REORG: spoe: Move low-level encoding/decoding functions in dedicated header file
So, it will be easier to anyone to develop external services using these
functions.
SPOA example has been updated accordingly.
diff --git a/include/proto/spoe.h b/include/proto/spoe.h
new file mode 100644
index 0000000..06fb52d
--- /dev/null
+++ b/include/proto/spoe.h
@@ -0,0 +1,423 @@
+/*
+ * include/proto/spoe.h
+ * Encoding/Decoding functions for the SPOE filters (and other helpers).
+ *
+ * Copyright (C) 2017 HAProxy Technologies, Christopher Faulet <cfaulet@haproxy.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation, version 2.1
+ * exclusively.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef _PROTO_SPOE_H
+#define _PROTO_SPOE_H
+
+#include <types/spoe.h>
+
+#include <proto/sample.h>
+
+
+/* Encode the integer <i> into a varint (variable-length integer). The encoded
+ * value is copied in <*buf>. Here is the encoding format:
+ *
+ * 0 <= X < 240 : 1 byte (7.875 bits) [ XXXX XXXX ]
+ * 240 <= X < 2288 : 2 bytes (11 bits) [ 1111 XXXX ] [ 0XXX XXXX ]
+ * 2288 <= X < 264432 : 3 bytes (18 bits) [ 1111 XXXX ] [ 1XXX XXXX ] [ 0XXX XXXX ]
+ * 264432 <= X < 33818864 : 4 bytes (25 bits) [ 1111 XXXX ] [ 1XXX XXXX ]*2 [ 0XXX XXXX ]
+ * 33818864 <= X < 4328786160 : 5 bytes (32 bits) [ 1111 XXXX ] [ 1XXX XXXX ]*3 [ 0XXX XXXX ]
+ * ...
+ *
+ * On success, it returns the number of written bytes and <*buf> is moved after
+ * the encoded value. Otherwise, it returns -1. */
+int
+spoe_encode_varint(uint64_t i, char **buf, char *end)
+{
+ unsigned char *p = (unsigned char *)*buf;
+ int r;
+
+ if (p >= (unsigned char *)end)
+ return -1;
+
+ if (i < 240) {
+ *p++ = i;
+ *buf = (char *)p;
+ return 1;
+ }
+
+ *p++ = (unsigned char)i | 240;
+ i = (i - 240) >> 4;
+ while (i >= 128) {
+ if (p >= (unsigned char *)end)
+ return -1;
+ *p++ = (unsigned char)i | 128;
+ i = (i - 128) >> 7;
+ }
+
+ if (p >= (unsigned char *)end)
+ return -1;
+ *p++ = (unsigned char)i;
+
+ r = ((char *)p - *buf);
+ *buf = (char *)p;
+ return r;
+}
+
+/* Decode a varint from <*buf> and save the decoded value in <*i>. See
+ * 'spoe_encode_varint' for details about varint.
+ * On success, it returns the number of read bytes and <*buf> is moved after the
+ * varint. Otherwise, it returns -1. */
+int
+spoe_decode_varint(char **buf, char *end, uint64_t *i)
+{
+ unsigned char *p = (unsigned char *)*buf;
+ int r;
+
+ if (p >= (unsigned char *)end)
+ return -1;
+
+ *i = *p++;
+ if (*i < 240) {
+ *buf = (char *)p;
+ return 1;
+ }
+
+ r = 4;
+ do {
+ if (p >= (unsigned char *)end)
+ return -1;
+ *i += (uint64_t)*p << r;
+ r += 7;
+ } while (*p++ >= 128);
+
+ r = ((char *)p - *buf);
+ *buf = (char *)p;
+ return r;
+}
+
+/* Encode a buffer. Its length <len> is encoded as a varint, followed by a copy
+ * of <str>. It must have enough space in <*buf> to encode the buffer, else an
+ * error is triggered.
+ * On success, it returns <len> and <*buf> is moved after the encoded value. If
+ * an error occurred, it returns -1. */
+int
+spoe_encode_buffer(const char *str, size_t len, char **buf, char *end)
+{
+ char *p = *buf;
+ int ret;
+
+ if (p >= end)
+ return -1;
+
+ if (!len) {
+ *p++ = 0;
+ *buf = p;
+ return 0;
+ }
+
+ ret = spoe_encode_varint(len, &p, end);
+ if (ret == -1 || p + len > end)
+ return -1;
+
+ memcpy(p, str, len);
+ *buf = p + len;
+ return len;
+}
+
+/* Encode a buffer, possibly partially. It does the same thing than
+ * 'spoe_encode_buffer', but if there is not enough space, it does not fail.
+ * On success, it returns the number of copied bytes and <*buf> is moved after
+ * the encoded value. If an error occured, it returns -1. */
+int
+spoe_encode_frag_buffer(const char *str, size_t len, char **buf, char *end)
+{
+ char *p = *buf;
+ int ret;
+
+ if (p >= end)
+ return -1;
+
+ if (!len) {
+ *p++ = 0;
+ *buf = p;
+ return 0;
+ }
+
+ ret = spoe_encode_varint(len, &p, end);
+ if (ret == -1 || p >= end)
+ return -1;
+
+ ret = (p+len < end) ? len : (end - p);
+ memcpy(p, str, ret);
+ *buf = p + ret;
+ return ret;
+}
+
+/* Decode a buffer. The buffer length is decoded and saved in <*len>. <*str>
+ * points on the first byte of the buffer.
+ * On success, it returns the buffer length and <*buf> is moved after the
+ * encoded buffer. Otherwise, it returns -1. */
+int
+spoe_decode_buffer(char **buf, char *end, char **str, size_t *len)
+{
+ char *p = *buf;
+ uint64_t sz;
+ int ret;
+
+ *str = NULL;
+ *len = 0;
+
+ ret = spoe_decode_varint(&p, end, &sz);
+ if (ret == -1 || p + sz > end)
+ return -1;
+
+ *str = p;
+ *len = sz;
+ *buf = p + sz;
+ return sz;
+}
+
+/* Encode a typed data using value in <smp>. On success, it returns the number
+ * of copied bytes and <*buf> is moved after the encoded value. If an error
+ * occured, it returns -1.
+ *
+ * If the value is too big to be encoded, depending on its type, then encoding
+ * failed or the value is partially encoded. Only strings and binaries can be
+ * partially encoded. In this case, the offset <*off> is updated to known how
+ * many bytes has been encoded. If <*off> is zero at the end, it means that all
+ * data has been encoded. */
+int
+spoe_encode_data(struct sample *smp, unsigned int *off, char **buf, char *end)
+{
+ char *p = *buf;
+ int ret;
+
+ if (p >= end)
+ return -1;
+
+ if (smp == NULL) {
+ *p++ = SPOE_DATA_T_NULL;
+ goto end;
+ }
+
+ switch (smp->data.type) {
+ case SMP_T_BOOL:
+ *p = SPOE_DATA_T_BOOL;
+ *p++ |= ((!smp->data.u.sint) ? SPOE_DATA_FL_FALSE : SPOE_DATA_FL_TRUE);
+ break;
+
+ case SMP_T_SINT:
+ *p++ = SPOE_DATA_T_INT64;
+ if (spoe_encode_varint(smp->data.u.sint, &p, end) == -1)
+ return -1;
+ break;
+
+ case SMP_T_IPV4:
+ if (p + 5 > end)
+ return -1;
+ *p++ = SPOE_DATA_T_IPV4;
+ memcpy(p, &smp->data.u.ipv4, 4);
+ p += 4;
+ break;
+
+ case SMP_T_IPV6:
+ if (p + 17 > end)
+ return -1;
+ *p++ = SPOE_DATA_T_IPV6;
+ memcpy(p, &smp->data.u.ipv6, 16);
+ p += 16;
+ break;
+
+ case SMP_T_STR:
+ case SMP_T_BIN: {
+ struct chunk *chk = &smp->data.u.str;
+
+ /* Here, we need to know if the sample has already been
+ * partially encoded. If yes, we only need to encode the
+ * remaining, <*off> reprensenting the number of bytes
+ * already encoded. */
+ if (!*off) {
+ /* First evaluation of the sample : encode the
+ * type (string or binary), the buffer length
+ * (as a varint) and at least 1 byte of the
+ * buffer. */
+ struct chunk *chk = &smp->data.u.str;
+
+ *p++ = (smp->data.type == SMP_T_STR)
+ ? SPOE_DATA_T_STR
+ : SPOE_DATA_T_BIN;
+ ret = spoe_encode_frag_buffer(chk->str, chk->len, &p, end);
+ if (ret == -1)
+ return -1;
+ }
+ else {
+ /* The sample has been fragmented, encode remaining data */
+ ret = MIN(chk->len - *off, end - p);
+ memcpy(p, chk->str + *off, ret);
+ p += ret;
+ }
+ /* Now update <*off> */
+ if (ret + *off != chk->len)
+ *off += ret;
+ else
+ *off = 0;
+ break;
+ }
+
+ case SMP_T_METH: {
+ char *m;
+ size_t len;
+
+ *p++ = SPOE_DATA_T_STR;
+ switch (smp->data.u.meth.meth) {
+ case HTTP_METH_OPTIONS: m = "OPTIONS"; len = 7; break;
+ case HTTP_METH_GET : m = "GET"; len = 3; break;
+ case HTTP_METH_HEAD : m = "HEAD"; len = 4; break;
+ case HTTP_METH_POST : m = "POST"; len = 4; break;
+ case HTTP_METH_PUT : m = "PUT"; len = 3; break;
+ case HTTP_METH_DELETE : m = "DELETE"; len = 6; break;
+ case HTTP_METH_TRACE : m = "TRACE"; len = 5; break;
+ case HTTP_METH_CONNECT: m = "CONNECT"; len = 7; break;
+
+ default :
+ m = smp->data.u.meth.str.str;
+ len = smp->data.u.meth.str.len;
+ }
+ if (spoe_encode_buffer(m, len, &p, end) == -1)
+ return -1;
+ break;
+ }
+
+ default:
+ *p++ = SPOE_DATA_T_NULL;
+ break;
+ }
+
+ end:
+ ret = (p - *buf);
+ *buf = p;
+ return ret;
+}
+
+/* Skip a typed data. If an error occurred, -1 is returned, otherwise the number
+ * of skipped bytes is returned and the <*buf> is moved after skipped data.
+ *
+ * A types data is composed of a type (1 byte) and corresponding data:
+ * - boolean: non additional data (0 bytes)
+ * - integers: a variable-length integer (see spoe_decode_varint)
+ * - ipv4: 4 bytes
+ * - ipv6: 16 bytes
+ * - binary and string: a buffer prefixed by its size, a variable-length
+ * integer (see spoe_decode_buffer) */
+int
+spoe_skip_data(char **buf, char *end)
+{
+ char *str, *p = *buf;
+ int type, ret;
+ size_t sz;
+ uint64_t v;
+
+ if (p >= end)
+ return -1;
+
+ type = *p++;
+ switch (type & SPOE_DATA_T_MASK) {
+ case SPOE_DATA_T_BOOL:
+ break;
+ case SPOE_DATA_T_INT32:
+ case SPOE_DATA_T_INT64:
+ case SPOE_DATA_T_UINT32:
+ case SPOE_DATA_T_UINT64:
+ if (spoe_decode_varint(&p, end, &v) == -1)
+ return -1;
+ break;
+ case SPOE_DATA_T_IPV4:
+ if (p+4 > end)
+ return -1;
+ p += 4;
+ break;
+ case SPOE_DATA_T_IPV6:
+ if (p+16 > end)
+ return -1;
+ p += 16;
+ break;
+ case SPOE_DATA_T_STR:
+ case SPOE_DATA_T_BIN:
+ /* All the buffer must be skipped */
+ if (spoe_decode_buffer(&p, end, &str, &sz) == -1)
+ return -1;
+ break;
+ }
+
+ ret = (p - *buf);
+ *buf = p;
+ return ret;
+}
+
+/* Decode a typed data and fill <smp>. If an error occurred, -1 is returned,
+ * otherwise the number of read bytes is returned and <*buf> is moved after the
+ * decoded data. See spoe_skip_data for details. */
+int
+spoe_decode_data(char **buf, char *end, struct sample *smp)
+{
+ char *str, *p = *buf;
+ int type, r = 0;
+ size_t sz;
+
+ if (p >= end)
+ return -1;
+
+ type = *p++;
+ switch (type & SPOE_DATA_T_MASK) {
+ case SPOE_DATA_T_BOOL:
+ smp->data.u.sint = ((type & SPOE_DATA_FL_MASK) == SPOE_DATA_FL_TRUE);
+ smp->data.type = SMP_T_BOOL;
+ break;
+ case SPOE_DATA_T_INT32:
+ case SPOE_DATA_T_INT64:
+ case SPOE_DATA_T_UINT32:
+ case SPOE_DATA_T_UINT64:
+ if (spoe_decode_varint(&p, end, (uint64_t *)&smp->data.u.sint) == -1)
+ return -1;
+ smp->data.type = SMP_T_SINT;
+ break;
+ case SPOE_DATA_T_IPV4:
+ if (p+4 > end)
+ return -1;
+ smp->data.type = SMP_T_IPV4;
+ memcpy(&smp->data.u.ipv4, p, 4);
+ p += 4;
+ break;
+ case SPOE_DATA_T_IPV6:
+ if (p+16 > end)
+ return -1;
+ memcpy(&smp->data.u.ipv6, p, 16);
+ smp->data.type = SMP_T_IPV6;
+ p += 16;
+ break;
+ case SPOE_DATA_T_STR:
+ case SPOE_DATA_T_BIN:
+ /* All the buffer must be decoded */
+ if (spoe_decode_buffer(&p, end, &str, &sz) == -1)
+ return -1;
+ smp->data.u.str.str = str;
+ smp->data.u.str.len = sz;
+ smp->data.type = (type == SPOE_DATA_T_STR) ? SMP_T_STR : SMP_T_BIN;
+ break;
+ }
+
+ r = (p - *buf);
+ *buf = p;
+ return r;
+}
+
+#endif /* _PROTO_SPOE_H */