/prerequisites/yaz-3.0.52/src/http.c

/* This file is part of the YAZ toolkit.
 * Copyright (C) 1995-2009 Index Data
 * See the file LICENSE for details.
 */

/**
 * \file http.c
 * \brief Implements HTTP decoding
 */

#include <ctype.h>
#include <yaz/odr.h>
#include <yaz/yaz-version.h>
#include <yaz/yaz-iconv.h>
#include <yaz/matchstr.h>
#include <yaz/zgdu.h>

#ifdef WIN32
#define strncasecmp _strnicmp
#define strcasecmp _stricmp
#endif
 

/*
 * This function's counterpart, yaz_base64decode(), is in srwutil.c.
 * I feel bad that they're not together, but each function is only
 * needed in one place, and those places are not together.  Maybe one
 * day we'll move them into a new httputil.c, and declare them in a
 * corresponding httputil.h
 */
static void yaz_base64encode(const char *in, char *out)
{
    static char encoding[] =
        "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
    unsigned char buf[3];
    long n;

    while (*in != 0) {
	char *pad = 0;
        buf[0] = in[0];
	buf[1] = in[1];
	if (in[1] == 0) {
	    buf[2] = 0;
	    pad = "==";
	} else {
	    buf[2] = in[2];
	    if (in[2] == 0)
		pad = "=";
	}

	/* Treat three eight-bit numbers as on 24-bit number */
	n = (buf[0] << 16) + (buf[1] << 8) + buf[2];

	/* Write the six-bit chunks out as four encoded characters */
	*out++ = encoding[(n >> 18) & 63];
	*out++ = encoding[(n >> 12) & 63];
	if (in[1] != 0)
	    *out++ = encoding[(n >> 6) & 63];
	if (in[1] != 0 && in[2] != 0)
	    *out++ = encoding[n & 63];

	if (pad != 0) {
	    while (*pad != 0)
		*out++ = *pad++;
	    break;
	}
	in += 3;
    }

    *out++ = 0;
}


static int decode_headers_content(ODR o, int off, Z_HTTP_Header **headers,
                                  char **content_buf, int *content_len)
{
    int i = off;
    int chunked = 0;

    *headers = 0;
    while (i < o->size-1 && o->buf[i] == '\n')
    {
        int po;
        i++;
        if (o->buf[i] == '\r' && i < o->size-1 && o->buf[i+1] == '\n')
        {
            i++;
            break;
        }
        if (o->buf[i] == '\n')
            break;
        for (po = i; ; i++)
        {
            if (i == o->size)
            {
                o->error = OHTTP;
                return 0;
            }
            else if (o->buf[i] == ':')
                break;
        }
        *headers = (Z_HTTP_Header *) odr_malloc(o, sizeof(**headers));
        (*headers)->name = (char*) odr_malloc(o, i - po + 1);
        memcpy ((*headers)->name, o->buf + po, i - po);
        (*headers)->name[i - po] = '\0';
        i++;
        while (i < o->size-1 && o->buf[i] == ' ')
            i++;
        for (po = i; i < o->size-1 && !strchr("\r\n", o->buf[i]); i++)
            ;
        
        (*headers)->value = (char*) odr_malloc(o, i - po + 1);
        memcpy ((*headers)->value, o->buf + po, i - po);
        (*headers)->value[i - po] = '\0';
        
        if (!strcasecmp((*headers)->name, "Transfer-Encoding")
            &&
            !strcasecmp((*headers)->value, "chunked"))
            chunked = 1;
        headers = &(*headers)->next;
        if (i < o->size-1 && o->buf[i] == '\r')
            i++;
    }
    *headers = 0;
    if (o->buf[i] != '\n')
    {
        o->error = OHTTP;
        return 0;
    }
    i++;

    if (chunked)
    {
        int off = 0;
        
        /* we know buffer will be smaller than o->size - i*/
        *content_buf = (char*) odr_malloc(o, o->size - i);  
        
        while (1)
        {
            /* chunk length .. */
            int chunk_len = 0;
            for (; i  < o->size-2; i++)
                if (isdigit(o->buf[i]))
                    chunk_len = chunk_len * 16 + 
                        (o->buf[i] - '0');
                else if (isupper(o->buf[i]))
                    chunk_len = chunk_len * 16 + 
                        (o->buf[i] - ('A'-10));
                else if (islower(o->buf[i]))
                    chunk_len = chunk_len * 16 + 
                        (o->buf[i] - ('a'-10));
                else
                    break;
            /* chunk extension ... */
            while (o->buf[i] != '\r' && o->buf[i+1] != '\n')
            {
                if (i >= o->size-2)
                {
                    o->error = OHTTP;
                    return 0;
                }
                i++;
            }
            i += 2;  /* skip CRLF */
            if (chunk_len == 0)
                break;
            if (chunk_len < 0 || off + chunk_len > o->size)
            {
                o->error = OHTTP;
                return 0;
            }
            /* copy chunk .. */
            memcpy (*content_buf + off, o->buf + i, chunk_len);
            i += chunk_len + 2; /* skip chunk+CRLF */
            off += chunk_len;
        }
        if (!off)
            *content_buf = 0;
        *content_len = off;
    }
    else
    {
        if (i > o->size)
        {
            o->error = OHTTP;
            return 0;
        }
        else if (i == o->size)
        {
            *content_buf = 0;
            *content_len = 0;
        }
        else 
        {
            *content_len = o->size - i;
            *content_buf = (char*) odr_malloc(o, *content_len + 1);
            memcpy(*content_buf, o->buf + i, *content_len);
            (*content_buf)[*content_len] = '\0';
        }
    }
    return 1;
}

void z_HTTP_header_add_content_type(ODR o, Z_HTTP_Header **hp,
                                    const char *content_type,
                                    const char *charset)
{
    const char *l = "Content-Type";
    if (charset)
    {
        char *ctype = (char *)
            odr_malloc(o, strlen(content_type)+strlen(charset) + 15);
        sprintf(ctype, "%s; charset=%s", content_type, charset);
        z_HTTP_header_add(o, hp, l, ctype);
    }
    else
        z_HTTP_header_add(o, hp, l, content_type);

}

/*
 * HTTP Basic authentication is described at:
 * http://tools.ietf.org/html/rfc1945#section-11.1
 */
void z_HTTP_header_add_basic_auth(ODR o, Z_HTTP_Header **hp,
                                  const char *username, const char *password)
{
    char *tmp, *buf;
    int len;

    if (username == 0)
        return;

    len = strlen(username) + strlen(password);
    tmp = (char *) odr_malloc(o, len+2);
    sprintf(tmp, "%s:%s", username, password);
    buf = (char *) odr_malloc(o, (len+1) * 8/6 + 12);
    strcpy(buf, "Basic ");
    yaz_base64encode(tmp, &buf[strlen(buf)]);
    z_HTTP_header_add(o, hp, "Authorization", buf);
}


void z_HTTP_header_add(ODR o, Z_HTTP_Header **hp, const char *n,
                       const char *v)
{
    while (*hp)
        hp = &(*hp)->next;
    *hp = (Z_HTTP_Header *) odr_malloc(o, sizeof(**hp));
    (*hp)->name = odr_strdup(o, n);
    (*hp)->value = odr_strdup(o, v);
    (*hp)->next = 0;
}

const char *z_HTTP_header_lookup(const Z_HTTP_Header *hp, const char *n)
{
    for (; hp; hp = hp->next)
        if (!yaz_matchstr(hp->name, n))
            return hp->value;
    return 0;
}


Z_GDU *z_get_HTTP_Request(ODR o)
{
    Z_GDU *p = (Z_GDU *) odr_malloc(o, sizeof(*p));
    Z_HTTP_Request *hreq;

    p->which = Z_GDU_HTTP_Request;
    p->u.HTTP_Request = (Z_HTTP_Request *) odr_malloc(o, sizeof(*hreq));
    hreq = p->u.HTTP_Request;
    hreq->headers = 0;
    hreq->content_len = 0;
    hreq->content_buf = 0;
    hreq->version = "1.1";
    hreq->method = "POST";
    hreq->path = "/";
    z_HTTP_header_add(o, &hreq->headers, "User-Agent", "YAZ/" YAZ_VERSION);
    return p;
}


Z_GDU *z_get_HTTP_Request_host_path(ODR odr,
                                    const char *host,
                                    const char *path)
{
    Z_GDU *p = z_get_HTTP_Request(odr);

    p->u.HTTP_Request->path = odr_strdup(odr, path);

    if (host)
    {
        const char *cp0 = strstr(host, "://");
        const char *cp1 = 0;
        if (cp0)
            cp0 = cp0+3;
        else
            cp0 = host;

        cp1 = strchr(cp0, '/');
        if (!cp1)
            cp1 = cp0+strlen(cp0);

        if (cp0 && cp1)
        {
            char *h = (char*) odr_malloc(odr, cp1 - cp0 + 1);
            memcpy (h, cp0, cp1 - cp0);
            h[cp1-cp0] = '\0';
            z_HTTP_header_add(odr, &p->u.HTTP_Request->headers,
                              "Host", h);
        }
    }
    return p;
}


Z_GDU *z_get_HTTP_Response(ODR o, int code)
{
    Z_GDU *p = (Z_GDU *) odr_malloc(o, sizeof(*p));
    Z_HTTP_Response *hres;

    p->which = Z_GDU_HTTP_Response;
    p->u.HTTP_Response = (Z_HTTP_Response *) odr_malloc(o, sizeof(*hres));
    hres = p->u.HTTP_Response;
    hres->headers = 0;
    hres->content_len = 0;
    hres->content_buf = 0;
    hres->code = code;
    hres->version = "1.1";
    z_HTTP_header_add(o, &hres->headers, "Server",
                      "YAZ/" YAZ_VERSION);
    if (code != 200)
    {
        hres->content_buf = (char*) odr_malloc(o, 400);
        sprintf(hres->content_buf, 
                "<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\""
                " \"http://www.w3.org/TR/html4/strict.dtd\">\n"
                "<HTML>\n"
                " <HEAD>\n"
                "  <TITLE>YAZ " YAZ_VERSION "</TITLE>\n"
                " </HEAD>\n"
                " <BODY>\n"
                "  <P><A HREF=\"http://www.indexdata.com/yaz/\">YAZ</A> " 
                YAZ_VERSION "</P>\n"
                "  <P>Error: %d</P>\n"
                "  <P>Description: %.50s</P>\n"
                " </BODY>\n"
                "</HTML>\n",
                code, z_HTTP_errmsg(code));
        hres->content_len = strlen(hres->content_buf);
        z_HTTP_header_add(o, &hres->headers, "Content-Type", "text/html");
    }
    return p;
}

const char *z_HTTP_errmsg(int code)
{
    if (code == 200)
        return "OK";
    else if (code == 400)
        return "Bad Request";
    else if (code == 404)
        return "Not Found";
    else if (code == 405)
        return "Method Not Allowed";
    else if (code == 500)
        return "Internal Error";
    else
        return "Unknown Error";
}

int yaz_decode_http_response(ODR o, Z_HTTP_Response **hr_p)
{
    int i, po;
    Z_HTTP_Response *hr = (Z_HTTP_Response *) odr_malloc(o, sizeof(*hr));
    
    *hr_p = hr;
    hr->content_buf = 0;
    hr->content_len = 0;
    
    po = i = 5;
    while (i < o->size-2 && !strchr(" \r\n", o->buf[i]))
        i++;
    hr->version = (char *) odr_malloc(o, i - po + 1);
    if (i - po)
        memcpy(hr->version, o->buf + po, i - po);
    hr->version[i-po] = 0;
    if (o->buf[i] != ' ')
    {
        o->error = OHTTP;
        return 0;
    }
    i++;
    hr->code = 0;
    while (i < o->size-2 && o->buf[i] >= '0' && o->buf[i] <= '9')
    {
        hr->code = hr->code*10 + (o->buf[i] - '0');
        i++;
    }
    while (i < o->size-1 && o->buf[i] != '\n')
        i++;
    return decode_headers_content(o, i, &hr->headers,
                                  &hr->content_buf, &hr->content_len);            
}

int yaz_decode_http_request(ODR o, Z_HTTP_Request **hr_p)
{
    int i, po;
    Z_HTTP_Request *hr = (Z_HTTP_Request *) odr_malloc(o, sizeof(*hr));
    
    *hr_p = hr;
    
    /* method .. */
    for (i = 0; o->buf[i] != ' '; i++)
        if (i >= o->size-5 || i > 30)
        {
            o->error = OHTTP;
            return 0;
        }
    hr->method = (char *) odr_malloc(o, i+1);
    memcpy (hr->method, o->buf, i);
    hr->method[i] = '\0';
    /* path */
    po = i+1;
    for (i = po; o->buf[i] != ' '; i++)
        if (i >= o->size-5)
        {
            o->error = OHTTP;
            return 0;
        }
    hr->path = (char *) odr_malloc(o, i - po + 1);
    memcpy (hr->path, o->buf+po, i - po);
    hr->path[i - po] = '\0';
    /* HTTP version */
    i++;
    if (i > o->size-5 || memcmp(o->buf+i, "HTTP/", 5))
    {
        o->error = OHTTP;
        return 0;
    }
    i+= 5;
    po = i;
    while (i < o->size && !strchr("\r\n", o->buf[i]))
        i++;
    hr->version = (char *) odr_malloc(o, i - po + 1);
    memcpy(hr->version, o->buf + po, i - po);
    hr->version[i - po] = '\0';
    /* headers */
    if (i < o->size-1 && o->buf[i] == '\r')
        i++;
    if (o->buf[i] != '\n')
    {
        o->error = OHTTP;
        return 0;
    }
    return decode_headers_content(o, i, &hr->headers,
                                  &hr->content_buf, &hr->content_len);
}

int yaz_encode_http_response(ODR o, Z_HTTP_Response *hr)
{
    char sbuf[80];
    Z_HTTP_Header *h;
    int top0 = o->top;

    sprintf(sbuf, "HTTP/%s %d %s\r\n", hr->version,
            hr->code,
            z_HTTP_errmsg(hr->code));
    odr_write(o, (unsigned char *) sbuf, strlen(sbuf));
    /* apply Content-Length if not already applied */
    if (!z_HTTP_header_lookup(hr->headers,
                              "Content-Length"))
    {
        char lstr[60];
        sprintf(lstr, "Content-Length: %d\r\n",
                hr->content_len);
        odr_write(o, (unsigned char *) lstr, strlen(lstr));
    }
    for (h = hr->headers; h; h = h->next)
    {
        odr_write(o, (unsigned char *) h->name, strlen(h->name));
        odr_write(o, (unsigned char *) ": ", 2);
        odr_write(o, (unsigned char *) h->value, strlen(h->value));
        odr_write(o, (unsigned char *) "\r\n", 2);
    }
    odr_write(o, (unsigned char *) "\r\n", 2);
    if (hr->content_buf)
        odr_write(o, (unsigned char *) 
                  hr->content_buf,
                  hr->content_len);
    if (o->direction == ODR_PRINT)
    {
        odr_printf(o, "-- HTTP response:\n%.*s\n", o->top - top0,
                   o->buf + top0);
        odr_printf(o, "-- \n");
    }
    return 1;
}

int yaz_encode_http_request(ODR o, Z_HTTP_Request *hr)
{
    Z_HTTP_Header *h;
    int top0 = o->top;

    odr_write(o, (unsigned char *) hr->method,
              strlen(hr->method));
    odr_write(o, (unsigned char *) " ", 1);
    odr_write(o, (unsigned char *) hr->path,
              strlen(hr->path));
    odr_write(o, (unsigned char *) " HTTP/", 6);
    odr_write(o, (unsigned char *) hr->version,
              strlen(hr->version));
    odr_write(o, (unsigned char *) "\r\n", 2);
    if (hr->content_len &&
        !z_HTTP_header_lookup(hr->headers,
                              "Content-Length"))
    {
        char lstr[60];
        sprintf(lstr, "Content-Length: %d\r\n",
                hr->content_len);
        odr_write(o, (unsigned char *) lstr, strlen(lstr));
    }
    for (h = hr->headers; h; h = h->next)
    {
        odr_write(o, (unsigned char *) h->name, strlen(h->name));
        odr_write(o, (unsigned char *) ": ", 2);
        odr_write(o, (unsigned char *) h->value, strlen(h->value));
        odr_write(o, (unsigned char *) "\r\n", 2);
    }
    odr_write(o, (unsigned char *) "\r\n", 2);
    if (hr->content_buf)
        odr_write(o, (unsigned char *)
                  hr->content_buf,
                  hr->content_len);
    if (o->direction == ODR_PRINT)
    {
        odr_printf(o, "-- HTTP request:\n%.*s\n", o->top - top0,
                   o->buf + top0);
        odr_printf(o, "-- \n");
    }
    return 1;
}

/*
 * Local variables:
 * c-basic-offset: 4
 * c-file-style: "Stroustrup"
 * indent-tabs-mode: nil
 * End:
 * vim: shiftwidth=4 tabstop=8 expandtab
 */