dump1090/net_io.c
Malcolm Robb 903f93f530 Publish Version 1.08.2705.14
A few minor additions and bug fixes as detailed below

1) Additional command line option "--net-buffer <n>" to specify the TCP
output buffer size. Default is n=0, which is 64Kb. Specify a value of n
to increase the buffer size according to  Size  = 64Kb * 2^n, so an n of
1 = 128Kb, n=2 is 256Kb etc. n is limited to 7, so the max size is 8Mb.
This option may assist if you have a high number of aircraft being
received, and an unreliable network connection, or if the receiving end
can be busy for an extended time.

2) Bug fix in ppup1090 which prevented the uploading of valid
ModeA/Squawk codes

3) Bug fix per Markus Grab's commit.
2014-05-27 13:16:57 +01:00

941 lines
32 KiB
C

// dump1090, a Mode S messages decoder for RTLSDR devices.
//
// Copyright (C) 2012 by Salvatore Sanfilippo <antirez@gmail.com>
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//
// * Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
#include "dump1090.h"
//
// ============================= Networking =============================
//
// Note: here we disregard any kind of good coding practice in favor of
// extreme simplicity, that is:
//
// 1) We only rely on the kernel buffers for our I/O without any kind of
// user space buffering.
// 2) We don't register any kind of event handler, from time to time a
// function gets called and we accept new connections. All the rest is
// handled via non-blocking I/O and manually polling clients to see if
// they have something new to share with us when reading is needed.
//
//=========================================================================
//
// Networking "stack" initialization
//
void modesInitNet(void) {
struct {
char *descr;
int *socket;
int port;
} services[MODES_NET_SERVICES_NUM] = {
{"Raw TCP output", &Modes.ros, Modes.net_output_raw_port},
{"Raw TCP input", &Modes.ris, Modes.net_input_raw_port},
{"Beast TCP output", &Modes.bos, Modes.net_output_beast_port},
{"Beast TCP input", &Modes.bis, Modes.net_input_beast_port},
{"HTTP server", &Modes.https, Modes.net_http_port},
{"Basestation TCP output", &Modes.sbsos, Modes.net_output_sbs_port}
};
int j;
Modes.clients = NULL;
#ifdef _WIN32
if ( (!Modes.wsaData.wVersion)
&& (!Modes.wsaData.wHighVersion) ) {
// Try to start the windows socket support
if (WSAStartup(MAKEWORD(2,1),&Modes.wsaData) != 0)
{
fprintf(stderr, "WSAStartup returned Error\n");
}
}
#endif
for (j = 0; j < MODES_NET_SERVICES_NUM; j++) {
int s = anetTcpServer(Modes.aneterr, services[j].port, NULL);
if (s == -1) {
fprintf(stderr, "Error opening the listening port %d (%s): %s\n",
services[j].port, services[j].descr, strerror(errno));
exit(1);
}
anetNonBlock(Modes.aneterr, s);
*services[j].socket = s;
}
#ifndef _WIN32
signal(SIGPIPE, SIG_IGN);
#endif
}
//
//=========================================================================
//
// This function gets called from time to time when the decoding thread is
// awakened by new data arriving. This usually happens a few times every second
//
struct client * modesAcceptClients(void) {
int fd, port;
unsigned int j;
struct client *c;
int services[6];
services[0] = Modes.ros;
services[1] = Modes.ris;
services[2] = Modes.bos;
services[3] = Modes.bis;
services[4] = Modes.https;
services[5] = Modes.sbsos;
for (j = 0; j < MODES_NET_SERVICES_NUM; j++) {
fd = anetTcpAccept(Modes.aneterr, services[j], NULL, &port);
if (fd == -1) continue;
anetNonBlock(Modes.aneterr, fd);
c = (struct client *) malloc(sizeof(*c));
c->service = services[j];
c->next = Modes.clients;
c->fd = fd;
c->buflen = 0;
Modes.clients = c;
anetSetSendBuffer(Modes.aneterr,fd, (MODES_NET_SNDBUF_SIZE << Modes.net_sndbuf_size));
if (services[j] == Modes.sbsos) Modes.stat_sbs_connections++;
if (services[j] == Modes.ros) Modes.stat_raw_connections++;
if (services[j] == Modes.bos) Modes.stat_beast_connections++;
j--; // Try again with the same listening port
if (Modes.debug & MODES_DEBUG_NET)
printf("Created new client %d\n", fd);
}
return Modes.clients;
}
//
//=========================================================================
//
// On error free the client, collect the structure, adjust maxfd if needed.
//
void modesFreeClient(struct client *c) {
// Unhook this client from the linked list of clients
struct client *p = Modes.clients;
if (p) {
if (p == c) {
Modes.clients = c->next;
} else {
while ((p) && (p->next != c)) {
p = p->next;
}
if (p) {
p->next = c->next;
}
}
}
// It's now safe to remove this client
close(c->fd);
if (c->service == Modes.sbsos) {
if (Modes.stat_sbs_connections) Modes.stat_sbs_connections--;
} else if (c->service == Modes.ros) {
if (Modes.stat_raw_connections) Modes.stat_raw_connections--;
} else if (c->service == Modes.bos) {
if (Modes.stat_beast_connections) Modes.stat_beast_connections--;
}
if (Modes.debug & MODES_DEBUG_NET)
printf("Closing client %d\n", c->fd);
free(c);
}
//
//=========================================================================
//
// Send the specified message to all clients listening for a given service
//
void modesSendAllClients(int service, void *msg, int len) {
struct client *c = Modes.clients;
while (c) {
// Read next before servicing client incase the service routine deletes the client!
struct client *next = c->next;
if (c->service == service) {
#ifndef _WIN32
int nwritten = write(c->fd, msg, len);
#else
int nwritten = send(c->fd, msg, len, 0 );
#endif
if (nwritten != len) {
modesFreeClient(c);
}
}
c = next;
}
}
//
//=========================================================================
//
// Write raw output in Beast Binary format with Timestamp to TCP clients
//
void modesSendBeastOutput(struct modesMessage *mm) {
char *p = &Modes.beastOut[Modes.beastOutUsed];
int msgLen = mm->msgbits / 8;
char * pTimeStamp;
char ch;
int j;
int iOutLen = msgLen + 9; // Escape, msgtype, timestamp, sigLevel, msg
*p++ = 0x1a;
if (msgLen == MODES_SHORT_MSG_BYTES)
{*p++ = '2';}
else if (msgLen == MODES_LONG_MSG_BYTES)
{*p++ = '3';}
else if (msgLen == MODEAC_MSG_BYTES)
{*p++ = '1';}
else
{return;}
pTimeStamp = (char *) &mm->timestampMsg;
for (j = 5; j >= 0; j--) {
*p++ = (ch = pTimeStamp[j]);
if (0x1A == ch) {*p++ = ch; iOutLen++;}
}
*p++ = (ch = mm->signalLevel);
if (0x1A == ch) {*p++ = ch; iOutLen++;}
for (j = 0; j < msgLen; j++) {
*p++ = (ch = mm->msg[j]);
if (0x1A == ch) {*p++ = ch; iOutLen++;}
}
Modes.beastOutUsed += iOutLen;
if (Modes.beastOutUsed >= Modes.net_output_raw_size)
{
modesSendAllClients(Modes.bos, Modes.beastOut, Modes.beastOutUsed);
Modes.beastOutUsed = 0;
Modes.net_output_raw_rate_count = 0;
}
}
//
//=========================================================================
//
// Write raw output to TCP clients
//
void modesSendRawOutput(struct modesMessage *mm) {
char *p = &Modes.rawOut[Modes.rawOutUsed];
int msgLen = mm->msgbits / 8;
int j;
unsigned char * pTimeStamp;
if (Modes.mlat && mm->timestampMsg) {
*p++ = '@';
pTimeStamp = (unsigned char *) &mm->timestampMsg;
for (j = 5; j >= 0; j--) {
sprintf(p, "%02X", pTimeStamp[j]);
p += 2;
}
Modes.rawOutUsed += 12; // additional 12 characters for timestamp
} else
*p++ = '*';
for (j = 0; j < msgLen; j++) {
sprintf(p, "%02X", mm->msg[j]);
p += 2;
}
*p++ = ';';
*p++ = '\n';
Modes.rawOutUsed += ((msgLen*2) + 3);
if (Modes.rawOutUsed >= Modes.net_output_raw_size)
{
modesSendAllClients(Modes.ros, Modes.rawOut, Modes.rawOutUsed);
Modes.rawOutUsed = 0;
Modes.net_output_raw_rate_count = 0;
}
}
//
//=========================================================================
//
// Write SBS output to TCP clients
// The message structure mm->bFlags tells us what has been updated by this message
//
void modesSendSBSOutput(struct modesMessage *mm) {
char msg[256], *p = msg;
uint32_t offset;
struct timeb epocTime;
struct tm stTime;
int msgType;
//
// SBS BS style output checked against the following reference
// http://www.homepages.mcb.net/bones/SBS/Article/Barebones42_Socket_Data.htm - seems comprehensive
//
// Decide on the basic SBS Message Type
if ((mm->msgtype == 4) || (mm->msgtype == 20)) {
msgType = 5;
} else if ((mm->msgtype == 5) || (mm->msgtype == 21)) {
msgType = 6;
} else if ((mm->msgtype == 0) || (mm->msgtype == 16)) {
msgType = 7;
} else if (mm->msgtype == 11) {
msgType = 8;
} else if ((mm->msgtype != 17) && (mm->msgtype != 18)) {
return;
} else if ((mm->metype >= 1) && (mm->metype <= 4)) {
msgType = 1;
} else if ((mm->metype >= 5) && (mm->metype <= 8)) {
if (mm->bFlags & MODES_ACFLAGS_LATLON_VALID)
{msgType = 2;}
else
{msgType = 7;}
} else if ((mm->metype >= 9) && (mm->metype <= 18)) {
if (mm->bFlags & MODES_ACFLAGS_LATLON_VALID)
{msgType = 3;}
else
{msgType = 7;}
} else if (mm->metype != 19) {
return;
} else if ((mm->mesub == 1) || (mm->mesub == 2)) {
msgType = 4;
} else {
return;
}
// Fields 1 to 6 : SBS message type and ICAO address of the aircraft and some other stuff
p += sprintf(p, "MSG,%d,111,11111,%06X,111111,", msgType, mm->addr);
// Fields 7 & 8 are the current time and date
if (mm->timestampMsg) { // Make sure the records' timestamp is valid before outputing it
epocTime = Modes.stSystemTimeBlk; // This is the time of the start of the Block we're processing
offset = (int) (mm->timestampMsg - Modes.timestampBlk); // This is the time (in 12Mhz ticks) into the Block
offset = offset / 12000; // convert to milliseconds
epocTime.millitm += offset; // add on the offset time to the Block start time
if (epocTime.millitm > 999) // if we've caused an overflow into the next second...
{epocTime.millitm -= 1000; epocTime.time ++;} // ..correct the overflow
stTime = *localtime(&epocTime.time); // convert the time to year, month day, hours, min, sec
p += sprintf(p, "%04d/%02d/%02d,", (stTime.tm_year+1900),(stTime.tm_mon+1), stTime.tm_mday);
p += sprintf(p, "%02d:%02d:%02d.%03d,", stTime.tm_hour, stTime.tm_min, stTime.tm_sec, epocTime.millitm);
} else {
p += sprintf(p, ",,");
}
// Fields 9 & 10 are the current time and date
ftime(&epocTime); // get the current system time & date
stTime = *localtime(&epocTime.time); // convert the time to year, month day, hours, min, sec
p += sprintf(p, "%04d/%02d/%02d,", (stTime.tm_year+1900),(stTime.tm_mon+1), stTime.tm_mday);
p += sprintf(p, "%02d:%02d:%02d.%03d", stTime.tm_hour, stTime.tm_min, stTime.tm_sec, epocTime.millitm);
// Field 11 is the callsign (if we have it)
if (mm->bFlags & MODES_ACFLAGS_CALLSIGN_VALID) {p += sprintf(p, ",%s", mm->flight);}
else {p += sprintf(p, ",");}
// Field 12 is the altitude (if we have it) - force to zero if we're on the ground
if ((mm->bFlags & MODES_ACFLAGS_AOG_GROUND) == MODES_ACFLAGS_AOG_GROUND) {
p += sprintf(p, ",0");
} else if (mm->bFlags & MODES_ACFLAGS_ALTITUDE_VALID) {
p += sprintf(p, ",%d", mm->altitude);
} else {
p += sprintf(p, ",");
}
// Field 13 and 14 are the ground Speed and Heading (if we have them)
if (mm->bFlags & MODES_ACFLAGS_NSEWSPD_VALID) {p += sprintf(p, ",%d,%d", mm->velocity, mm->heading);}
else {p += sprintf(p, ",,");}
// Fields 15 and 16 are the Lat/Lon (if we have it)
if (mm->bFlags & MODES_ACFLAGS_LATLON_VALID) {p += sprintf(p, ",%1.5f,%1.5f", mm->fLat, mm->fLon);}
else {p += sprintf(p, ",,");}
// Field 17 is the VerticalRate (if we have it)
if (mm->bFlags & MODES_ACFLAGS_VERTRATE_VALID) {p += sprintf(p, ",%d", mm->vert_rate);}
else {p += sprintf(p, ",");}
// Field 18 is the Squawk (if we have it)
if (mm->bFlags & MODES_ACFLAGS_SQUAWK_VALID) {p += sprintf(p, ",%x", mm->modeA);}
else {p += sprintf(p, ",");}
// Field 19 is the Squawk Changing Alert flag (if we have it)
if (mm->bFlags & MODES_ACFLAGS_FS_VALID) {
if ((mm->fs >= 2) && (mm->fs <= 4)) {
p += sprintf(p, ",-1");
} else {
p += sprintf(p, ",0");
}
} else {
p += sprintf(p, ",");
}
// Field 20 is the Squawk Emergency flag (if we have it)
if (mm->bFlags & MODES_ACFLAGS_SQUAWK_VALID) {
if ((mm->modeA == 0x7500) || (mm->modeA == 0x7600) || (mm->modeA == 0x7700)) {
p += sprintf(p, ",-1");
} else {
p += sprintf(p, ",0");
}
} else {
p += sprintf(p, ",");
}
// Field 21 is the Squawk Ident flag (if we have it)
if (mm->bFlags & MODES_ACFLAGS_FS_VALID) {
if ((mm->fs >= 4) && (mm->fs <= 5)) {
p += sprintf(p, ",-1");
} else {
p += sprintf(p, ",0");
}
} else {
p += sprintf(p, ",");
}
// Field 22 is the OnTheGround flag (if we have it)
if (mm->bFlags & MODES_ACFLAGS_AOG_VALID) {
if (mm->bFlags & MODES_ACFLAGS_AOG) {
p += sprintf(p, ",-1");
} else {
p += sprintf(p, ",0");
}
} else {
p += sprintf(p, ",");
}
p += sprintf(p, "\r\n");
modesSendAllClients(Modes.sbsos, msg, p-msg);
}
//
//=========================================================================
//
void modesQueueOutput(struct modesMessage *mm) {
if (Modes.stat_sbs_connections) {modesSendSBSOutput(mm);}
if (Modes.stat_beast_connections) {modesSendBeastOutput(mm);}
if (Modes.stat_raw_connections) {modesSendRawOutput(mm);}
}
//
//=========================================================================
//
// This function decodes a Beast binary format message
//
// The message is passed to the higher level layers, so it feeds
// the selected screen output, the network output and so forth.
//
// If the message looks invalid it is silently discarded.
//
// The function always returns 0 (success) to the caller as there is no
// case where we want broken messages here to close the client connection.
//
int decodeBinMessage(struct client *c, char *p) {
int msgLen = 0;
int j;
char ch;
unsigned char msg[MODES_LONG_MSG_BYTES];
struct modesMessage mm;
MODES_NOTUSED(c);
memset(&mm, 0, sizeof(mm));
if ((*p == '1') && (Modes.mode_ac)) { // skip ModeA/C unless user enables --modes-ac
msgLen = MODEAC_MSG_BYTES;
} else if (*p == '2') {
msgLen = MODES_SHORT_MSG_BYTES;
} else if (*p == '3') {
msgLen = MODES_LONG_MSG_BYTES;
}
if (msgLen) {
// Mark messages received over the internet as remote so that we don't try to
// pass them off as being received by this instance when forwarding them
mm.remote = 1;
for (j = 0; j < 7; j++) { // Skip the message type and timestamp
ch = *p++;
if (0x1A == ch) {p++;}
}
mm.signalLevel = ch = *p++; // Grab the signal level
if (0x1A == ch) {p++;}
for (j = 0; j < msgLen; j++) { // and the data
msg[j] = ch = *p++;
if (0x1A == ch) {p++;}
}
if (msgLen == MODEAC_MSG_BYTES) { // ModeA or ModeC
decodeModeAMessage(&mm, ((msg[0] << 8) | msg[1]));
} else {
decodeModesMessage(&mm, msg);
}
useModesMessage(&mm);
}
return (0);
}
//
//=========================================================================
//
// Turn an hex digit into its 4 bit decimal value.
// Returns -1 if the digit is not in the 0-F range.
//
int hexDigitVal(int c) {
c = tolower(c);
if (c >= '0' && c <= '9') return c-'0';
else if (c >= 'a' && c <= 'f') return c-'a'+10;
else return -1;
}
//
//=========================================================================
//
// This function decodes a string representing message in raw hex format
// like: *8D4B969699155600E87406F5B69F; The string is null-terminated.
//
// The message is passed to the higher level layers, so it feeds
// the selected screen output, the network output and so forth.
//
// If the message looks invalid it is silently discarded.
//
// The function always returns 0 (success) to the caller as there is no
// case where we want broken messages here to close the client connection.
//
int decodeHexMessage(struct client *c, char *hex) {
int l = strlen(hex), j;
unsigned char msg[MODES_LONG_MSG_BYTES];
struct modesMessage mm;
MODES_NOTUSED(c);
memset(&mm, 0, sizeof(mm));
// Mark messages received over the internet as remote so that we don't try to
// pass them off as being received by this instance when forwarding them
mm.remote = 1;
mm.signalLevel = 0xFF;
// Remove spaces on the left and on the right
while(l && isspace(hex[l-1])) {
hex[l-1] = '\0'; l--;
}
while(isspace(*hex)) {
hex++; l--;
}
// Turn the message into binary.
// Accept *-AVR raw @-AVR/BEAST timeS+raw %-AVR timeS+raw (CRC good) <-BEAST timeS+sigL+raw
// and some AVR records that we can understand
if (hex[l-1] != ';') {return (0);} // not complete - abort
switch(hex[0]) {
case '<': {
mm.signalLevel = (hexDigitVal(hex[13])<<4) | hexDigitVal(hex[14]);
hex += 15; l -= 16; // Skip <, timestamp and siglevel, and ;
break;}
case '@': // No CRC check
case '%': { // CRC is OK
hex += 13; l -= 14; // Skip @,%, and timestamp, and ;
break;}
case '*':
case ':': {
hex++; l-=2; // Skip * and ;
break;}
default: {
return (0); // We don't know what this is, so abort
break;}
}
if ( (l != (MODEAC_MSG_BYTES * 2))
&& (l != (MODES_SHORT_MSG_BYTES * 2))
&& (l != (MODES_LONG_MSG_BYTES * 2)) )
{return (0);} // Too short or long message... broken
if ( (0 == Modes.mode_ac)
&& (l == (MODEAC_MSG_BYTES * 2)) )
{return (0);} // Right length for ModeA/C, but not enabled
for (j = 0; j < l; j += 2) {
int high = hexDigitVal(hex[j]);
int low = hexDigitVal(hex[j+1]);
if (high == -1 || low == -1) return 0;
msg[j/2] = (high << 4) | low;
}
if (l == (MODEAC_MSG_BYTES * 2)) { // ModeA or ModeC
decodeModeAMessage(&mm, ((msg[0] << 8) | msg[1]));
} else { // Assume ModeS
decodeModesMessage(&mm, msg);
}
useModesMessage(&mm);
return (0);
}
//
//=========================================================================
//
// Return a description of planes in json. No metric conversion
//
char *aircraftsToJson(int *len) {
time_t now = time(NULL);
struct aircraft *a = Modes.aircrafts;
int buflen = 1024; // The initial buffer is incremented as needed
char *buf = (char *) malloc(buflen), *p = buf;
int l;
l = snprintf(p,buflen,"[\n");
p += l; buflen -= l;
while(a) {
int position = 0;
int track = 0;
if (a->modeACflags & MODEAC_MSG_FLAG) { // skip any fudged ICAO records Mode A/C
a = a->next;
continue;
}
if (a->bFlags & MODES_ACFLAGS_LATLON_VALID) {
position = 1;
}
if (a->bFlags & MODES_ACFLAGS_HEADING_VALID) {
track = 1;
}
// No metric conversion
l = snprintf(p,buflen,
"{\"hex\":\"%06x\", \"squawk\":\"%04x\", \"flight\":\"%s\", \"lat\":%f, "
"\"lon\":%f, \"validposition\":%d, \"altitude\":%d, \"vert_rate\":%d,\"track\":%d, \"validtrack\":%d,"
"\"speed\":%d, \"messages\":%ld, \"seen\":%d},\n",
a->addr, a->modeA, a->flight, a->lat, a->lon, position, a->altitude, a->vert_rate, a->track, track,
a->speed, a->messages, (int)(now - a->seen));
p += l; buflen -= l;
//Resize if needed
if (buflen < 256) {
int used = p-buf;
buflen += 1024; // Our increment.
buf = (char *) realloc(buf,used+buflen);
p = buf+used;
}
a = a->next;
}
//Remove the final comma if any, and closes the json array.
if (*(p-2) == ',') {
*(p-2) = '\n';
p--;
buflen++;
}
l = snprintf(p,buflen,"]\n");
p += l; buflen -= l;
*len = p-buf;
return buf;
}
//
//=========================================================================
//
#define MODES_CONTENT_TYPE_HTML "text/html;charset=utf-8"
#define MODES_CONTENT_TYPE_CSS "text/css;charset=utf-8"
#define MODES_CONTENT_TYPE_JSON "application/json;charset=utf-8"
#define MODES_CONTENT_TYPE_JS "application/javascript;charset=utf-8"
//
// Get an HTTP request header and write the response to the client.
// gain here we assume that the socket buffer is enough without doing
// any kind of userspace buffering.
//
// Returns 1 on error to signal the caller the client connection should
// be closed.
//
int handleHTTPRequest(struct client *c, char *p) {
char hdr[512];
int clen, hdrlen;
int httpver, keepalive;
char *url, *content;
char ctype[48];
char getFile[1024];
char *ext;
if (Modes.debug & MODES_DEBUG_NET)
printf("\nHTTP request: %s\n", c->buf);
// Minimally parse the request.
httpver = (strstr(p, "HTTP/1.1") != NULL) ? 11 : 10;
if (httpver == 10) {
// HTTP 1.0 defaults to close, unless otherwise specified.
keepalive = strstr(p, "Connection: keep-alive") != NULL;
} else if (httpver == 11) {
// HTTP 1.1 defaults to keep-alive, unless close is specified.
keepalive = strstr(p, "Connection: close") == NULL;
}
// Identify he URL.
p = strchr(p,' ');
if (!p) return 1; // There should be the method and a space
url = ++p; // Now this should point to the requested URL
p = strchr(p, ' ');
if (!p) return 1; // There should be a space before HTTP/
*p = '\0';
if (Modes.debug & MODES_DEBUG_NET) {
printf("\nHTTP keep alive: %d\n", keepalive);
printf("HTTP requested URL: %s\n\n", url);
}
if (strlen(url) < 2) {
snprintf(getFile, sizeof getFile, "%s/gmap.html", HTMLPATH); // Default file
} else {
snprintf(getFile, sizeof getFile, "%s/%s", HTMLPATH, url);
}
// Select the content to send, we have just two so far:
// "/" -> Our google map application.
// "/data.json" -> Our ajax request to update planes.
if (strstr(url, "/data.json")) {
content = aircraftsToJson(&clen);
//snprintf(ctype, sizeof ctype, MODES_CONTENT_TYPE_JSON);
} else {
struct stat sbuf;
int fd = -1;
if (stat(getFile, &sbuf) != -1 && (fd = open(getFile, O_RDONLY)) != -1) {
content = (char *) malloc(sbuf.st_size);
if (read(fd, content, sbuf.st_size) == -1) {
snprintf(content, sbuf.st_size, "Error reading from file: %s", strerror(errno));
}
clen = sbuf.st_size;
} else {
char buf[128];
clen = snprintf(buf,sizeof(buf),"Error opening HTML file: %s", strerror(errno));
content = strdup(buf);
}
if (fd != -1) {
close(fd);
}
}
// Get file extension and content type
snprintf(ctype, sizeof ctype, MODES_CONTENT_TYPE_HTML); // Default content type
ext = strrchr(getFile, '.');
if (strlen(ext) > 0) {
if (strstr(ext, ".json")) {
snprintf(ctype, sizeof ctype, MODES_CONTENT_TYPE_JSON);
} else if (strstr(ext, ".css")) {
snprintf(ctype, sizeof ctype, MODES_CONTENT_TYPE_CSS);
} else if (strstr(ext, ".js")) {
snprintf(ctype, sizeof ctype, MODES_CONTENT_TYPE_JS);
}
}
// Create the header and send the reply
hdrlen = snprintf(hdr, sizeof(hdr),
"HTTP/1.1 200 OK\r\n"
"Server: Dump1090\r\n"
"Content-Type: %s\r\n"
"Connection: %s\r\n"
"Content-Length: %d\r\n"
"Cache-Control: no-cache, must-revalidate\r\n"
"Expires: Sat, 26 Jul 1997 05:00:00 GMT\r\n"
"\r\n",
ctype,
keepalive ? "keep-alive" : "close",
clen);
if (Modes.debug & MODES_DEBUG_NET) {
printf("HTTP Reply header:\n%s", hdr);
}
// Send header and content.
#ifndef _WIN32
if ( (write(c->fd, hdr, hdrlen) != hdrlen)
|| (write(c->fd, content, clen) != clen) ) {
#else
if ( (send(c->fd, hdr, hdrlen, 0) != hdrlen)
|| (send(c->fd, content, clen, 0) != clen) ) {
#endif
free(content);
return 1;
}
free(content);
Modes.stat_http_requests++;
return !keepalive;
}
//
//=========================================================================
//
// This function polls the clients using read() in order to receive new
// messages from the net.
//
// The message is supposed to be separated from the next message by the
// separator 'sep', which is a null-terminated C string.
//
// Every full message received is decoded and passed to the higher layers
// calling the function's 'handler'.
//
// The handler returns 0 on success, or 1 to signal this function we should
// close the connection with the client in case of non-recoverable errors.
//
void modesReadFromClient(struct client *c, char *sep,
int(*handler)(struct client *, char *)) {
int left;
int nread;
int fullmsg;
int bContinue = 1;
char *s, *e, *p;
while(bContinue) {
fullmsg = 0;
left = MODES_CLIENT_BUF_SIZE - c->buflen;
// If our buffer is full discard it, this is some badly formatted shit
if (left <= 0) {
c->buflen = 0;
left = MODES_CLIENT_BUF_SIZE;
// If there is garbage, read more to discard it ASAP
}
#ifndef _WIN32
nread = read(c->fd, c->buf+c->buflen, left);
#else
nread = recv(c->fd, c->buf+c->buflen, left, 0);
if (nread < 0) {errno = WSAGetLastError();}
#endif
// If we didn't get all the data we asked for, then return once we've processed what we did get.
if (nread != left) {
bContinue = 0;
}
#ifndef _WIN32
if ( (nread < 0) && (errno != EAGAIN)) { // Error, or end of file
#else
if ( (nread < 0) && (errno != EWOULDBLOCK)) { // Error, or end of file
#endif
modesFreeClient(c);
}
if (nread <= 0) {
break; // Serve next client
}
c->buflen += nread;
// Always null-term so we are free to use strstr() (it won't affect binary case)
c->buf[c->buflen] = '\0';
e = s = c->buf; // Start with the start of buffer, first message
if (c->service == Modes.bis) {
// This is the Beast Binary scanning case.
// If there is a complete message still in the buffer, there must be the separator 'sep'
// in the buffer, note that we full-scan the buffer at every read for simplicity.
left = c->buflen; // Length of valid search for memchr()
while (left && ((s = memchr(e, (char) 0x1a, left)) != NULL)) { // The first byte of buffer 'should' be 0x1a
s++; // skip the 0x1a
if (*s == '1') {
e = s + MODEAC_MSG_BYTES + 8; // point past remainder of message
} else if (*s == '2') {
e = s + MODES_SHORT_MSG_BYTES + 8;
} else if (*s == '3') {
e = s + MODES_LONG_MSG_BYTES + 8;
} else {
e = s; // Not a valid beast message, skip
left = &(c->buf[c->buflen]) - e;
continue;
}
// we need to be careful of double escape characters in the message body
for (p = s; p < e; p++) {
if (0x1A == *p) {
p++; e++;
if (e > &(c->buf[c->buflen])) {
break;
}
}
}
left = &(c->buf[c->buflen]) - e;
if (left < 0) { // Incomplete message in buffer
e = s - 1; // point back at last found 0x1a.
break;
}
// Have a 0x1a followed by 1, 2 or 3 - pass message less 0x1a to handler.
if (handler(c, s)) {
modesFreeClient(c);
return;
}
fullmsg = 1;
}
s = e; // For the buffer remainder below
} else {
//
// This is the ASCII scanning case, AVR RAW or HTTP at present
// If there is a complete message still in the buffer, there must be the separator 'sep'
// in the buffer, note that we full-scan the buffer at every read for simplicity.
//
while ((e = strstr(s, sep)) != NULL) { // end of first message if found
*e = '\0'; // The handler expects null terminated strings
if (handler(c, s)) { // Pass message to handler.
modesFreeClient(c); // Handler returns 1 on error to signal we .
return; // should close the client connection
}
s = e + strlen(sep); // Move to start of next message
fullmsg = 1;
}
}
if (fullmsg) { // We processed something - so
c->buflen = &(c->buf[c->buflen]) - s; // Update the unprocessed buffer length
memmove(c->buf, s, c->buflen); // Move what's remaining to the start of the buffer
} else { // If no message was decoded process the next client
break;
}
}
}
//
//=========================================================================
//
// Read data from clients. This function actually delegates a lower-level
// function that depends on the kind of service (raw, http, ...).
//
void modesReadFromClients(void) {
struct client *c = modesAcceptClients();
while (c) {
// Read next before servicing client incase the service routine deletes the client!
struct client *next = c->next;
if (c->service == Modes.ris) {
modesReadFromClient(c,"\n",decodeHexMessage);
} else if (c->service == Modes.bis) {
modesReadFromClient(c,"",decodeBinMessage);
} else if (c->service == Modes.https) {
modesReadFromClient(c,"\r\n\r\n",handleHTTPRequest);
}
c = next;
}
}
//
// =============================== Network IO ===========================
//