderr, "warning: could not open /dev/net/tun: no virtual network emulation\n"); >> + qemu_error("could not open /dev/net/tun: %m\n"); >> return -1; >> } >> memset(&ifr, 0, sizeof(ifr)); > > This might apply to the stable branch (I haven't tried), but I don't > think it works on master. There, it should look like this (untested): > > + error_report("could not open /dev/net/tun: %m"); I'm not sure where this %m is defined exactly (Linux specific? Maybe BSDs, too?), but it doesn't seem to work with mingw. Kevin
Kevin Wolf wrote: > Am 22.04.2010 11:52, schrieb Markus Armbruster: >> Michael Tokarev <mjt@tls.msk.ru> writes: >> >>> In net/tap-linux.c, when manipulation of /dev/net/tun fails, it prints >>> (with fprintf) something like this: >>> [] >>> TFR(fd = open("/dev/net/tun", O_RDWR)); >>> if (fd < 0) { >>> - fprintf(stderr, "warning: could not open /dev/net/tun: no virtual network emulation\n"); >>> + qemu_error("could not open /dev/net/tun: %m\n"); >>> return -1; > > I'm not sure where this %m is defined exactly (Linux specific? Maybe > BSDs, too?), but it doesn't seem to work with mingw. The file being patched is tap-linux.c. I noted this in my first email. Thanks! /mjt
Am 23.04.2010 14:52, schrieb Michael Tokarev: > Kevin Wolf wrote: >> Am 22.04.2010 11:52, schrieb Markus Armbruster: >>> Michael Tokarev <mjt@tls.msk.ru> writes: >>> >>>> In net/tap-linux.c, when manipulation of /dev/net/tun fails, it prints >>>> (with fprintf) something like this: >>>> > [] >>>> TFR(fd = open("/dev/net/tun", O_RDWR)); >>>> if (fd < 0) { >>>> - fprintf(stderr, "warning: could not open /dev/net/tun: no virtual network emulation\n"); >>>> + qemu_error("could not open /dev/net/tun: %m\n"); >>>> return -1; >> >> I'm not sure where this %m is defined exactly (Linux specific? Maybe >> BSDs, too?), but it doesn't seem to work with mingw. > > The file being patched is tap-linux.c. > I noted this in my first email. Sorry, I missed that. You're right, of course. Kevin
On 04/23/2010 08:28 AM, Kevin Wolf wrote: > Am 23.04.2010 14:52, schrieb Michael Tokarev: > >> Kevin Wolf wrote: >> >>> Am 22.04.2010 11:52, schrieb Markus Armbruster: >>> >>>> Michael Tokarev<mjt@tls.msk.ru> writes: >>>> >>>> >>>>> In net/tap-linux.c, when manipulation of /dev/net/tun fails, it prints >>>>> (with fprintf) something like this: >>>>> >>>>> >> [] >> >>>>> TFR(fd = open("/dev/net/tun", O_RDWR)); >>>>> if (fd< 0) { >>>>> - fprintf(stderr, "warning: could not open /dev/net/tun: no virtual network emulation\n"); >>>>> + qemu_error("could not open /dev/net/tun: %m\n"); >>>>> return -1; >>>>> >>> I'm not sure where this %m is defined exactly (Linux specific? Maybe >>> BSDs, too?), but it doesn't seem to work with mingw. >>> >> The file being patched is tap-linux.c. >> I noted this in my first email. >> > Sorry, I missed that. You're right, of course. > But from a consistency perspective, "%s", strerror(errno) would be nicer even if it's technically okay. Regards, Anthony Liguori > Kevin > > > >
diff --git a/net/tap-linux.c b/net/tap-linux.c index 6af9e82..dbcbe6f 100644 --- a/net/tap-linux.c +++ b/net/tap-linux.c @@ -39,7 +39,7 @@ int tap_open(char *ifname, int ifname_size, int *vnet_hdr, int vnet_hdr_required TFR(fd = open("/dev/net/tun", O_RDWR)); if (fd < 0) { - fprintf(stderr, "warning: could not open /dev/net/tun: no virtual network emulation\n"); + qemu_error("could not open /dev/net/tun: %m\n"); return -1; } memset(&ifr, 0, sizeof(ifr)); @@ -70,7 +70,7 @@ int tap_open(char *ifname, int ifname_size, int *vnet_hdr, int vnet_hdr_required pstrcpy(ifr.ifr_name, IFNAMSIZ, "tap%d"); ret = ioctl(fd, TUNSETIFF, (void *) &ifr); if (ret != 0) { - fprintf(stderr, "warning: could not configure /dev/net/tun: no virtual network emulation\n"); + qemu_error("could not configure /dev/net/tun: %m\n"); close(fd); return -1; }
In net/tap-linux.c, when manipulation of /dev/net/tun fails, it prints (with fprintf) something like this: warning: could not open /dev/net/tun: no virtual network emulation this has 2 issues: 1) it is not a warning really, it's a fatal error (kvm exits after that), 2) there's no indication as of what's actually wrong: printing errno there is helpful. The patch below removes the "warning" prefix, uses %m (since it's linux, %m is available as format modifier), and changes fprintf() to qemu_error(). Now it prints something like this instead: could not configure /dev/net/tun: Device or resource busy (there are 2 messages like that in the same function) This fixes Debian bug #578154, see http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=578154 Signed-Off-By: Michael Tokarev <mjt@tls.msk.ru>