2 * httpd.c: implementation of httpd.h.
10 /* --- Logic driving what the web server's responses are. --- */
12 enum { /* connctx states */
21 int datalen
, datasize
;
22 char *method
, *url
, *headers
, *auth
;
27 * Called when a new connection arrives on a listening socket.
28 * Returns a connctx for the new connection.
30 struct connctx
*new_connection(const void *t
)
32 struct connctx
*cctx
= snew(struct connctx
);
35 cctx
->datalen
= cctx
->datasize
= 0;
36 cctx
->state
= READING_REQ_LINE
;
37 cctx
->method
= cctx
->url
= cctx
->headers
= cctx
->auth
= NULL
;
41 void free_connection(struct connctx
*cctx
)
47 static char *http_error(char *code
, char *errmsg
, char *extraheader
,
50 return dupfmt("HTTP/1.1 %s %s\r\n"
52 "Server: " PNAME
"\r\n"
53 "Connection: close\r\n"
55 "Content-Type: text/html; charset=US-ASCII\r\n"
57 "<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">\r\n"
59 "<TITLE>%s %s</TITLE>\r\n"
63 "</BODY></HTML>\r\n", code
, errmsg
,
64 extraheader ? extraheader
: "",
65 code
, errmsg
, code
, errmsg
, errtext
);
68 static char *http_success(char *mimetype
, int stuff_cr
, char *document
)
70 return dupfmt("HTTP/1.1 200 OK\r\n"
73 "Server: " PNAME
"\r\n"
74 "Connection: close\r\n"
75 "Content-Type: %s\r\n"
77 "%S", mimetype
, stuff_cr
, document
);
81 * Called when data comes in on a connection.
83 * If this function returns NULL, the platform code continues
84 * reading from the socket. Otherwise, it returns some dynamically
85 * allocated data which the platform code will then write to the
86 * socket before closing it.
88 char *got_data(struct connctx
*ctx
, char *data
, int length
,
89 int magic_access
, const char *auth_string
,
90 const struct html_config
*cfg
)
92 char *line
, *p
, *q
, *r
, *z1
, *z2
, c1
, c2
;
98 * Add the data we've just received to our buffer.
100 if (ctx
->datasize
< ctx
->datalen
+ length
) {
101 ctx
->datasize
= (ctx
->datalen
+ length
) * 3 / 2 + 4096;
102 ctx
->data
= sresize(ctx
->data
, ctx
->datasize
, char);
104 memcpy(ctx
->data
+ ctx
->datalen
, data
, length
);
105 ctx
->datalen
+= length
;
108 * Gradually process the HTTP request as we receive it.
110 if (ctx
->state
== READING_REQ_LINE
) {
112 * We're waiting for the first line of the input, which
113 * contains the main HTTP request. See if we've got it
119 * RFC 2616 section 4.1: `In the interest of robustness,
120 * [...] if the server is reading the protocol stream at
121 * the beginning of a message and receives a CRLF first,
122 * it should ignore the CRLF.'
124 while (line
- ctx
->data
< ctx
->datalen
&&
125 (*line
== '\r' || *line
== '\n'))
128 while (q
- ctx
->data
< ctx
->datalen
&& *q
!= '\n')
130 if (q
- ctx
->data
>= ctx
->datalen
)
131 return NULL
; /* not got request line yet */
134 * We've got the first line of the request. Zero-terminate
135 * and parse it into method, URL and optional HTTP
140 if (q
> line
&& q
[-1] == '\r')
145 while (*p
&& !isspace((unsigned char)*p
)) p
++;
151 while (*p
&& isspace((unsigned char)*p
)) p
++;
153 while (*q
&& !isspace((unsigned char)*q
)) q
++;
157 while (*q
&& isspace((unsigned char)*q
)) q
++;
160 * Now `line' points at the method name; p points at the
161 * URL, if any; q points at the HTTP version, if any.
165 * There should _be_ a URL, on any request type at all.
169 /* Restore the request to the way we received it. */
172 text
= dupfmt("<code>" PNAME
"</code> received the HTTP request"
173 " \"<code>%h</code>\", which contains no URL.",
175 ret
= http_error("400", "Bad request", NULL
, text
);
184 * If there was an HTTP version, we might need to see
185 * headers. Otherwise, the request is done.
188 ctx
->state
= READING_HEADERS
;
194 if (ctx
->state
== READING_HEADERS
) {
196 * While we're receiving the HTTP request headers, all we
197 * do is to keep scanning to see if we find two newlines
198 * next to each other.
200 q
= ctx
->data
+ ctx
->datalen
;
201 for (p
= ctx
->headers
; p
< q
; p
++) {
203 ((p
+1 < q
&& p
[1] == '\n') ||
204 (p
+2 < q
&& p
[1] == '\r' && p
[2] == '\n'))) {
212 if (ctx
->state
== DONE
) {
214 * Now we have the entire HTTP request. Decide what to do
219 * Search the request headers for Authorization.
221 q
= ctx
->data
+ ctx
->datalen
;
222 for (p
= ctx
->headers
; p
< q
; p
++) {
223 const char *hdr
= "Authorization:";
225 for (i
= 0; hdr
[i
]; i
++) {
226 if (p
>= q
|| tolower((unsigned char)*p
) !=
227 tolower((unsigned char)hdr
[i
]))
232 break; /* found our header */
233 p
= memchr(p
, '\n', q
- p
);
238 while (p
< q
&& isspace((unsigned char)*p
))
241 while (p
< q
&& !isspace((unsigned char)*p
))
245 if (!strcasecmp(r
, "Basic")) {
246 while (p
< q
&& isspace((unsigned char)*p
))
249 while (p
< q
&& !isspace((unsigned char)*p
))
253 if (!strcmp(r
, auth_string
))
261 if (!magic_access
&& !auth_correct
) {
263 ret
= http_error("401", "Unauthorized",
264 "WWW-Authenticate: Basic realm=\""PNAME
"\"\r\n",
265 "\nYou must authenticate to view these pages.");
267 ret
= http_error("403", "Forbidden", NULL
,
268 "This is a restricted-access set of pages.");
273 p
+= strspn(p
, "/?");
274 index
= strtoul(p
, &q
, 10);
276 ret
= http_error("404", "Not Found", NULL
,
277 "This is not a valid pathname index.");
279 document
= html_query(ctx
->t
, index
, cfg
, 1);
281 ret
= http_success("text/html", 1, document
);
284 ret
= http_error("404", "Not Found", NULL
,
285 "Pathname index out of range.");
294 /* --- Platform support for running a web server. --- */
296 enum { FD_CLIENT
, FD_LISTENER
, FD_CONNECTION
};
303 int wdatalen
, wdatapos
;
305 struct connctx
*cctx
;
308 struct fd
*fds
= NULL
;
309 int nfds
= 0, fdsize
= 0;
311 struct fd
*new_fdstruct(int fd
, int type
)
315 if (nfds
>= fdsize
) {
316 fdsize
= nfds
* 3 / 2 + 32;
317 fds
= sresize(fds
, fdsize
, struct fd
);
325 ret
->wdatalen
= ret
->wdatapos
= 0;
328 ret
->magic_access
= 0;
333 int check_owning_uid(int fd
, int flip
)
335 struct sockaddr_in sock
, peer
;
337 char linebuf
[4096], matchbuf
[80];
340 addrlen
= sizeof(sock
);
341 if (getsockname(fd
, (struct sockaddr
*)&sock
, &addrlen
)) {
342 fprintf(stderr
, "getsockname: %s\n", strerror(errno
));
345 addrlen
= sizeof(peer
);
346 if (getpeername(fd
, (struct sockaddr
*)&peer
, &addrlen
)) {
347 if (errno
== ENOTCONN
) {
348 peer
.sin_addr
.s_addr
= htonl(0);
349 peer
.sin_port
= htons(0);
351 fprintf(stderr
, "getpeername: %s\n", strerror(errno
));
357 struct sockaddr_in tmp
= sock
;
362 sprintf(matchbuf
, "%08X:%04X %08X:%04X",
363 peer
.sin_addr
.s_addr
, ntohs(peer
.sin_port
),
364 sock
.sin_addr
.s_addr
, ntohs(sock
.sin_port
));
365 fp
= fopen("/proc/net/tcp", "r");
367 while (fgets(linebuf
, sizeof(linebuf
), fp
)) {
368 if (strlen(linebuf
) >= 75 &&
369 !strncmp(linebuf
+6, matchbuf
, strlen(matchbuf
))) {
371 return atoi(linebuf
+ 75);
380 void check_magic_access(struct fd
*fd
)
382 if (check_owning_uid(fd
->fd
, 0) == getuid())
383 fd
->magic_access
= 1;
386 static void base64_encode_atom(unsigned char *data
, int n
, char *out
)
388 static const char base64_chars
[] =
389 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
393 word
= data
[0] << 16;
395 word
|= data
[1] << 8;
398 out
[0] = base64_chars
[(word
>> 18) & 0x3F];
399 out
[1] = base64_chars
[(word
>> 12) & 0x3F];
401 out
[2] = base64_chars
[(word
>> 6) & 0x3F];
405 out
[3] = base64_chars
[word
& 0x3F];
410 void run_httpd(const void *t
, int authmask
, const struct httpd_config
*dcfg
,
411 const struct html_config
*incfg
)
415 char *authstring
= NULL
;
416 struct sockaddr_in addr
;
418 struct html_config cfg
= *incfg
;
420 cfg
.format
= "%.0lu";
423 * Establish the listening socket and retrieve its port
426 fd
= socket(PF_INET
, SOCK_STREAM
, 0);
428 fprintf(stderr
, "socket(PF_INET): %s\n", strerror(errno
));
431 memset(&addr
, 0, sizeof(addr
));
432 addr
.sin_family
= AF_INET
;
433 if (!dcfg
->address
) {
434 #ifdef RANDOM_LOCALHOST
435 unsigned long ipaddr
;
438 ipaddr
+= (1 + rand() % 255) << 16;
439 ipaddr
+= (1 + rand() % 255) << 8;
440 ipaddr
+= (1 + rand() % 255);
441 addr
.sin_addr
.s_addr
= htonl(ipaddr
);
443 addr
.sin_addr
.s_addr
= htonl(INADDR_LOOPBACK
);
445 addr
.sin_port
= htons(0);
447 addr
.sin_addr
.s_addr
= inet_addr(dcfg
->address
);
448 addr
.sin_port
= dcfg
->port ?
htons(dcfg
->port
) : 0;
450 addrlen
= sizeof(addr
);
451 ret
= bind(fd
, (const struct sockaddr
*)&addr
, addrlen
);
452 #ifdef RANDOM_LOCALHOST
453 if (ret
< 0 && errno
== EADDRNOTAVAIL
&& !dcfg
->address
) {
455 * Some systems don't like us binding to random weird
456 * localhost-space addresses. Try again with the official
459 addr
.sin_addr
.s_addr
= htonl(INADDR_LOOPBACK
);
460 addr
.sin_port
= htons(0);
461 ret
= bind(fd
, (const struct sockaddr
*)&addr
, addrlen
);
465 fprintf(stderr
, "bind: %s\n", strerror(errno
));
468 if (listen(fd
, 5) < 0) {
469 fprintf(stderr
, "listen: %s\n", strerror(errno
));
472 addrlen
= sizeof(addr
);
473 if (getsockname(fd
, (struct sockaddr
*)&addr
, &addrlen
)) {
474 fprintf(stderr
, "getsockname: %s\n", strerror(errno
));
477 if ((authmask
& HTTPD_AUTH_MAGIC
) &&
478 (check_owning_uid(fd
, 1) == getuid())) {
479 authtype
= HTTPD_AUTH_MAGIC
;
480 if (authmask
!= HTTPD_AUTH_MAGIC
)
481 printf("Using Linux /proc/net magic authentication\n");
482 } else if ((authmask
& HTTPD_AUTH_BASIC
)) {
483 char username
[128], password
[128], userpassbuf
[259];
484 const char *userpass
;
486 unsigned char passbuf
[10];
489 authtype
= HTTPD_AUTH_BASIC
;
491 if (authmask
!= HTTPD_AUTH_BASIC
)
492 printf("Using HTTP Basic authentication\n");
494 if (dcfg
->basicauthdata
) {
495 userpass
= dcfg
->basicauthdata
;
497 strcpy(username
, PNAME
);
498 rname
= "/dev/urandom";
499 fd
= open(rname
, O_RDONLY
);
502 rname
= "/dev/random";
503 fd
= open(rname
, O_RDONLY
);
506 fprintf(stderr
, "/dev/urandom: open: %s\n", strerror(err
));
507 fprintf(stderr
, "/dev/random: open: %s\n", strerror(err2
));
511 for (i
= 0; i
< 10 ;) {
512 j
= read(fd
, passbuf
+ i
, 10 - i
);
514 fprintf(stderr
, "%s: read: %s\n", rname
,
515 j
< 0 ?
strerror(errno
) : "unexpected EOF");
521 for (i
= 0; i
< 16; i
++) {
523 * 32 characters out of the 36 alphanumerics gives
524 * me the latitude to discard i,l,o for being too
525 * numeric-looking, and w because it has two too
526 * many syllables and one too many presidential
529 static const char chars
[32] =
530 "0123456789abcdefghjkmnpqrstuvxyz";
534 for (j
= 0; j
< 5; j
++)
535 v
|= ((passbuf
[k
+j
] >> (i
%8)) & 1) << j
;
537 password
[i
] = chars
[v
];
541 sprintf(userpassbuf
, "%s:%s", username
, password
);
542 userpass
= userpassbuf
;
544 printf("Username: %s\nPassword: %s\n", username
, password
);
547 k
= strlen(userpass
);
548 authstring
= snewn(k
* 4 / 3 + 16, char);
549 for (i
= j
= 0; i
< k
;) {
550 int s
= k
-i
< 3 ? k
-i
: 3;
551 base64_encode_atom((unsigned char *)(userpass
+i
), s
, authstring
+j
);
555 authstring
[j
] = '\0';
556 } else if ((authmask
& HTTPD_AUTH_NONE
)) {
557 authtype
= HTTPD_AUTH_NONE
;
558 if (authmask
!= HTTPD_AUTH_NONE
)
559 printf("Web server is unauthenticated\n");
561 fprintf(stderr
, PNAME
": authentication method not supported\n");
564 if (ntohs(addr
.sin_addr
.s_addr
) == INADDR_ANY
) {
565 printf("Server port: %d\n", ntohs(addr
.sin_port
));
566 } else if (ntohs(addr
.sin_port
) == 80) {
567 printf("URL: http://%s/\n", inet_ntoa(addr
.sin_addr
));
569 printf("URL: http://%s:%d/\n",
570 inet_ntoa(addr
.sin_addr
), ntohs(addr
.sin_port
));
575 * Now construct an fd structure to hold it.
577 new_fdstruct(fd
, FD_LISTENER
);
579 if (dcfg
->closeoneof
) {
581 * Read from standard input, and treat EOF as a notification
584 new_fdstruct(0, FD_CLIENT
);
588 * Now we're ready to run our main loop. Keep looping round on
594 SELECT_TYPE_ARG1 maxfd
;
597 #define FD_SET_MAX(fd, set, max) \
598 do { FD_SET((fd),(set)); (max) = ((max)<=(fd)?(fd)+1:(max)); } while(0)
601 * Loop round the fd list putting fds into our select
602 * sets. Also in this loop we remove any that were marked
603 * as deleted in the previous loop.
608 for (i
= j
= 0; j
< nfds
; j
++) {
610 if (fds
[j
].deleted
) {
612 free_connection(fds
[j
].cctx
);
617 switch (fds
[i
].type
) {
619 FD_SET_MAX(fds
[i
].fd
, &rfds
, maxfd
);
622 FD_SET_MAX(fds
[i
].fd
, &rfds
, maxfd
);
626 * Always read from a connection socket. Even
627 * after we've started writing, the peer might
628 * still be sending (e.g. because we shamefully
629 * jumped the gun before waiting for the end of
630 * the HTTP request) and so we should be prepared
631 * to read data and throw it away.
633 FD_SET_MAX(fds
[i
].fd
, &rfds
, maxfd
);
635 * Also attempt to write, if we have data to write.
637 if (fds
[i
].wdatapos
< fds
[i
].wdatalen
)
638 FD_SET_MAX(fds
[i
].fd
, &wfds
, maxfd
);
646 ret
= select(maxfd
, SELECT_TYPE_ARG234
&rfds
,
647 SELECT_TYPE_ARG234
&wfds
, SELECT_TYPE_ARG234 NULL
,
648 SELECT_TYPE_ARG5 NULL
);
650 if (ret
< 0 && (errno
!= EINTR
)) {
651 fprintf(stderr
, "select: %s", strerror(errno
));
657 for (i
= 0; i
< nfds
; i
++) {
658 switch (fds
[i
].type
) {
660 if (FD_ISSET(fds
[i
].fd
, &rfds
)) {
662 int ret
= read(fds
[i
].fd
, buf
, sizeof(buf
));
665 fprintf(stderr
, "standard input: read: %s\n",
674 if (FD_ISSET(fds
[i
].fd
, &rfds
)) {
676 * New connection has come in. Accept it.
679 struct sockaddr_in addr
;
680 socklen_t addrlen
= sizeof(addr
);
681 int newfd
= accept(fds
[i
].fd
, (struct sockaddr
*)&addr
,
684 break; /* not sure what happened there */
686 f
= new_fdstruct(newfd
, FD_CONNECTION
);
687 f
->cctx
= new_connection(t
);
688 if (authtype
== HTTPD_AUTH_MAGIC
)
689 check_magic_access(f
);
693 if (FD_ISSET(fds
[i
].fd
, &rfds
)) {
695 * There's data to be read.
700 ret
= read(fds
[i
].fd
, readbuf
, sizeof(readbuf
));
703 * This shouldn't happen in a sensible
704 * HTTP connection, so we abandon the
705 * connection if it does.
713 * If we haven't got an HTTP response
714 * yet, keep processing data in the
715 * hope of acquiring one.
717 fds
[i
].wdata
= got_data
718 (fds
[i
].cctx
, readbuf
, ret
,
719 (authtype
== HTTPD_AUTH_NONE
||
720 fds
[i
].magic_access
), authstring
, &cfg
);
722 fds
[i
].wdatalen
= strlen(fds
[i
].wdata
);
727 * Otherwise, just drop our read data
733 if (FD_ISSET(fds
[i
].fd
, &wfds
) &&
734 fds
[i
].wdatapos
< fds
[i
].wdatalen
) {
736 * The socket is writable, and we have data to
739 int ret
= write(fds
[i
].fd
, fds
[i
].wdata
+ fds
[i
].wdatapos
,
740 fds
[i
].wdatalen
- fds
[i
].wdatapos
);
743 * Shouldn't happen; abandon the connection.
749 fds
[i
].wdatapos
+= ret
;
750 if (fds
[i
].wdatapos
== fds
[i
].wdatalen
) {
751 shutdown(fds
[i
].fd
, SHUT_WR
);