diff options
author | Matt Caswell <matt@openssl.org> | 2016-11-08 10:33:35 +0000 |
---|---|---|
committer | Matt Caswell <matt@openssl.org> | 2016-11-09 10:36:54 +0000 |
commit | 9b36b7d9bdb33d1edbc2bbfd8a773a0eb8645788 (patch) | |
tree | 668a1ea4172315f0ac08291bf9a44dc8bde80b8f /ssl/packet.c | |
parent | 327c1627923288d3dbbfc34d1c7d8785552f6ad8 (diff) |
Add support for initialising WPACKETs from a static buffer
Normally WPACKETs will use a BUF_MEM which can grow as required. Sometimes
though that may be overkill for what is needed - a static buffer may be
sufficient. This adds that capability.
Reviewed-by: Rich Salz <rsalz@openssl.org>
Diffstat (limited to 'ssl/packet.c')
-rw-r--r-- | ssl/packet.c | 55 |
1 files changed, 41 insertions, 14 deletions
diff --git a/ssl/packet.c b/ssl/packet.c index 27462e947e..5c5513314b 100644 --- a/ssl/packet.c +++ b/ssl/packet.c @@ -33,6 +33,9 @@ int WPACKET_sub_allocate_bytes__(WPACKET *pkt, size_t len, return 1; } +#define GETBUF(p) (((p)->staticbuf != NULL) \ + ? (p)->staticbuf : (unsigned char *)(p)->buf->data) + int WPACKET_reserve_bytes(WPACKET *pkt, size_t len, unsigned char **allocbytes) { /* Internal API, so should not fail */ @@ -43,7 +46,7 @@ int WPACKET_reserve_bytes(WPACKET *pkt, size_t len, unsigned char **allocbytes) if (pkt->maxsize - pkt->written < len) return 0; - if (pkt->buf->length - pkt->written < len) { + if (pkt->staticbuf == NULL && (pkt->buf->length - pkt->written < len)) { size_t newlen; size_t reflen; @@ -59,7 +62,7 @@ int WPACKET_reserve_bytes(WPACKET *pkt, size_t len, unsigned char **allocbytes) if (BUF_MEM_grow(pkt->buf, newlen) == 0) return 0; } - *allocbytes = (unsigned char *)pkt->buf->data + pkt->curr; + *allocbytes = GETBUF(pkt) + pkt->curr; return 1; } @@ -83,19 +86,12 @@ static size_t maxmaxsize(size_t lenbytes) return ((size_t)1 << (lenbytes * 8)) - 1 + lenbytes; } -int WPACKET_init_len(WPACKET *pkt, BUF_MEM *buf, size_t lenbytes) +static int wpacket_intern_init_len(WPACKET *pkt, size_t lenbytes) { unsigned char *lenchars; - /* Internal API, so should not fail */ - assert(buf != NULL); - if (buf == NULL) - return 0; - - pkt->buf = buf; pkt->curr = 0; pkt->written = 0; - pkt->maxsize = maxmaxsize(lenbytes); pkt->subs = OPENSSL_zalloc(sizeof(*pkt->subs)); if (pkt->subs == NULL) @@ -112,11 +108,42 @@ int WPACKET_init_len(WPACKET *pkt, BUF_MEM *buf, size_t lenbytes) pkt->subs = NULL; return 0; } - pkt->subs->packet_len = lenchars - (unsigned char *)pkt->buf->data; + pkt->subs->packet_len = lenchars - GETBUF(pkt); return 1; } +int WPACKET_init_static_len(WPACKET *pkt, unsigned char *buf, size_t len, + size_t lenbytes) +{ + size_t max = maxmaxsize(lenbytes); + + /* Internal API, so should not fail */ + assert(buf != NULL && len > 0); + if (buf == NULL || len == 0) + return 0; + + pkt->staticbuf = buf; + pkt->buf = NULL; + pkt->maxsize = (max < len) ? max : len; + + return wpacket_intern_init_len(pkt, lenbytes); +} + +int WPACKET_init_len(WPACKET *pkt, BUF_MEM *buf, size_t lenbytes) +{ + /* Internal API, so should not fail */ + assert(buf != NULL); + if (buf == NULL) + return 0; + + pkt->staticbuf = NULL; + pkt->buf = buf; + pkt->maxsize = maxmaxsize(lenbytes); + + return wpacket_intern_init_len(pkt, lenbytes); +} + int WPACKET_init(WPACKET *pkt, BUF_MEM *buf) { return WPACKET_init_len(pkt, buf, 0); @@ -179,8 +206,8 @@ static int wpacket_intern_close(WPACKET *pkt) /* Write out the WPACKET length if needed */ if (sub->lenbytes > 0 - && !put_value((unsigned char *)&pkt->buf->data[sub->packet_len], - packlen, sub->lenbytes)) + && !put_value(&GETBUF(pkt)[sub->packet_len], packlen, + sub->lenbytes)) return 0; pkt->subs = sub->parent; @@ -248,7 +275,7 @@ int WPACKET_start_sub_packet_len__(WPACKET *pkt, size_t lenbytes) if (!WPACKET_allocate_bytes(pkt, lenbytes, &lenchars)) return 0; /* Convert to an offset in case the underlying BUF_MEM gets realloc'd */ - sub->packet_len = lenchars - (unsigned char *)pkt->buf->data; + sub->packet_len = lenchars - GETBUF(pkt); return 1; } |