From 70772c909199ad6701dc25593bc185938fa4cd23 Mon Sep 17 00:00:00 2001 From: Neil Jerram Date: Wed, 11 Jun 2014 21:22:40 +0100 Subject: Allow wildcard aliases in --bridge-interface option This is useful when using dnsmasq as DHCP server for a set of VMs whose data is routed by the host instead of being bridged. In this scenario: - There is an unbounded set of TAP interfaces that have no IP address at the host end. - DHCP allocation is done from an IPv4 address range associated with a dummy interface. - We run dnsmasq with --interface dummy --interface tap* --bind-dynamic, so that it listens on all the TAP interfaces, and --bridge-interface=dummy,tap*, so that it will allocate IP addresses via the TAP interfaces from the range associated with the dummy interface. --- man/dnsmasq.8 | 1 + man/fr/dnsmasq.8 | 2 +- src/dhcp.c | 2 +- src/dnsmasq.h | 1 + src/util.c | 19 +++++++++++++++++++ 5 files changed, 23 insertions(+), 2 deletions(-) diff --git a/man/dnsmasq.8 b/man/dnsmasq.8 index f25119d..0530a19 100644 --- a/man/dnsmasq.8 +++ b/man/dnsmasq.8 @@ -1550,6 +1550,7 @@ Treat DHCP request packets arriving at any of the interfaces as if they had arrived at . This option is necessary when using "old style" bridging on BSD platforms, since packets arrive at tap interfaces which don't have an IP address. +A trailing '*' wildcard can be used in each . .TP .B \-s, --domain=[,
[,local]] Specifies DNS domains for the DHCP server. Domains may be be given diff --git a/man/fr/dnsmasq.8 b/man/fr/dnsmasq.8 index 2f329ee..e0d1e9a 100644 --- a/man/fr/dnsmasq.8 +++ b/man/fr/dnsmasq.8 @@ -1659,7 +1659,7 @@ Traiter les requêtes DHCP arrivant sur n'importe laquelle des interfaces . Cette option est nécessaire lors de l'utilisation de pont ethernet "ancien mode" sur plate-forme BSD, puisque dans ce cas les paquets arrivent sur des interfaces "tap" n'ont -pas d'adresse IP. +pas d'adresse IP. Chaque peut finir avec un simple '*' joker. .TP .B \-s, --domain=[,[,local]] Spécifie le domaine du serveur DHCP. Le domaine peut être donné de manière diff --git a/src/dhcp.c b/src/dhcp.c index 9463e23..7acf2c4 100644 --- a/src/dhcp.c +++ b/src/dhcp.c @@ -232,7 +232,7 @@ void dhcp_packet(time_t now, int pxe_fd) for (bridge = daemon->bridges; bridge; bridge = bridge->next) { for (alias = bridge->alias; alias; alias = alias->next) - if (strncmp(ifr.ifr_name, alias->iface, IF_NAMESIZE) == 0) + if (wildcard_matchn(alias->iface, ifr.ifr_name, IF_NAMESIZE)) { if (!(iface_index = if_nametoindex(bridge->iface))) { diff --git a/src/dnsmasq.h b/src/dnsmasq.h index de98956..dfa9773 100644 --- a/src/dnsmasq.h +++ b/src/dnsmasq.h @@ -1150,6 +1150,7 @@ void bump_maxfd(int fd, int *max); int read_write(int fd, unsigned char *packet, int size, int rw); int wildcard_match(const char* wildcard, const char* match); +int wildcard_matchn(const char* wildcard, const char* match, int num); /* log.c */ void die(char *message, char *arg1, int exit_code); diff --git a/src/util.c b/src/util.c index 7c46d40..a503082 100644 --- a/src/util.c +++ b/src/util.c @@ -602,3 +602,22 @@ int wildcard_match(const char* wildcard, const char* match) return *wildcard == *match; } + +/* The same but comparing a maximum of NUM characters, like strncmp. */ +int wildcard_matchn(const char* wildcard, const char* match, int num) +{ + while (*wildcard && *match && num) + { + if (*wildcard == '*') + return 1; + + if (*wildcard != *match) + return 0; + + ++wildcard; + ++match; + --num; + } + + return (!num) || (*wildcard == *match); +} -- cgit v1.2.1