cregit-Linux how code gets into the kernel

Release 4.8 net/ipv4/fou.c

Directory: net/ipv4
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/socket.h>
#include <linux/skbuff.h>
#include <linux/ip.h>
#include <linux/udp.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <net/genetlink.h>
#include <net/gue.h>
#include <net/ip.h>
#include <net/protocol.h>
#include <net/udp.h>
#include <net/udp_tunnel.h>
#include <net/xfrm.h>
#include <uapi/linux/fou.h>
#include <uapi/linux/genetlink.h>


struct fou {
	
struct socket *sock;
	
u8 protocol;
	
u8 flags;
	
__be16 port;
	
u8 family;
	
u16 type;
	
struct list_head list;
	
struct rcu_head rcu;
};


#define FOU_F_REMCSUM_NOPARTIAL BIT(0)


struct fou_cfg {
	
u16 type;
	
u8 protocol;
	
u8 flags;
	
struct udp_port_cfg udp_config;
};


static unsigned int fou_net_id;


struct fou_net {
	
struct list_head fou_list;
	
struct mutex fou_lock;
};


static inline struct fou *fou_from_sock(struct sock *sk) { return sk->sk_user_data; }

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tom herberttom herbert19100.00%1100.00%
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static int fou_recv_pull(struct sk_buff *skb, struct fou *fou, size_t len) { /* Remove 'len' bytes from the packet (UDP header and * FOU header if present). */ if (fou->family == AF_INET) ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(skb)->tot_len) - len); else ipv6_hdr(skb)->payload_len = htons(ntohs(ipv6_hdr(skb)->payload_len) - len); __skb_pull(skb, len); skb_postpull_rcsum(skb, udp_hdr(skb), len); skb_reset_transport_header(skb); return iptunnel_pull_offloads(skb); }

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static int fou_udp_recv(struct sock *sk, struct sk_buff *skb) { struct fou *fou = fou_from_sock(sk); if (!fou) return 1; if (fou_recv_pull(skb, fou, sizeof(struct udphdr))) goto drop; return -fou->protocol; drop: kfree_skb(skb); return 0; }

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tom herberttom herbert5276.47%375.00%
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static struct guehdr *gue_remcsum(struct sk_buff *skb, struct guehdr *guehdr, void *data, size_t hdrlen, u8 ipproto, bool nopartial) { __be16 *pd = data; size_t start = ntohs(pd[0]); size_t offset = ntohs(pd[1]); size_t plen = sizeof(struct udphdr) + hdrlen + max_t(size_t, offset + sizeof(u16), start); if (skb->remcsum_offload) return guehdr; if (!pskb_may_pull(skb, plen)) return NULL; guehdr = (struct guehdr *)&udp_hdr(skb)[1]; skb_remcsum_process(skb, (void *)guehdr + hdrlen, start, offset, nopartial); return guehdr; }

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static int gue_control_message(struct sk_buff *skb, struct guehdr *guehdr) { /* No support yet */ kfree_skb(skb); return 0; }

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tom herberttom herbert25100.00%2100.00%
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static int gue_udp_recv(struct sock *sk, struct sk_buff *skb) { struct fou *fou = fou_from_sock(sk); size_t len, optlen, hdrlen; struct guehdr *guehdr; void *data; u16 doffset = 0; if (!fou) return 1; len = sizeof(struct udphdr) + sizeof(struct guehdr); if (!pskb_may_pull(skb, len)) goto drop; guehdr = (struct guehdr *)&udp_hdr(skb)[1]; switch (guehdr->version) { case 0: /* Full GUE header present */ break; case 1: { /* Direct encasulation of IPv4 or IPv6 */ int prot; switch (((struct iphdr *)guehdr)->version) { case 4: prot = IPPROTO_IPIP; break; case 6: prot = IPPROTO_IPV6; break; default: goto drop; } if (fou_recv_pull(skb, fou, sizeof(struct udphdr))) goto drop; return -prot; } default: /* Undefined version */ goto drop; } optlen = guehdr->hlen << 2; len += optlen; if (!pskb_may_pull(skb, len)) goto drop; /* guehdr may change after pull */ guehdr = (struct guehdr *)&udp_hdr(skb)[1]; hdrlen = sizeof(struct guehdr) + optlen; if (guehdr->version != 0 || validate_gue_flags(guehdr, optlen)) goto drop; hdrlen = sizeof(struct guehdr) + optlen; if (fou->family == AF_INET) ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(skb)->tot_len) - len); else ipv6_hdr(skb)->payload_len = htons(ntohs(ipv6_hdr(skb)->payload_len) - len); /* Pull csum through the guehdr now . This can be used if * there is a remote checksum offload. */ skb_postpull_rcsum(skb, udp_hdr(skb), len); data = &guehdr[1]; if (guehdr->flags & GUE_FLAG_PRIV) { __be32 flags = *(__be32 *)(data + doffset); doffset += GUE_LEN_PRIV; if (flags & GUE_PFLAG_REMCSUM) { guehdr = gue_remcsum(skb, guehdr, data + doffset, hdrlen, guehdr->proto_ctype, !!(fou->flags & FOU_F_REMCSUM_NOPARTIAL)); if (!guehdr) goto drop; data = &guehdr[1]; doffset += GUE_PLEN_REMCSUM; } } if (unlikely(guehdr->control)) return gue_control_message(skb, guehdr); __skb_pull(skb, sizeof(struct udphdr) + hdrlen); skb_reset_transport_header(skb); if (iptunnel_pull_offloads(skb)) goto drop; return -guehdr->proto_ctype; drop: kfree_skb(skb); return 0; }

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tom herberttom herbert46095.44%777.78%
li rongqingli rongqing122.49%111.11%
jesse grossjesse gross102.07%111.11%
Total482100.00%9100.00%


static struct sk_buff **fou_gro_receive(struct sock *sk, struct sk_buff **head, struct sk_buff *skb) { const struct net_offload *ops; struct sk_buff **pp = NULL; u8 proto = fou_from_sock(sk)->protocol; const struct net_offload **offloads; /* We can clear the encap_mark for FOU as we are essentially doing * one of two possible things. We are either adding an L4 tunnel * header to the outer L3 tunnel header, or we are are simply * treating the GRE tunnel header as though it is a UDP protocol * specific header such as VXLAN or GENEVE. */ NAPI_GRO_CB(skb)->encap_mark = 0; /* Flag this frame as already having an outer encap header */ NAPI_GRO_CB(skb)->is_fou = 1; rcu_read_lock(); offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads; ops = rcu_dereference(offloads[proto]); if (!ops || !ops->callbacks.gro_receive) goto out_unlock; pp = ops->callbacks.gro_receive(head, skb); out_unlock: rcu_read_unlock(); return pp; }

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tom herberttom herbert11885.51%466.67%
alexander duyckalexander duyck2014.49%233.33%
Total138100.00%6100.00%


static int fou_gro_complete(struct sock *sk, struct sk_buff *skb, int nhoff) { const struct net_offload *ops; u8 proto = fou_from_sock(sk)->protocol; int err = -ENOSYS; const struct net_offload **offloads; rcu_read_lock(); offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads; ops = rcu_dereference(offloads[proto]); if (WARN_ON(!ops || !ops->callbacks.gro_complete)) goto out_unlock; err = ops->callbacks.gro_complete(skb, nhoff); skb_set_inner_mac_header(skb, nhoff); out_unlock: rcu_read_unlock(); return err; }

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tom herberttom herbert11394.17%266.67%
jarno rajahalmejarno rajahalme75.83%133.33%
Total120100.00%3100.00%


static struct guehdr *gue_gro_remcsum(struct sk_buff *skb, unsigned int off, struct guehdr *guehdr, void *data, size_t hdrlen, struct gro_remcsum *grc, bool nopartial) { __be16 *pd = data; size_t start = ntohs(pd[0]); size_t offset = ntohs(pd[1]); if (skb->remcsum_offload) return guehdr; if (!NAPI_GRO_CB(skb)->csum_valid) return NULL; guehdr = skb_gro_remcsum_process(skb, (void *)guehdr, off, hdrlen, start, offset, grc, nopartial); skb->remcsum_offload = 1; return guehdr; }

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tom herberttom herbert121100.00%8100.00%
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static struct sk_buff **gue_gro_receive(struct sock *sk, struct sk_buff **head, struct sk_buff *skb) { const struct net_offload **offloads; const struct net_offload *ops; struct sk_buff **pp = NULL; struct sk_buff *p; struct guehdr *guehdr; size_t len, optlen, hdrlen, off; void *data; u16 doffset = 0; int flush = 1; struct fou *fou = fou_from_sock(sk); struct gro_remcsum grc; u8 proto; skb_gro_remcsum_init(&grc); off = skb_gro_offset(skb); len = off + sizeof(*guehdr); guehdr = skb_gro_header_fast(skb, off); if (skb_gro_header_hard(skb, len)) { guehdr = skb_gro_header_slow(skb, len, off); if (unlikely(!guehdr)) goto out; } switch (guehdr->version) { case 0: break; case 1: switch (((struct iphdr *)guehdr)->version) { case 4: proto = IPPROTO_IPIP; break; case 6: proto = IPPROTO_IPV6; break; default: goto out; } goto next_proto; default: goto out; } optlen = guehdr->hlen << 2; len += optlen; if (skb_gro_header_hard(skb, len)) { guehdr = skb_gro_header_slow(skb, len, off); if (unlikely(!guehdr)) goto out; } if (unlikely(guehdr->control) || guehdr->version != 0 || validate_gue_flags(guehdr, optlen)) goto out; hdrlen = sizeof(*guehdr) + optlen; /* Adjust NAPI_GRO_CB(skb)->csum to account for guehdr, * this is needed if there is a remote checkcsum offload. */ skb_gro_postpull_rcsum(skb, guehdr, hdrlen); data = &guehdr[1]; if (guehdr->flags & GUE_FLAG_PRIV) { __be32 flags = *(__be32 *)(data + doffset); doffset += GUE_LEN_PRIV; if (flags & GUE_PFLAG_REMCSUM) { guehdr = gue_gro_remcsum(skb, off, guehdr, data + doffset, hdrlen, &grc, !!(fou->flags & FOU_F_REMCSUM_NOPARTIAL)); if (!guehdr) goto out; data = &guehdr[1]; doffset += GUE_PLEN_REMCSUM; } } skb_gro_pull(skb, hdrlen); for (p = *head; p; p = p->next) { const struct guehdr *guehdr2; if (!NAPI_GRO_CB(p)->same_flow) continue; guehdr2 = (struct guehdr *)(p->data + off); /* Compare base GUE header to be equal (covers * hlen, version, proto_ctype, and flags. */ if (guehdr->word != guehdr2->word) { NAPI_GRO_CB(p)->same_flow = 0; continue; } /* Compare optional fields are the same. */ if (guehdr->hlen && memcmp(&guehdr[1], &guehdr2[1], guehdr->hlen << 2)) { NAPI_GRO_CB(p)->same_flow = 0; continue; } } proto = guehdr->proto_ctype; next_proto: /* We can clear the encap_mark for GUE as we are essentially doing * one of two possible things. We are either adding an L4 tunnel * header to the outer L3 tunnel header, or we are are simply * treating the GRE tunnel header as though it is a UDP protocol * specific header such as VXLAN or GENEVE. */ NAPI_GRO_CB(skb)->encap_mark = 0; /* Flag this frame as already having an outer encap header */ NAPI_GRO_CB(skb)->is_fou = 1; rcu_read_lock(); offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads; ops = rcu_dereference(offloads[proto]); if (WARN_ON_ONCE(!ops || !ops->callbacks.gro_receive)) goto out_unlock; pp = ops->callbacks.gro_receive(head, skb); flush = 0; out_unlock: rcu_read_unlock(); out: NAPI_GRO_CB(skb)->flush |= flush; skb_gro_remcsum_cleanup(skb, &grc); return pp; }

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tom herberttom herbert61396.23%975.00%
alexander duyckalexander duyck243.77%325.00%
Total637100.00%12100.00%


static int gue_gro_complete(struct sock *sk, struct sk_buff *skb, int nhoff) { const struct net_offload **offloads; struct guehdr *guehdr = (struct guehdr *)(skb->data + nhoff); const struct net_offload *ops; unsigned int guehlen = 0; u8 proto; int err = -ENOENT; switch (guehdr->version) { case 0: proto = guehdr->proto_ctype; guehlen = sizeof(*guehdr) + (guehdr->hlen << 2); break; case 1: switch (((struct iphdr *)guehdr)->version) { case 4: proto = IPPROTO_IPIP; break; case 6: proto = IPPROTO_IPV6; break; default: return err; } break; default: return err; } rcu_read_lock(); offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads; ops = rcu_dereference(offloads[proto]); if (WARN_ON(!ops || !ops->callbacks.gro_complete)) goto out_unlock; err = ops->callbacks.gro_complete(skb, nhoff + guehlen); skb_set_inner_mac_header(skb, nhoff + guehlen); out_unlock: rcu_read_unlock(); return err; }

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tom herberttom herbert21196.79%480.00%
jarno rajahalmejarno rajahalme73.21%120.00%
Total218100.00%5100.00%


static int fou_add_to_port_list(struct net *net, struct fou *fou) { struct fou_net *fn = net_generic(net, fou_net_id); struct fou *fout; mutex_lock(&fn->fou_lock); list_for_each_entry(fout, &fn->fou_list, list) { if (fou->port == fout->port && fou->family == fout->family) { mutex_unlock(&fn->fou_lock); return -EALREADY; } } list_add(&fou->list, &fn->fou_list); mutex_unlock(&fn->fou_lock); return 0; }

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tom herberttom herbert7872.90%266.67%
americo wangamerico wang2927.10%133.33%
Total107100.00%3100.00%


static void fou_release(struct fou *fou) { struct socket *sock = fou->sock; list_del(&fou->list); udp_tunnel_sock_release(sock); kfree_rcu(fou, rcu); }

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hannes frederic sowahannes frederic sowa37.50%133.33%
americo wangamerico wang12.50%133.33%
Total40100.00%3100.00%


static int fou_create(struct net *net, struct fou_cfg *cfg, struct socket **sockp) { struct socket *sock = NULL; struct fou *fou = NULL; struct sock *sk; struct udp_tunnel_sock_cfg tunnel_cfg; int err; /* Open UDP socket */ err = udp_sock_create(net, &cfg->udp_config, &sock); if (err < 0) goto error; /* Allocate FOU port structure */ fou = kzalloc(sizeof(*fou), GFP_KERNEL); if (!fou) { err = -ENOMEM; goto error; } sk = sock->sk; fou->port = cfg->udp_config.local_udp_port; fou->family = cfg->udp_config.family; fou->flags = cfg->flags; fou->type = cfg->type; fou->sock = sock; memset(&tunnel_cfg, 0, sizeof(tunnel_cfg)); tunnel_cfg.encap_type = 1; tunnel_cfg.sk_user_data = fou; tunnel_cfg.encap_destroy = NULL; /* Initial for fou type */ switch (cfg->type) { case FOU_ENCAP_DIRECT: tunnel_cfg.encap_rcv = fou_udp_recv; tunnel_cfg.gro_receive = fou_gro_receive; tunnel_cfg.gro_complete = fou_gro_complete; fou->protocol = cfg->protocol; break; case FOU_ENCAP_GUE: tunnel_cfg.encap_rcv = gue_udp_recv; tunnel_cfg.gro_receive = gue_gro_receive; tunnel_cfg.gro_complete = gue_gro_complete; break; default: err = -EINVAL; goto error; } setup_udp_tunnel_sock(net, sock, &tunnel_cfg); sk->sk_allocation = GFP_ATOMIC; err = fou_add_to_port_list(net, fou); if (err) goto error; if (sockp) *sockp = sock; return 0; error: kfree(fou); if (sock) udp_tunnel_sock_release(sock); return err; }

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tom herberttom herbert30496.82%583.33%
americo wangamerico wang103.18%116.67%
Total314100.00%6100.00%


static int fou_destroy(struct net *net, struct fou_cfg *cfg) { struct fou_net *fn = net_generic(net, fou_net_id); __be16 port = cfg->udp_config.local_udp_port; u8 family = cfg->udp_config.family; int err = -EINVAL; struct fou *fou; mutex_lock(&fn->fou_lock); list_for_each_entry(fou, &fn->fou_list, list) { if (fou->port == port && fou->family == family) { fou_release(fou); err = 0; break; } } mutex_unlock(&fn->fou_lock); return err; }

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tom herberttom herbert9080.36%250.00%
americo wangamerico wang2219.64%250.00%
Total112100.00%4100.00%

static struct genl_family fou_nl_family = { .id = GENL_ID_GENERATE, .hdrsize = 0, .name = FOU_GENL_NAME, .version = FOU_GENL_VERSION, .maxattr = FOU_ATTR_MAX, .netnsok = true, }; static struct nla_policy fou_nl_policy[FOU_ATTR_MAX + 1] = { [FOU_ATTR_PORT] = { .type = NLA_U16, }, [FOU_ATTR_AF] = { .type = NLA_U8, }, [FOU_ATTR_IPPROTO] = { .type = NLA_U8, }, [FOU_ATTR_TYPE] = { .type = NLA_U8, }, [FOU_ATTR_REMCSUM_NOPARTIAL] = { .type = NLA_FLAG, }, };
static int parse_nl_config(struct genl_info *info, struct fou_cfg *cfg) { memset(cfg, 0, sizeof(*cfg)); cfg->udp_config.family = AF_INET; if (info->attrs[FOU_ATTR_AF]) { u8 family = nla_get_u8(info->attrs[FOU_ATTR_AF]); switch (family) { case AF_INET: break; case AF_INET6: cfg->udp_config.ipv6_v6only = 1; break; default: return -EAFNOSUPPORT; } cfg->udp_config.family = family; } if (info->attrs[FOU_ATTR_PORT]) { __be16 port = nla_get_be16(info->attrs[FOU_ATTR_PORT]); cfg->udp_config.local_udp_port = port; } if (info->