* [PATCH 0/2] agetty: display network address in issue [not found] <2B6CF89C-6218-4289-B116-27108562664F@endian.com> @ 2012-08-15 9:08 ` Andrea Bonomi 2012-09-12 9:37 ` Karel Zak 0 siblings, 1 reply; 4+ messages in thread From: Andrea Bonomi @ 2012-08-15 9:08 UTC (permalink / raw) To: util-linux Hello, I developed a small patch for displaying the network address (IPv4 or IPv6) of a selected network interface in the agetty issue file. The name of network interface (default eth0) can be configured through a command line option. I use this feature on my virtual machines, so I can know the addresses without login. I hope this can be useful for someone else. Have a nice day, Andrea Bonomi :: e n d i a n :: security with passion :: andrea bonomi :: senior software engineer :: http://www.endian.com :: a.bonomi@endian.com ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH 0/2] agetty: display network address in issue 2012-08-15 9:08 ` [PATCH 0/2] agetty: display network address in issue Andrea Bonomi @ 2012-09-12 9:37 ` Karel Zak 2012-09-12 17:29 ` Andrea Bonomi 0 siblings, 1 reply; 4+ messages in thread From: Karel Zak @ 2012-09-12 9:37 UTC (permalink / raw) To: Andrea Bonomi; +Cc: util-linux Hi, On Wed, Aug 15, 2012 at 11:08:16AM +0200, Andrea Bonomi wrote: > Hello, I developed a small patch for displaying the network address > (IPv4 or IPv6) of a selected network interface in the agetty issue > file. The name of network interface (default eth0) can be > configured through a command line option. I use this feature on my > virtual machines, so I can know the addresses without login. I hope > this can be useful for someone else. Have a nice day, Andrea Bonomi I did some changes to the patch -- see below. I don't like the hardcoded interface names and I guess that on many machines is more important just machine IP (based on hostname) rather than interface IP. So: \4 and \6 print IP address as returned by getaddrinfo() *or* if --interface command line option is specified then interface IP is printed. It means that --interface is optional and probably unnecessary in many cases. Objections? Karel >From ca2fda5f40440f4f7686716d76f93c302f1b2e67 Mon Sep 17 00:00:00 2001 From: Andrea Bonomi <a.bonomi@endian.com> Date: Wed, 15 Aug 2012 11:10:19 +0200 Subject: [PATCH] agetty: display network address in issue Signed-off-by: Andrea Bonomi <a.bonomi@endian.com> Signed-off-by: Karel Zak <kzak@redhat.com> --- term-utils/agetty.8 | 18 +++++++++- term-utils/agetty.c | 96 +++++++++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 111 insertions(+), 3 deletions(-) diff --git a/term-utils/agetty.8 b/term-utils/agetty.8 index ebfdb96..bbf65d0 100644 --- a/term-utils/agetty.8 +++ b/term-utils/agetty.8 @@ -3,7 +3,7 @@ agetty \- alternative Linux getty .SH SYNOPSIS -.BR "agetty " [\-8chiLmnsUw] +.BR "agetty " [\-8chiLmnsUwx] .RI "[\-a " user ] .RI "[\-f " issue_file ] .RI "[\-H " login_host ] @@ -198,6 +198,10 @@ Wait for the user or the modem to send a carriage-return or a linefeed character before sending the \fI/etc/issue\fP (or other) file and the login prompt. Very useful in connection with the \-I option. .TP +\-x, \-\-interface \fIinterface_name\fP +The IPv4 and IPv6 addresses of a network interface can be displayed in +the issue. The name of the network is configured by this option. +.TP \-\-noclear Do not clear the screen before prompting for the login name (the screen is normally cleared). @@ -269,6 +273,18 @@ time etc. All escape codes consist of a backslash (\\) immediately followed by one of the letters explained below. .TP +4 +Insert the IPv4 address of the machine hostname or IPv4 address the configured +network interface if the \fB\-\-interface\fP command line option is specified. +.TP +6 +Insert the IPv6 address of the machine hostname or IPv6 address the configured +network interface if the \fB\-\-interface\fP command line option is specified. +.TP +x +Name of the configured network interface (configured by the \fB\-\-interface\fP +command line option). +.TP b Insert the baudrate of the current line. .TP diff --git a/term-utils/agetty.c b/term-utils/agetty.c index 43243f9..71c7da3 100644 --- a/term-utils/agetty.c +++ b/term-utils/agetty.c @@ -31,6 +31,9 @@ #include <netdb.h> #include <langinfo.h> #include <grp.h> +#include <arpa/inet.h> +#include <netdb.h> +#include <ifaddrs.h> #include "strutils.h" #include "all-io.h" @@ -145,6 +148,7 @@ struct options { int nice; /* Run login with this priority */ int numspeed; /* number of baud rates to try */ speed_t speeds[MAX_SPEED]; /* baud rates to be tried */ + char *interface; /* name of the network interface displayed in issue */ }; #define F_PARSE (1<<0) /* process modem status messages */ @@ -169,6 +173,7 @@ struct options { #define F_LONGHNAME (1<<19) /* Show Full qualified hostname */ #define F_NOHINTS (1<<20) /* Don't print hints */ #define F_REMOTE (1<<21) /* Add '-h fakehost' to login(1) command line */ +#define F_INTERFACE (1<<22) /* Name of the network interface displayed in issue */ #define serial_tty_option(opt, flag) \ (((opt)->flags & (F_VCONSOLE|(flag))) == (flag)) @@ -280,7 +285,7 @@ int main(int argc, char **argv) .login = _PATH_LOGIN, /* default login program */ .tty = "tty1", /* default tty line */ .term = DEFAULT_VCTERM, /* terminal type */ - .issue = ISSUE /* default issue file */ + .issue = ISSUE, /* default issue file */ }; char *login_argv[LOGIN_ARGV_MAX + 1]; int login_argc = 0; @@ -569,6 +574,7 @@ static void parse_args(int argc, char **argv, struct options *op) { "timeout", required_argument, 0, 't' }, { "detect-case", no_argument, 0, 'U' }, { "wait-cr", no_argument, 0, 'w' }, + { "interface", required_argument, 0, 'x' }, { "nohints", no_argument, 0, NOHINTS_OPTION }, { "nohostname", no_argument, 0, NOHOSTNAME_OPTION }, { "long-hostname", no_argument, 0, LONGHOSTNAME_OPTION }, @@ -578,7 +584,7 @@ static void parse_args(int argc, char **argv, struct options *op) }; while ((c = getopt_long(argc, argv, - "8a:cC:d:Ef:hH:iI:Jl:LmnNo:pP:r:Rst:Uw", longopts, + "8a:cC:d:Ef:hH:iI:Jl:LmnNo:pP:r:Rst:Uwx:", longopts, NULL)) != -1) { switch (c) { case '8': @@ -659,6 +665,10 @@ static void parse_args(int argc, char **argv, struct options *op) case 'w': op->flags |= F_WAITCRLF; break; + case 'x': + op->flags |= F_INTERFACE; + op->interface = optarg; + break; case NOHINTS_OPTION: op->flags |= F_NOHINTS; break; @@ -1696,6 +1706,68 @@ static void log_warn(const char *fmt, ...) va_end(ap); } +static void output_iface_ip(struct ifaddrs *addrs, const char *iface, sa_family_t family) +{ + if (!iface) + return; + + if (addrs->ifa_name + && strcmp(addrs->ifa_name, iface) == 0 + && addrs->ifa_addr + && addrs->ifa_addr->sa_family == family) { + + void *addr = NULL; + char buff[INET6_ADDRSTRLEN + 1]; + + switch (addrs->ifa_addr->sa_family) { + case AF_INET: + addr = &((struct sockaddr_in *) addrs->ifa_addr)->sin_addr; + break; + case AF_INET6: + addr = &((struct sockaddr_in6 *) addrs->ifa_addr)->sin6_addr; + break; + } + if (addr) { + inet_ntop(addrs->ifa_addr->sa_family, addr, buff, sizeof(buff)); + printf("%s", buff); + } + + } else if (addrs->ifa_next) + output_iface_ip(addrs->ifa_next, iface, family); +} + +static void output_ip(sa_family_t family) +{ + char host[MAXHOSTNAMELEN + 1]; + struct addrinfo hints, *info = NULL; + + memset(&hints, 0, sizeof(hints)); + hints.ai_family = family; + if (family == AF_INET6) + hints.ai_flags = AI_V4MAPPED; + + if (gethostname(host, sizeof(host)) == 0 + && getaddrinfo(host, NULL, &hints, &info) == 0 + && info) { + + void *addr = NULL; + char buff[INET6_ADDRSTRLEN + 1]; + + switch (info->ai_family) { + case AF_INET: + addr = &((struct sockaddr_in *) info->ai_addr)->sin_addr; + break; + case AF_INET6: + addr = &((struct sockaddr_in6 *) info->ai_addr)->sin6_addr; + break; + } + inet_ntop(info->ai_family, (void *) addr, buff, sizeof(buff)); + printf("%s", buff); + + freeaddrinfo(info); + } +} + static void output_special_char(unsigned char c, struct options *op, struct termios *tp) { @@ -1808,6 +1880,26 @@ static void output_special_char(unsigned char c, struct options *op, printf((users == 1) ? _("user") : _("users")); break; } + case 'x': + if (op->interface) /* interface name */ + printf("%s", op->interface); + break; + case '4': + case '6': + { + sa_family_t family = c == '4' ? AF_INET : AF_INET6; + + if (op->interface) { /* interface IP */ + struct ifaddrs *addrs; + int status = getifaddrs(&addrs); + if (status != 0) + break; + output_iface_ip(addrs, op->interface, family); + freeifaddrs(addrs); + } else /* host IP */ + output_ip(family); + break; + } default: putchar(c); break; -- 1.7.7.6 ^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH 0/2] agetty: display network address in issue 2012-09-12 9:37 ` Karel Zak @ 2012-09-12 17:29 ` Andrea Bonomi 2012-09-13 11:05 ` Karel Zak 0 siblings, 1 reply; 4+ messages in thread From: Andrea Bonomi @ 2012-09-12 17:29 UTC (permalink / raw) To: Karel Zak; +Cc: util-linux Hi, good idea, much better without the hardcoded interface name. I think that the --interface option is useful for the machine with a = dynamic IP address. (in my experience, the getaddrinfo based on the hostname returns the = loopback address) Another idea will be to add the interface name after the \4 or \6, = something like: \4eth0 (or similar=85) to get the IPv4 address of the interface eth0 So the user can specify the interface name directly in the issue file. What do you think? Andrea :: e n d i a n :: security with passion :: andrea bonomi :: senior software engineer :: http://www.endian.com :: a.bonomi@endian.com On 12/set/2012, at 11:37, Karel Zak wrote: >=20 > Hi, >=20 > On Wed, Aug 15, 2012 at 11:08:16AM +0200, Andrea Bonomi wrote: >> Hello, I developed a small patch for displaying the network address >> (IPv4 or IPv6) of a selected network interface in the agetty issue >> file. The name of network interface (default eth0) can be >> configured through a command line option. I use this feature on my >> virtual machines, so I can know the addresses without login. I hope >> this can be useful for someone else. Have a nice day, Andrea Bonomi >=20 > I did some changes to the patch -- see below. I don't like the > hardcoded interface names and I guess that on many machines is more > important just machine IP (based on hostname) rather than interface > IP. So: >=20 > \4 and \6 print IP address as returned by getaddrinfo() *or* if > --interface command line option is specified then interface IP is > printed. >=20 > It means that --interface is optional and probably unnecessary in many > cases. >=20 > Objections? >=20 > Karel >=20 > =46rom ca2fda5f40440f4f7686716d76f93c302f1b2e67 Mon Sep 17 00:00:00 = 2001 > From: Andrea Bonomi <a.bonomi@endian.com> > Date: Wed, 15 Aug 2012 11:10:19 +0200 > Subject: [PATCH] agetty: display network address in issue >=20 > Signed-off-by: Andrea Bonomi <a.bonomi@endian.com> > Signed-off-by: Karel Zak <kzak@redhat.com> > --- > term-utils/agetty.8 | 18 +++++++++- > term-utils/agetty.c | 96 = +++++++++++++++++++++++++++++++++++++++++++++++++- > 2 files changed, 111 insertions(+), 3 deletions(-) >=20 > diff --git a/term-utils/agetty.8 b/term-utils/agetty.8 > index ebfdb96..bbf65d0 100644 > --- a/term-utils/agetty.8 > +++ b/term-utils/agetty.8 > @@ -3,7 +3,7 @@ > agetty \- alternative Linux getty >=20 > .SH SYNOPSIS > -.BR "agetty " [\-8chiLmnsUw] > +.BR "agetty " [\-8chiLmnsUwx] > .RI "[\-a " user ] > .RI "[\-f " issue_file ] > .RI "[\-H " login_host ] > @@ -198,6 +198,10 @@ Wait for the user or the modem to send a = carriage-return or a > linefeed character before sending the \fI/etc/issue\fP (or other) file > and the login prompt. Very useful in connection with the \-I option. > .TP > +\-x, \-\-interface \fIinterface_name\fP > +The IPv4 and IPv6 addresses of a network interface can be displayed = in > +the issue. The name of the network is configured by this option. > +.TP > \-\-noclear > Do not clear the screen before prompting for the login name > (the screen is normally cleared). > @@ -269,6 +273,18 @@ time etc. All escape codes consist of a backslash = (\\) immediately > followed by one of the letters explained below. >=20 > .TP > +4 > +Insert the IPv4 address of the machine hostname or IPv4 address the = configured > +network interface if the \fB\-\-interface\fP command line option is = specified. > +.TP > +6 > +Insert the IPv6 address of the machine hostname or IPv6 address the = configured > +network interface if the \fB\-\-interface\fP command line option is = specified. > +.TP > +x > +Name of the configured network interface (configured by the = \fB\-\-interface\fP > +command line option). > +.TP > b > Insert the baudrate of the current line. > .TP > diff --git a/term-utils/agetty.c b/term-utils/agetty.c > index 43243f9..71c7da3 100644 > --- a/term-utils/agetty.c > +++ b/term-utils/agetty.c > @@ -31,6 +31,9 @@ > #include <netdb.h> > #include <langinfo.h> > #include <grp.h> > +#include <arpa/inet.h> > +#include <netdb.h> > +#include <ifaddrs.h> >=20 > #include "strutils.h" > #include "all-io.h" > @@ -145,6 +148,7 @@ struct options { > int nice; /* Run login with this priority = */ > int numspeed; /* number of baud rates to try = */ > speed_t speeds[MAX_SPEED]; /* baud rates to be tried */ > + char *interface; /* name of the network interface = displayed in issue */ > }; >=20 > #define F_PARSE (1<<0) /* process modem status messages = */ > @@ -169,6 +173,7 @@ struct options { > #define F_LONGHNAME (1<<19) /* Show Full qualified hostname */ > #define F_NOHINTS (1<<20) /* Don't print hints */ > #define F_REMOTE (1<<21) /* Add '-h fakehost' to login(1) command = line */ > +#define F_INTERFACE (1<<22) /* Name of the network interface = displayed in issue */ >=20 > #define serial_tty_option(opt, flag) \ > (((opt)->flags & (F_VCONSOLE|(flag))) =3D=3D (flag)) > @@ -280,7 +285,7 @@ int main(int argc, char **argv) > .login =3D _PATH_LOGIN, /* default login = program */ > .tty =3D "tty1", /* default tty line */ > .term =3D DEFAULT_VCTERM, /* terminal type */ > - .issue =3D ISSUE /* default issue file */ > + .issue =3D ISSUE, /* default issue file */ > }; > char *login_argv[LOGIN_ARGV_MAX + 1]; > int login_argc =3D 0; > @@ -569,6 +574,7 @@ static void parse_args(int argc, char **argv, = struct options *op) > { "timeout", required_argument, 0, 't' }, > { "detect-case", no_argument, 0, 'U' }, > { "wait-cr", no_argument, 0, 'w' }, > + { "interface", required_argument, 0, 'x' }, > { "nohints", no_argument, 0, = NOHINTS_OPTION }, > { "nohostname", no_argument, 0, = NOHOSTNAME_OPTION }, > { "long-hostname", no_argument, 0, = LONGHOSTNAME_OPTION }, > @@ -578,7 +584,7 @@ static void parse_args(int argc, char **argv, = struct options *op) > }; >=20 > while ((c =3D getopt_long(argc, argv, > - "8a:cC:d:Ef:hH:iI:Jl:LmnNo:pP:r:Rst:Uw", = longopts, > + "8a:cC:d:Ef:hH:iI:Jl:LmnNo:pP:r:Rst:Uwx:", = longopts, > NULL)) !=3D -1) { > switch (c) { > case '8': > @@ -659,6 +665,10 @@ static void parse_args(int argc, char **argv, = struct options *op) > case 'w': > op->flags |=3D F_WAITCRLF; > break; > + case 'x': > + op->flags |=3D F_INTERFACE; > + op->interface =3D optarg; > + break; > case NOHINTS_OPTION: > op->flags |=3D F_NOHINTS; > break; > @@ -1696,6 +1706,68 @@ static void log_warn(const char *fmt, ...) > va_end(ap); > } >=20 > +static void output_iface_ip(struct ifaddrs *addrs, const char *iface, = sa_family_t family) > +{ > + if (!iface) > + return; > + > + if (addrs->ifa_name > + && strcmp(addrs->ifa_name, iface) =3D=3D 0 > + && addrs->ifa_addr > + && addrs->ifa_addr->sa_family =3D=3D family) { > + > + void *addr =3D NULL; > + char buff[INET6_ADDRSTRLEN + 1]; > + > + switch (addrs->ifa_addr->sa_family) { > + case AF_INET: > + addr =3D &((struct sockaddr_in *) = addrs->ifa_addr)->sin_addr; > + break; > + case AF_INET6: > + addr =3D &((struct sockaddr_in6 *) = addrs->ifa_addr)->sin6_addr; > + break; > + } > + if (addr) { > + inet_ntop(addrs->ifa_addr->sa_family, addr, = buff, sizeof(buff)); > + printf("%s", buff); > + } > + > + } else if (addrs->ifa_next) > + output_iface_ip(addrs->ifa_next, iface, family); > +} > + > +static void output_ip(sa_family_t family) > +{ > + char host[MAXHOSTNAMELEN + 1]; > + struct addrinfo hints, *info =3D NULL; > + > + memset(&hints, 0, sizeof(hints)); > + hints.ai_family =3D family; > + if (family =3D=3D AF_INET6) > + hints.ai_flags =3D AI_V4MAPPED; > + > + if (gethostname(host, sizeof(host)) =3D=3D 0 > + && getaddrinfo(host, NULL, &hints, &info) =3D=3D 0 > + && info) { > + > + void *addr =3D NULL; > + char buff[INET6_ADDRSTRLEN + 1]; > + > + switch (info->ai_family) { > + case AF_INET: > + addr =3D &((struct sockaddr_in *) = info->ai_addr)->sin_addr; > + break; > + case AF_INET6: > + addr =3D &((struct sockaddr_in6 *) = info->ai_addr)->sin6_addr; > + break; > + } > + inet_ntop(info->ai_family, (void *) addr, buff, = sizeof(buff)); > + printf("%s", buff); > + > + freeaddrinfo(info); > + } > +} > + > static void output_special_char(unsigned char c, struct options *op, > struct termios *tp) > { > @@ -1808,6 +1880,26 @@ static void output_special_char(unsigned char = c, struct options *op, > printf((users =3D=3D 1) ? _("user") : = _("users")); > break; > } > + case 'x': > + if (op->interface) /* interface = name */ > + printf("%s", op->interface); > + break; > + case '4': > + case '6': > + { > + sa_family_t family =3D c =3D=3D '4' ? AF_INET : = AF_INET6; > + > + if (op->interface) { /* interface IP = */ > + struct ifaddrs *addrs; > + int status =3D getifaddrs(&addrs); > + if (status !=3D 0) > + break; > + output_iface_ip(addrs, op->interface, family); > + freeifaddrs(addrs); > + } else /* host IP */ > + output_ip(family); > + break; > + } > default: > putchar(c); > break; > --=20 > 1.7.7.6 >=20 ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH 0/2] agetty: display network address in issue 2012-09-12 17:29 ` Andrea Bonomi @ 2012-09-13 11:05 ` Karel Zak 0 siblings, 0 replies; 4+ messages in thread From: Karel Zak @ 2012-09-13 11:05 UTC (permalink / raw) To: Andrea Bonomi; +Cc: util-linux On Wed, Sep 12, 2012 at 07:29:19PM +0200, Andrea Bonomi wrote: > Hi, > good idea, much better without the hardcoded interface name. > I think that the --interface option is useful for the machine with a dynamic IP address. > (in my experience, the getaddrinfo based on the hostname returns the loopback address) > > Another idea will be to add the interface name after the \4 or \6, something like: > \4eth0 (or similar…) Excellent idea. It also means that --interface is unnecessary and more than one interface IP maybe be printed by the issue file. > to get the IPv4 address of the interface eth0 > So the user can specify the interface name directly in the issue file. > What do you think? Implemented, merged into master branch. For example: lo = \4{lo} em1 = \4{em1} (IPv6 \6{em1}) virbr0 = \4{virbr0} The {..} is optional argument, if not given, host IP is printed. Karel -- Karel Zak <kzak@redhat.com> http://karelzak.blogspot.com ^ permalink raw reply [flat|nested] 4+ messages in thread
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2012-08-15 9:08 ` [PATCH 0/2] agetty: display network address in issue Andrea Bonomi
2012-09-12 9:37 ` Karel Zak
2012-09-12 17:29 ` Andrea Bonomi
2012-09-13 11:05 ` Karel Zak
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