vcpe/srcs/httpserver/src/haywire/picohttpparser.c

/*
 * Copyright (c) 2009-2014 Kazuho Oku, Tokuhiro Matsuno, Daisuke Murase,
 *                         Shigeo Mitsunari
 *
 * The software is licensed under either the MIT License (below) or the Perl
 * license.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */
#include <assert.h>
#include <stddef.h>
#include <string.h>
#ifdef __SSE4_2__
#ifdef _MSC_VER
#include <nmmintrin.h>
#else
#include <x86intrin.h>
#endif
#endif
#include "picohttpparser.h"

/* $Id$ */

#if __GNUC__ >= 3
#define likely(x)   __builtin_expect(!!(x), 1)
#define unlikely(x) __builtin_expect(!!(x), 0)
#else
#define likely(x)   (x)
#define unlikely(x) (x)
#endif

#ifdef _MSC_VER
#define ALIGNED(n) _declspec(align(n))
#else
#define ALIGNED(n) __attribute__((aligned(n)))
#endif

#define IS_PRINTABLE_ASCII(c) ((unsigned char)(c)-040u < 0137u)

#define CHECK_EOF()       \
    if (buf == buf_end) { \
        *ret = -2;        \
        return NULL;      \
    }

#define EXPECT_CHAR(ch) \
    CHECK_EOF();        \
    if (*buf++ != ch) { \
        *ret = -1;      \
        return NULL;    \
    }

#define ADVANCE_TOKEN(tok, toklen)                                                \
    do {                                                                          \
        const char       *tok_start             = buf;                            \
        static const char ALIGNED(16) ranges2[] = "\000\040\177\177";             \
        int               found2;                                                 \
        buf = findchar_fast(buf, buf_end, ranges2, sizeof(ranges2) - 1, &found2); \
        if (!found2) {                                                            \
            CHECK_EOF();                                                          \
        }                                                                         \
        while (1) {                                                               \
            if (*buf == ' ') {                                                    \
                break;                                                            \
            } else if (unlikely(!IS_PRINTABLE_ASCII(*buf))) {                     \
                if ((unsigned char)*buf < '\040' || *buf == '\177') {             \
                    *ret = -1;                                                    \
                    return NULL;                                                  \
                }                                                                 \
            }                                                                     \
            ++buf;                                                                \
            CHECK_EOF();                                                          \
        }                                                                         \
        tok    = tok_start;                                                       \
        toklen = buf - tok_start;                                                 \
    } while (0)

static const char *token_char_map =
    "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"
    "\0\1\1\1\1\1\1\1\0\0\1\1\0\1\1\0\1\1\1\1\1\1\1\1\1\1\0\0\0\0\0\0"
    "\0\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\0\0\0\1\1"
    "\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\0\1\0\1\0"
    "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"
    "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"
    "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"
    "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";

static const char *findchar_fast(const char *buf, const char *buf_end, const char *ranges, size_t ranges_size,
                                 int *found) {
    *found = 0;
#if __SSE4_2__
    if (likely(buf_end - buf >= 16)) {
        __m128i ranges16 = _mm_loadu_si128((const __m128i *)ranges);

        size_t left = (buf_end - buf) & ~15;
        do {
            __m128i b16 = _mm_loadu_si128((void *)buf);
            int     r   = _mm_cmpestri(
                ranges16, ranges_size, b16, 16, _SIDD_LEAST_SIGNIFICANT | _SIDD_CMP_RANGES | _SIDD_UBYTE_OPS);
            if (unlikely(r != 16)) {
                buf += r;
                *found = 1;
                break;
            }
            buf += 16;
            left -= 16;
        } while (likely(left != 0));
    }
#endif
    return buf;
}

static const char *get_token_to_eol(const char *buf, const char *buf_end, const char **token, size_t *token_len,
                                    int *ret) {
    const char *token_start = buf;

#ifdef __SSE4_2__
    static const char ranges1
        [] = "\0\010"
             /* allow HT */
             "\012\037"
             /* allow SP and up to but not including DEL */
             "\177\177"
        /* allow chars w. MSB set */
        ;
    int found;
    buf = findchar_fast(buf, buf_end, ranges1, sizeof(ranges1) - 1, &found);
    if (found)
        goto FOUND_CTL;
#else
    /* find non-printable char within the next 8 bytes, this is the hottest code; manually inlined */
    while (likely(buf_end - buf >= 8)) {
#define DOIT()                                   \
    do {                                         \
        if (unlikely(!IS_PRINTABLE_ASCII(*buf))) \
            goto NonPrintable;                   \
        ++buf;                                   \
    } while (0)
        DOIT();
        DOIT();
        DOIT();
        DOIT();
        DOIT();
        DOIT();
        DOIT();
        DOIT();
#undef DOIT
        continue;
    NonPrintable:
        if ((likely((unsigned char)*buf < '\040') && likely(*buf != '\011')) || unlikely(*buf == '\177')) {
            goto FOUND_CTL;
        }
        ++buf;
    }
#endif
    for (;; ++buf) {
        CHECK_EOF();
        if (unlikely(!IS_PRINTABLE_ASCII(*buf))) {
            if ((likely((unsigned char)*buf < '\040') && likely(*buf != '\011')) || unlikely(*buf == '\177')) {
                goto FOUND_CTL;
            }
        }
    }
FOUND_CTL:
    if (likely(*buf == '\015')) {
        ++buf;
        EXPECT_CHAR('\012');
        *token_len = buf - 2 - token_start;
    } else if (*buf == '\012') {
        *token_len = buf - token_start;
        ++buf;
    } else {
        *ret = -1;
        return NULL;
    }
    *token = token_start;

    return buf;
}

static const char *is_complete(const char *buf, const char *buf_end, size_t last_len, int *ret) {
    int ret_cnt = 0;
    buf         = last_len < 3 ? buf : buf + last_len - 3;

    while (1) {
        CHECK_EOF();
        if (*buf == '\015') {
            ++buf;
            CHECK_EOF();
            EXPECT_CHAR('\012');
            ++ret_cnt;
        } else if (*buf == '\012') {
            ++buf;
            ++ret_cnt;
        } else {
            ++buf;
            ret_cnt = 0;
        }
        if (ret_cnt == 2) {
            return buf;
        }
    }

    *ret = -2;
    return NULL;
}

/* *_buf is always within [buf, buf_end) upon success */
static const char *parse_int(const char *buf, const char *buf_end, int *value, int *ret) {
    int v;
    CHECK_EOF();
    if (!('0' <= *buf && *buf <= '9')) {
        *ret = -1;
        return NULL;
    }
    v = 0;
    for (;; ++buf) {
        CHECK_EOF();
        if ('0' <= *buf && *buf <= '9') {
            v = v * 10 + *buf - '0';
        } else {
            break;
        }
    }

    *value = v;
    return buf;
}

/* returned pointer is always within [buf, buf_end), or null */
static const char *parse_http_version(const char *buf, const char *buf_end, int *minor_version, int *ret) {
    EXPECT_CHAR('H');
    EXPECT_CHAR('T');
    EXPECT_CHAR('T');
    EXPECT_CHAR('P');
    EXPECT_CHAR('/');
    EXPECT_CHAR('1');
    EXPECT_CHAR('.');
    return parse_int(buf, buf_end, minor_version, ret);
}

static const char *parse_headers(const char *buf, const char *buf_end, struct phr_header *headers, size_t *num_headers,
                                 size_t max_headers, int *ret) {
    for (;; ++*num_headers) {
        CHECK_EOF();
        if (*buf == '\015') {
            ++buf;
            EXPECT_CHAR('\012');
            break;
        } else if (*buf == '\012') {
            ++buf;
            break;
        }
        if (*num_headers == max_headers) {
            *ret = -1;
            return NULL;
        }
        if (!(*num_headers != 0 && (*buf == ' ' || *buf == '\t'))) {
            if (!token_char_map[(unsigned char)*buf]) {
                *ret = -1;
                return NULL;
            }
            /* parsing name, but do not discard SP before colon, see
             * http://www.mozilla.org/security/announce/2006/mfsa2006-33.html */
            headers[*num_headers].name              = buf;
            static const char ALIGNED(16) ranges1[] = "::\x00\037";
            int               found;
            buf = findchar_fast(buf, buf_end, ranges1, sizeof(ranges1) - 1, &found);
            if (!found) {
                CHECK_EOF();
            }
            while (1) {
                if (*buf == ':') {
                    break;
                } else if (*buf < ' ') {
                    *ret = -1;
                    return NULL;
                }
                ++buf;
                CHECK_EOF();
            }
            headers[*num_headers].name_len = buf - headers[*num_headers].name;
            ++buf;
            for (;; ++buf) {
                CHECK_EOF();
                if (!(*buf == ' ' || *buf == '\t')) {
                    break;
                }
            }
        } else {
            headers[*num_headers].name     = NULL;
            headers[*num_headers].name_len = 0;
        }
        if ((buf = get_token_to_eol(buf, buf_end, &headers[*num_headers].value, &headers[*num_headers].value_len, ret))
            == NULL) {
            return NULL;
        }
    }
    return buf;
}

static const char *parse_request(const char *buf, const char *buf_end, const char **method, size_t *method_len,
                                 const char **path, size_t *path_len, int *minor_version, struct phr_header *headers,
                                 size_t *num_headers, size_t max_headers, int *ret) {
    /* skip first empty line (some clients add CRLF after POST content) */
    CHECK_EOF();
    if (*buf == '\015') {
        ++buf;
        EXPECT_CHAR('\012');
    } else if (*buf == '\012') {
        ++buf;
    }

    /* parse request line */
    ADVANCE_TOKEN(*method, *method_len);
    ++buf;
    ADVANCE_TOKEN(*path, *path_len);
    ++buf;
    if ((buf = parse_http_version(buf, buf_end, minor_version, ret)) == NULL) {
        return NULL;
    }
    if (*buf == '\015') {
        ++buf;
        EXPECT_CHAR('\012');
    } else if (*buf == '\012') {
        ++buf;
    } else {
        *ret = -1;
        return NULL;
    }

    return parse_headers(buf, buf_end, headers, num_headers, max_headers, ret);
}

int phr_parse_request(const char *buf_start, size_t len, const char **method, size_t *method_len, const char **path,
                      size_t *path_len, int *minor_version, struct phr_header *headers, size_t *num_headers,
                      size_t last_len) {
    const char *buf = buf_start, *buf_end = buf_start + len;
    size_t      max_headers = *num_headers;
    int         r;

    *method        = NULL;
    *method_len    = 0;
    *path          = NULL;
    *path_len      = 0;
    *minor_version = -1;
    *num_headers   = 0;

    /* if last_len != 0, check if the request is complete (a fast countermeasure
       againt slowloris */
    if (last_len != 0 && is_complete(buf, buf_end, last_len, &r) == NULL) {
        return r;
    }

    if ((buf = parse_request(
             buf, buf_end, method, method_len, path, path_len, minor_version, headers, num_headers, max_headers, &r))
        == NULL) {
        return r;
    }

    return (int)(buf - buf_start);
}

static const char *parse_response(const char *buf, const char *buf_end, int *minor_version, int *status,
                                  const char **msg, size_t *msg_len, struct phr_header *headers, size_t *num_headers,
                                  size_t max_headers, int *ret) {
    /* parse "HTTP/1.x" */
    if ((buf = parse_http_version(buf, buf_end, minor_version, ret)) == NULL) {
        return NULL;
    }
    /* skip space */
    if (*buf++ != ' ') {
        *ret = -1;
        return NULL;
    }
    /* parse status code */
    if ((buf = parse_int(buf, buf_end, status, ret)) == NULL) {
        return NULL;
    }
    /* skip space */
    if (*buf++ != ' ') {
        *ret = -1;
        return NULL;
    }
    /* get message */
    if ((buf = get_token_to_eol(buf, buf_end, msg, msg_len, ret)) == NULL) {
        return NULL;
    }

    return parse_headers(buf, buf_end, headers, num_headers, max_headers, ret);
}

int phr_parse_response(const char *buf_start, size_t len, int *minor_version, int *status, const char **msg,
                       size_t *msg_len, struct phr_header *headers, size_t *num_headers, size_t last_len) {
    const char *buf = buf_start, *buf_end = buf + len;
    size_t      max_headers = *num_headers;
    int         r;

    *minor_version = -1;
    *status        = 0;
    *msg           = NULL;
    *msg_len       = 0;
    *num_headers   = 0;

    /* if last_len != 0, check if the response is complete (a fast countermeasure
       against slowloris */
    if (last_len != 0 && is_complete(buf, buf_end, last_len, &r) == NULL) {
        return r;
    }

    if ((buf = parse_response(buf, buf_end, minor_version, status, msg, msg_len, headers, num_headers, max_headers, &r))
        == NULL) {
        return r;
    }

    return (int)(buf - buf_start);
}

int phr_parse_headers(const char *buf_start, size_t len, struct phr_header *headers, size_t *num_headers,
                      size_t last_len) {
    const char *buf = buf_start, *buf_end = buf + len;
    size_t      max_headers = *num_headers;
    int         r;

    *num_headers = 0;

    /* if last_len != 0, check if the response is complete (a fast countermeasure
       against slowloris */
    if (last_len != 0 && is_complete(buf, buf_end, last_len, &r) == NULL) {
        return r;
    }

    if ((buf = parse_headers(buf, buf_end, headers, num_headers, max_headers, &r)) == NULL) {
        return r;
    }

    return (int)(buf - buf_start);
}

enum {
    CHUNKED_IN_CHUNK_SIZE,
    CHUNKED_IN_CHUNK_EXT,
    CHUNKED_IN_CHUNK_DATA,
    CHUNKED_IN_CHUNK_CRLF,
    CHUNKED_IN_TRAILERS_LINE_HEAD,
    CHUNKED_IN_TRAILERS_LINE_MIDDLE
};

static int decode_hex(int ch) {
    if ('0' <= ch && ch <= '9') {
        return ch - '0';
    } else if ('A' <= ch && ch <= 'F') {
        return ch - 'A' + 0xa;
    } else if ('a' <= ch && ch <= 'f') {
        return ch - 'a' + 0xa;
    } else {
        return -1;
    }
}

ssize_t phr_decode_chunked(struct phr_chunked_decoder *decoder, char *buf, size_t *_bufsz) {
    size_t  dst = 0, src = 0, bufsz = *_bufsz;
    ssize_t ret = -2; /* incomplete */

    while (1) {
        switch (decoder->_state) {
            case CHUNKED_IN_CHUNK_SIZE:
                for (;; ++src) {
                    int v;
                    if (src == bufsz)
                        goto Exit;
                    if ((v = decode_hex(buf[src])) == -1) {
                        if (decoder->_hex_count == 0) {
                            ret = -1;
                            goto Exit;
                        }
                        break;
                    }
                    if (decoder->_hex_count == sizeof(size_t) * 2) {
                        ret = -1;
                        goto Exit;
                    }
                    decoder->bytes_left_in_chunk = decoder->bytes_left_in_chunk * 16 + v;
                    ++decoder->_hex_count;
                }
                decoder->_hex_count = 0;
                decoder->_state     = CHUNKED_IN_CHUNK_EXT;
            /* fallthru */
            case CHUNKED_IN_CHUNK_EXT:
                /* RFC 7230 A.2 "Line folding in chunk extensions is disallowed" */
                for (;; ++src) {
                    if (src == bufsz)
                        goto Exit;
                    if (buf[src] == '\012')
                        break;
                }
                ++src;
                if (decoder->bytes_left_in_chunk == 0) {
                    if (decoder->consume_trailer) {
                        decoder->_state = CHUNKED_IN_TRAILERS_LINE_HEAD;
                        break;
                    } else {
                        goto Complete;
                    }
                }
                decoder->_state = CHUNKED_IN_CHUNK_DATA;
            /* fallthru */
            case CHUNKED_IN_CHUNK_DATA: {
                size_t avail = bufsz - src;
                if (avail < decoder->bytes_left_in_chunk) {
                    if (dst != src)
                        memmove(buf + dst, buf + src, avail);
                    src += avail;
                    dst += avail;
                    decoder->bytes_left_in_chunk -= avail;
                    goto Exit;
                }
                if (dst != src)
                    memmove(buf + dst, buf + src, decoder->bytes_left_in_chunk);
                src += decoder->bytes_left_in_chunk;
                dst += decoder->bytes_left_in_chunk;
                decoder->bytes_left_in_chunk = 0;
                decoder->_state              = CHUNKED_IN_CHUNK_CRLF;
            }
            /* fallthru */
            case CHUNKED_IN_CHUNK_CRLF:
                for (;; ++src) {
                    if (src == bufsz)
                        goto Exit;
                    if (buf[src] != '\015')
                        break;
                }
                if (buf[src] != '\012') {
                    ret = -1;
                    goto Exit;
                }
                ++src;
                decoder->_state = CHUNKED_IN_CHUNK_SIZE;
                break;
            case CHUNKED_IN_TRAILERS_LINE_HEAD:
                for (;; ++src) {
                    if (src == bufsz)
                        goto Exit;
                    if (buf[src] != '\015')
                        break;
                }
                if (buf[src++] == '\012')
                    goto Complete;
                decoder->_state = CHUNKED_IN_TRAILERS_LINE_MIDDLE;
            /* fallthru */
            case CHUNKED_IN_TRAILERS_LINE_MIDDLE:
                for (;; ++src) {
                    if (src == bufsz)
                        goto Exit;
                    if (buf[src] == '\012')
                        break;
                }
                ++src;
                decoder->_state = CHUNKED_IN_TRAILERS_LINE_HEAD;
                break;
            default:
                assert(!"decoder is corrupt");
        }
    }

Complete:
    ret = bufsz - src;
Exit:
    if (dst != src)
        memmove(buf + dst, buf + src, bufsz - src);
    *_bufsz = dst;
    return ret;
}

#undef CHECK_EOF
#undef EXPECT_CHAR
#undef ADVANCE_TOKEN