[net-next,2/2] sctp: add sctp_make_op_error_limited and reuse inner functions

Message ID	53909b1bd523d45a453431968fd1e03fd4be6196.1525017179.git.marcelo.leitner@gmail.com
State	Accepted, archived
Delegated to:	David Miller
Headers	show Return-Path: <netdev-owner@vger.kernel.org> From: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> To: netdev@vger.kernel.org Cc: linux-sctp@vger.kernel.org, Vlad Yasevich <vyasevich@gmail.com>, Neil Horman <nhorman@tuxdriver.com>, Xin Long <lucien.xin@gmail.com> Subject: [PATCH net-next 2/2] sctp: add sctp_make_op_error_limited and reuse inner functions Date: Sun, 29 Apr 2018 12:56:32 -0300 Message-Id: <53909b1bd523d45a453431968fd1e03fd4be6196.1525017179.git.marcelo.leitner@gmail.com> In-Reply-To: <cover.1525017179.git.marcelo.leitner@gmail.com> References: <cover.1525017179.git.marcelo.leitner@gmail.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk
Series	sctp: unify sctp_make_op_error_fixed and sctp_make_op_error_space \| expand [net-next,0/2] sctp: unify sctp_make_op_error_fixed and sctp_make_op_error_space [net-next,1/2] sctp: allow sctp_init_cause to return errors [net-next,2/2] sctp: add sctp_make_op_error_limited and reuse inner functions

diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c index e518eb64ccf3578f7892da050c160a56cf3cc833..4d7b3ccea0789f3a695f710046b50855e4cc41fc 100644 --- a/net/sctp/sm_make_chunk.c +++ b/net/sctp/sm_make_chunk.c @@ -81,8 +81,6 @@ static int sctp_process_param(struct sctp_association *asoc, gfp_t gfp); static void *sctp_addto_param(struct sctp_chunk *chunk, int len, const void *data); -static void *sctp_addto_chunk_fixed(struct sctp_chunk *, int len, - const void *data); /* Control chunk destructor */ static void sctp_control_release_owner(struct sk_buff *skb) @@ -154,9 +152,8 @@ static const struct sctp_paramhdr prsctp_param = { cpu_to_be16(sizeof(struct sctp_paramhdr)), }; -/* A helper to initialize an op error inside a - * provided chunk, as most cause codes will be embedded inside an - * abort chunk. +/* A helper to initialize an op error inside a provided chunk, as most + * cause codes will be embedded inside an abort chunk. */ int sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code, size_t paylen) @@ -177,29 +174,6 @@ int sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code, return 0; } -/* A helper to initialize an op error inside a - * provided chunk, as most cause codes will be embedded inside an - * abort chunk. Differs from sctp_init_cause in that it won't oops - * if there isn't enough space in the op error chunk - */ -static int sctp_init_cause_fixed(struct sctp_chunk *chunk, __be16 cause_code, - size_t paylen) -{ - struct sctp_errhdr err; - __u16 len; - - /* Cause code constants are now defined in network order. */ - err.cause = cause_code; - len = sizeof(err) + paylen; - err.length = htons(len); - - if (skb_tailroom(chunk->skb) < len) - return -ENOSPC; - - chunk->subh.err_hdr = sctp_addto_chunk_fixed(chunk, sizeof(err), &err); - - return 0; -} /* 3.3.2 Initiation (INIT) (1) * * This chunk is used to initiate a SCTP association between two @@ -1263,20 +1237,26 @@ static struct sctp_chunk *sctp_make_op_error_space( return retval; } -/* Create an Operation Error chunk of a fixed size, - * specifically, max(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) - * This is a helper function to allocate an error chunk for - * for those invalid parameter codes in which we may not want - * to report all the errors, if the incoming chunk is large +/* Create an Operation Error chunk of a fixed size, specifically, + * min(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) - overheads. + * This is a helper function to allocate an error chunk for for those + * invalid parameter codes in which we may not want to report all the + * errors, if the incoming chunk is large. If it can't fit in a single + * packet, we ignore it. */ -static inline struct sctp_chunk *sctp_make_op_error_fixed( +static inline struct sctp_chunk *sctp_make_op_error_limited( const struct sctp_association *asoc, const struct sctp_chunk *chunk) { - size_t size = asoc ? asoc->pathmtu : 0; + size_t size = SCTP_DEFAULT_MAXSEGMENT; + struct sctp_sock *sp = NULL; + + if (asoc) { + size = min_t(size_t, size, asoc->pathmtu); + sp = sctp_sk(asoc->base.sk); + } - if (!size) - size = SCTP_DEFAULT_MAXSEGMENT; + size = sctp_mtu_payload(sp, size, sizeof(struct sctp_errhdr)); return sctp_make_op_error_space(asoc, chunk, size); } @@ -1528,18 +1508,6 @@ void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data) return target; } -/* Append bytes to the end of a chunk. Returns NULL if there isn't sufficient - * space in the chunk - */ -static void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk, - int len, const void *data) -{ - if (skb_tailroom(chunk->skb) >= len) - return sctp_addto_chunk(chunk, len, data); - else - return NULL; -} - /* Append bytes from user space to the end of a chunk. Will panic if * chunk is not big enough. * Returns a kernel err value. @@ -1834,6 +1802,9 @@ struct sctp_association *sctp_unpack_cookie( kt = ktime_get_real(); if (!asoc && ktime_before(bear_cookie->expiration, kt)) { + suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration)); + __be32 n = htonl(usecs); + /* * Section 3.3.10.3 Stale Cookie Error (3) * @@ -1842,17 +1813,12 @@ struct sctp_association *sctp_unpack_cookie( * Stale Cookie Error: Indicates the receipt of a valid State * Cookie that has expired. */ - len = ntohs(chunk->chunk_hdr->length); - *errp = sctp_make_op_error_space(asoc, chunk, len); - if (*errp) { - suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration)); - __be32 n = htonl(usecs); - - sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE, - sizeof(n)); - sctp_addto_chunk(*errp, sizeof(n), &n); + *errp = sctp_make_op_error(asoc, chunk, + SCTP_ERROR_STALE_COOKIE, &n, + sizeof(n), 0); + if (*errp) *error = -SCTP_IERROR_STALE_COOKIE; - } else + else *error = -SCTP_IERROR_NOMEM; goto fail; @@ -2003,12 +1969,8 @@ static int sctp_process_hn_param(const struct sctp_association *asoc, if (*errp) sctp_chunk_free(*errp); - *errp = sctp_make_op_error_space(asoc, chunk, len); - - if (*errp) { - sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len); - sctp_addto_chunk(*errp, len, param.v); - } + *errp = sctp_make_op_error(asoc, chunk, SCTP_ERROR_DNS_FAILED, + param.v, len, 0); /* Stop processing this chunk. */ return 0; @@ -2133,23 +2095,23 @@ static enum sctp_ierror sctp_process_unk_param( /* Make an ERROR chunk, preparing enough room for * returning multiple unknown parameters. */ - if (NULL == *errp) - *errp = sctp_make_op_error_fixed(asoc, chunk); - - if (*errp) { - if (!sctp_init_cause_fixed(*errp, SCTP_ERROR_UNKNOWN_PARAM, - SCTP_PAD4(ntohs(param.p->length)))) - sctp_addto_chunk_fixed(*errp, - SCTP_PAD4(ntohs(param.p->length)), - param.v); - } else { - /* If there is no memory for generating the ERROR - * report as specified, an ABORT will be triggered - * to the peer and the association won't be - * established. - */ - retval = SCTP_IERROR_NOMEM; + if (!*errp) { + *errp = sctp_make_op_error_limited(asoc, chunk); + if (!*errp) { + /* If there is no memory for generating the + * ERROR report as specified, an ABORT will be + * triggered to the peer and the association + * won't be established. + */ + retval = SCTP_IERROR_NOMEM; + break; + } } + + if (!sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM, + ntohs(param.p->length))) + sctp_addto_chunk(*errp, ntohs(param.p->length), + param.v); break; default: break; @@ -2225,10 +2187,10 @@ static enum sctp_ierror sctp_verify_param(struct net *net, * MUST be aborted. The ABORT chunk SHOULD contain the error * cause 'Protocol Violation'. */ - if (SCTP_AUTH_RANDOM_LENGTH != - ntohs(param.p->length) - sizeof(struct sctp_paramhdr)) { + if (SCTP_AUTH_RANDOM_LENGTH != ntohs(param.p->length) - + sizeof(struct sctp_paramhdr)) { sctp_process_inv_paramlength(asoc, param.p, - chunk, err_chunk); + chunk, err_chunk); retval = SCTP_IERROR_ABORT; } break;

[net-next,2/2] sctp: add sctp_make_op_error_limited and reuse inner functions

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