kernel/include/net/netns/ipv4.h, branch linux-3.0.y

net: ipv4: add IPPROTO_ICMP socket kind

2011-05-13T20:08:13Z

This patch adds IPPROTO_ICMP socket kind. It makes it possible to send ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages without any special privileges. In other words, the patch makes it possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In order not to increase the kernel's attack surface, the new functionality is disabled by default, but is enabled at bootup by supporting Linux distributions, optionally with restriction to a group or a group range (see below). Similar functionality is implemented in Mac OS X: http://www.manpagez.com/man/4/icmp/ A new ping socket is created with socket(PF_INET, SOCK_DGRAM, PROT_ICMP) Message identifiers (octets 4-5 of ICMP header) are interpreted as local ports. Addresses are stored in struct sockaddr_in. No port numbers are reserved for privileged processes, port 0 is reserved for API ("let the kernel pick a free number"). There is no notion of remote ports, remote port numbers provided by the user (e.g. in connect()) are ignored. Data sent and received include ICMP headers. This is deliberate to: 1) Avoid the need to transport headers values like sequence numbers by other means. 2) Make it easier to port existing programs using raw sockets. ICMP headers given to send() are checked and sanitized. The type must be ICMP_ECHO and the code must be zero (future extensions might relax this, see below). The id is set to the number (local port) of the socket, the checksum is always recomputed. ICMP reply packets received from the network are demultiplexed according to their id's, and are returned by recv() without any modifications. IP header information and ICMP errors of those packets may be obtained via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source quenches and redirects are reported as fake errors via the error queue (IP_RECVERR); the next hop address for redirects is saved to ee_info (in network order). socket(2) is restricted to the group range specified in "/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons. The existing code might be (in the unlikely case anyone needs it) extended rather easily to handle other similar pairs of ICMP messages (Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply etc.). Userspace ping util & patch for it: http://openwall.info/wiki/people/segoon/ping For Openwall GNU/*/Linux it was the last step on the road to the setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels) is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs: http://mirrors.kernel.org/openwall/Owl/current/iso/ Initially this functionality was written by Pavel Kankovsky for Linux 2.4.32, but unfortunately it was never made public. All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with the patch. PATCH v3: - switched to flowi4. - minor changes to be consistent with raw sockets code. PATCH v2: - changed ping_debug() to pr_debug(). - removed CONFIG_IP_PING. - removed ping_seq_fops.owner field (unused for procfs). - switched to proc_net_fops_create(). - switched to %pK in seq_printf(). PATCH v1: - fixed checksumming bug. - CAP_NET_RAW may not create icmp sockets anymore. RFC v2: - minor cleanups. - introduced sysctl'able group range to restrict socket(2). Signed-off-by: Vasiliy Kulikov Signed-off-by: David S. Miller

ipv4: Invalidate nexthop cache nh_saddr more correctly.

2011-03-25T00:42:21Z

Any operation that: 1) Brings up an interface 2) Adds an IP address to an interface 3) Deletes an IP address from an interface can potentially invalidate the nh_saddr value, requiring it to be recomputed. Perform the recomputation lazily using a generation ID. Reported-by: Julian Anastasov Signed-off-by: David S. Miller

netfilter: nf_conntrack: use is_vmalloc_addr()

2011-01-14T14:45:56Z

Use is_vmalloc_addr() in nf_ct_free_hashtable() and get rid of the vmalloc flags to indicate that a hash table has been allocated using vmalloc(). Signed-off-by: Patrick McHardy

ipv4: remove ip_rt_secret timer (v4)

2010-05-08T08:57:52Z

A while back there was a discussion regarding the rt_secret_interval timer. Given that we've had the ability to do emergency route cache rebuilds for awhile now, based on a statistical analysis of the various hash chain lengths in the cache, the use of the flush timer is somewhat redundant. This patch removes the rt_secret_interval sysctl, allowing us to rely solely on the statistical analysis mechanism to determine the need for route cache flushes. Signed-off-by: Neil Horman Acked-by: Eric Dumazet Signed-off-by: David S. Miller

ipv4: ipmr: support multiple tables

2010-04-13T21:49:34Z

This patch adds support for multiple independant multicast routing instances, named "tables". Userspace multicast routing daemons can bind to a specific table instance by issuing a setsockopt call using a new option MRT_TABLE. The table number is stored in the raw socket data and affects all following ipmr setsockopt(), getsockopt() and ioctl() calls. By default, a single table (RT_TABLE_DEFAULT) is created with a default routing rule pointing to it. Newly created pimreg devices have the table number appended ("pimregX"), with the exception of devices created in the default table, which are named just "pimreg" for compatibility reasons. Packets are directed to a specific table instance using routing rules, similar to how regular routing rules work. Currently iif, oif and mark are supported as keys, source and destination addresses could be supported additionally. Example usage: - bind pimd/xorp/... to a specific table: uint32_t table = 123; setsockopt(fd, IPPROTO_IP, MRT_TABLE, &table, sizeof(table)); - create routing rules directing packets to the new table: # ip mrule add iif eth0 lookup 123 # ip mrule add oif eth0 lookup 123 Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller

ipv4: ipmr: move mroute data into seperate structure

2010-04-13T21:49:34Z

Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller

ipv4: ipmr: convert struct mfc_cache to struct list_head

2010-04-13T21:49:33Z

Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller

ipv4: ipmr: move unres_queue and timer to per-namespace data

2010-04-13T21:49:32Z

The unres_queue is currently shared between all namespaces. Following patches will additionally allow to create multiple multicast routing tables in each namespace. Having a single shared queue for all these users seems to excessive, move the queue and the cleanup timer to the per-namespace data to unshare it. As a side-effect, this fixes a bug in the seq file iteration functions: the first entry returned is always from the current namespace, entries returned after that may belong to any namespace. Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller

Merge branch 'master' of /repos/git/net-next-2.6

2010-02-10T13:17:10Z

Signed-off-by: Patrick McHardy

netfilter: nf_conntrack: fix hash resizing with namespaces

2010-02-08T19:18:07Z

As noticed by Jon Masters , the conntrack hash size is global and not per namespace, but modifiable at runtime through /sys/module/nf_conntrack/hashsize. Changing the hash size will only resize the hash in the current namespace however, so other namespaces will use an invalid hash size. This can cause crashes when enlarging the hashsize, or false negative lookups when shrinking it. Move the hash size into the per-namespace data and only use the global hash size to initialize the per-namespace value when instanciating a new namespace. Additionally restrict hash resizing to init_net for now as other namespaces are not handled currently. Cc: stable@kernel.org Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller