ref: 02a26802ffbd64ebf993119e1599920ffee01ef0
dir: /sys/src/cmd/ip/httpd/sendfd.c/
#include <u.h> #include <libc.h> #include <auth.h> #include "httpd.h" #include "httpsrv.h" static void printtype(Hio *hout, HContent *type, HContent *enc); /* * these should be done better; see the reponse codes in /lib/rfc/rfc2616 for * more info on what should be included. */ #define UNAUTHED "You are not authorized to see this area.\n" #define NOCONTENT "No acceptable type of data is available.\n" #define NOENCODE "No acceptable encoding of the contents is available.\n" #define UNMATCHED "The entity requested does not match the existing entity.\n" #define BADRANGE "No bytes are avaible for the range you requested.\n" /* * fd references a file which has been authorized & checked for relocations. * send back the headers & its contents. * includes checks for conditional requests & ranges. */ int sendfd(HConnect *c, int fd, Dir *dir, HContent *type, HContent *enc) { Qid qid; HRange *r; HContents conts; Hio *hout; char *boundary, etag[32]; long mtime; ulong tr; int n, nw, multir, ok; vlong wrote, length; hout = &c->hout; length = dir->length; mtime = dir->mtime; qid = dir->qid; free(dir); /* * figure out the type of file and send headers */ n = -1; r = nil; multir = 0; boundary = nil; if(c->req.vermaj){ if(type == nil && enc == nil){ conts = uriclass(c, c->req.uri); type = conts.type; enc = conts.encoding; if(type == nil && enc == nil){ n = read(fd, c->xferbuf, HBufSize-1); if(n > 0){ c->xferbuf[n] = '\0'; conts = dataclass(c, c->xferbuf, n); type = conts.type; enc = conts.encoding; } } } if(type == nil) type = hmkcontent(c, "application", "octet-stream", nil); snprint(etag, sizeof(etag), "\"%lluxv%lux\"", qid.path, qid.vers); ok = checkreq(c, type, enc, mtime, etag); if(ok <= 0){ close(fd); return ok; } /* * check for if-range requests */ if(c->head.range == nil || c->head.ifrangeetag != nil && !etagmatch(1, c->head.ifrangeetag, etag) || c->head.ifrangedate != 0 && c->head.ifrangedate != mtime){ c->head.range = nil; c->head.ifrangeetag = nil; c->head.ifrangedate = 0; } if(c->head.range != nil){ c->head.range = fixrange(c->head.range, length); if(c->head.range == nil){ if(c->head.ifrangeetag == nil && c->head.ifrangedate == 0){ hprint(hout, "%s 416 Request range not satisfiable\r\n", hversion); hprint(hout, "Date: %D\r\n", time(nil)); hprint(hout, "Server: Plan9\r\n"); hprint(hout, "Content-Range: bytes */%lld\r\n", length); hprint(hout, "Content-Length: %d\r\n", STRLEN(BADRANGE)); hprint(hout, "Content-Type: text/html\r\n"); if(c->head.closeit) hprint(hout, "Connection: close\r\n"); else if(!http11(c)) hprint(hout, "Connection: Keep-Alive\r\n"); hprint(hout, "\r\n"); if(strcmp(c->req.meth, "HEAD") != 0) hprint(hout, "%s", BADRANGE); hflush(hout); writelog(c, "Reply: 416 Request range not satisfiable\n"); close(fd); return 1; } c->head.ifrangeetag = nil; c->head.ifrangedate = 0; } } if(c->head.range == nil) hprint(hout, "%s 200 OK\r\n", hversion); else hprint(hout, "%s 206 Partial Content\r\n", hversion); hprint(hout, "Server: Plan9\r\n"); hprint(hout, "Date: %D\r\n", time(nil)); hprint(hout, "ETag: %s\r\n", etag); /* * can't send some entity headers if partially responding * to an if-range: etag request */ r = c->head.range; if(r == nil) hprint(hout, "Content-Length: %lld\r\n", length); else if(r->next == nil){ hprint(hout, "Content-Range: bytes %ld-%ld/%lld\r\n", r->start, r->stop, length); hprint(hout, "Content-Length: %ld\r\n", 1 + r->stop - r->start); }else{ multir = 1; boundary = hmkmimeboundary(c); hprint(hout, "Content-Type: multipart/byteranges; boundary=%s\r\n", boundary); } if(c->head.ifrangeetag == nil){ hprint(hout, "Last-Modified: %D\r\n", mtime); if(!multir) printtype(hout, type, enc); if(c->head.fresh_thresh) hintprint(c, hout, c->req.uri, c->head.fresh_thresh, c->head.fresh_have); } if(c->head.closeit) hprint(hout, "Connection: close\r\n"); else if(!http11(c)) hprint(hout, "Connection: Keep-Alive\r\n"); hprint(hout, "\r\n"); } if(strcmp(c->req.meth, "HEAD") == 0){ if(c->head.range == nil) writelog(c, "Reply: 200 file 0\n"); else writelog(c, "Reply: 206 file 0\n"); hflush(hout); close(fd); return 1; } /* * send the file if it's a normal file */ if(r == nil){ hflush(hout); wrote = 0; if(n > 0) wrote = write(hout->fd, c->xferbuf, n); if(n <= 0 || wrote == n){ while((n = read(fd, c->xferbuf, HBufSize)) > 0){ nw = write(hout->fd, c->xferbuf, n); if(nw != n){ if(nw > 0) wrote += nw; break; } wrote += nw; } } writelog(c, "Reply: 200 file %lld %lld\n", length, wrote); close(fd); if(length == wrote) return 1; return -1; } /* * for multipart/byterange messages, * it is not ok for the boundary string to appear within a message part. * however, it probably doesn't matter, since there are lengths for every part. */ wrote = 0; ok = 1; for(; r != nil; r = r->next){ if(multir){ hprint(hout, "\r\n--%s\r\n", boundary); printtype(hout, type, enc); hprint(hout, "Content-Range: bytes %ld-%ld/%lld\r\n", r->start, r->stop, length); hprint(hout, "Content-Length: %ld\r\n", 1 + r->stop - r->start); hprint(hout, "\r\n"); } hflush(hout); if(seek(fd, r->start, 0) != r->start){ ok = -1; break; } for(tr = 1 + r->stop - r->start; tr; tr -= n){ n = tr; if(n > HBufSize) n = HBufSize; if(read(fd, c->xferbuf, n) != n){ ok = -1; goto breakout; } nw = write(hout->fd, c->xferbuf, n); if(nw != n){ if(nw > 0) wrote += nw; ok = -1; goto breakout; } wrote += nw; } } breakout:; if(r == nil){ if(multir){ hprint(hout, "--%s--\r\n", boundary); hflush(hout); } writelog(c, "Reply: 206 partial content %lld %lld\n", length, wrote); }else writelog(c, "Reply: 206 partial content, early termination %lld %lld\n", length, wrote); close(fd); return ok; } static void printtype(Hio *hout, HContent *type, HContent *enc) { hprint(hout, "Content-Type: %s/%s", type->generic, type->specific); /* if(cistrcmp(type->generic, "text") == 0) hprint(hout, ";charset=utf-8"); */ hprint(hout, "\r\n"); if(enc != nil) hprint(hout, "Content-Encoding: %s\r\n", enc->generic); } int etagmatch(int strong, HETag *tags, char *e) { char *s, *t; for(; tags != nil; tags = tags->next){ if(strong && tags->weak) continue; s = tags->etag; if(s[0] == '*' && s[1] == '\0') return 1; t = e + 1; while(*t != '"'){ if(*s != *t) break; s++; t++; } if(*s == '\0' && *t == '"') return 1; } return 0; } static char * acceptcont(char *s, char *e, HContent *ok, char *which) { char *sep; if(ok == nil) return seprint(s, e, "Your browser accepts any %s.<br>\n", which); s = seprint(s, e, "Your browser accepts %s: ", which); sep = ""; for(; ok != nil; ok = ok->next){ if(ok->specific) s = seprint(s, e, "%s%s/%s", sep, ok->generic, ok->specific); else s = seprint(s, e, "%s%s", sep, ok->generic); sep = ", "; } return seprint(s, e, ".<br>\n"); } /* * send back a nice error message if the content is unacceptable * to get this message in ie, go to tools, internet options, advanced, * and turn off Show Friendly HTTP Error Messages under the Browsing category */ static int notaccept(HConnect *c, HContent *type, HContent *enc, char *which) { Hio *hout; char *s, *e; hout = &c->hout; e = &c->xferbuf[HBufSize]; s = c->xferbuf; s = seprint(s, e, "<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.0 Transitional//EN\">\n"); s = seprint(s, e, "<html>\n<title>Unacceptable %s</title>\n<body>\n", which); s = seprint(s, e, "Your browser will not accept this data, %H, because of its %s.<br>\n", c->req.uri, which); s = seprint(s, e, "Its Content-Type is %s/%s", type->generic, type->specific); if(enc != nil) s = seprint(s, e, ", and Content-Encoding is %s", enc->generic); s = seprint(s, e, ".<br>\n\n"); s = acceptcont(s, e, c->head.oktype, "Content-Type"); s = acceptcont(s, e, c->head.okencode, "Content-Encoding"); s = seprint(s, e, "</body>\n</html>\n"); hprint(hout, "%s 406 Not Acceptable\r\n", hversion); hprint(hout, "Server: Plan9\r\n"); hprint(hout, "Date: %D\r\n", time(nil)); hprint(hout, "Content-Type: text/html\r\n"); hprint(hout, "Content-Length: %zud\r\n", s - c->xferbuf); if(c->head.closeit) hprint(hout, "Connection: close\r\n"); else if(!http11(c)) hprint(hout, "Connection: Keep-Alive\r\n"); hprint(hout, "\r\n"); if(strcmp(c->req.meth, "HEAD") != 0) hwrite(hout, c->xferbuf, s - c->xferbuf); writelog(c, "Reply: 406 Not Acceptable\nReason: %s\n", which); return hflush(hout); } /* * check time and entity tag conditions. */ int checkreq(HConnect *c, HContent *type, HContent *enc, long mtime, char *etag) { Hio *hout; int m; hout = &c->hout; if(c->req.vermaj >= 1 && c->req.vermin >= 1 && !hcheckcontent(type, c->head.oktype, "Content-Type", 0)) return notaccept(c, type, enc, "Content-Type"); if(c->req.vermaj >= 1 && c->req.vermin >= 1 && !hcheckcontent(enc, c->head.okencode, "Content-Encoding", 0)) return notaccept(c, type, enc, "Content-Encoding"); /* * can use weak match only with get or head; * this always uses strong matches */ m = etagmatch(1, c->head.ifnomatch, etag); if(m && strcmp(c->req.meth, "GET") != 0 && strcmp(c->req.meth, "HEAD") != 0 || c->head.ifunmodsince && c->head.ifunmodsince < mtime || c->head.ifmatch != nil && !etagmatch(1, c->head.ifmatch, etag)){ hprint(hout, "%s 412 Precondition Failed\r\n", hversion); hprint(hout, "Server: Plan9\r\n"); hprint(hout, "Date: %D\r\n", time(nil)); hprint(hout, "Content-Type: text/html\r\n"); hprint(hout, "Content-Length: %d\r\n", STRLEN(UNMATCHED)); if(c->head.closeit) hprint(hout, "Connection: close\r\n"); else if(!http11(c)) hprint(hout, "Connection: Keep-Alive\r\n"); hprint(hout, "\r\n"); if(strcmp(c->req.meth, "HEAD") != 0) hprint(hout, "%s", UNMATCHED); writelog(c, "Reply: 412 Precondition Failed\n"); return hflush(hout); } if(c->head.ifmodsince >= mtime && (m || c->head.ifnomatch == nil)){ /* * can only send back Date, ETag, Content-Location, * Expires, Cache-Control, and Vary entity-headers */ hprint(hout, "%s 304 Not Modified\r\n", hversion); hprint(hout, "Server: Plan9\r\n"); hprint(hout, "Date: %D\r\n", time(nil)); hprint(hout, "ETag: %s\r\n", etag); if(c->head.closeit) hprint(hout, "Connection: close\r\n"); else if(!http11(c)) hprint(hout, "Connection: Keep-Alive\r\n"); hprint(hout, "\r\n"); writelog(c, "Reply: 304 Not Modified\n"); return hflush(hout); } return 1; } /* * length is the actual length of the entity requested. * discard any range requests which are invalid, * ie start after the end, or have stop before start. * rewrite suffix requests */ HRange* fixrange(HRange *h, long length) { HRange *r, *rr; if(length == 0) return nil; /* * rewrite each range to reflect the actual length of the file * toss out any invalid ranges */ rr = nil; for(r = h; r != nil; r = r->next){ if(r->suffix){ /* * for suffix, r->stop is a byte *length* * not the byte *offset* of last byte! */ r->start = length - r->stop; if(r->start >= length) r->start = 0; r->stop = length - 1; r->suffix = 0; } if(r->stop >= length) r->stop = length - 1; if(r->start > r->stop){ if(rr == nil) h = r->next; else rr->next = r->next; }else rr = r; } /* * merge consecutive overlapping or abutting ranges * * not clear from rfc2616 how much merging needs to be done. * this code merges only if a range is adjacent to a later starting, * over overlapping or abutting range. this allows a client * to request wanted data first, followed by other data. * this may be useful then fetching part of a page, then the adjacent regions. */ if(h == nil) return h; r = h; for(;;){ rr = r->next; if(rr == nil) break; if(r->start <= rr->start && r->stop + 1 >= rr->start){ if(r->stop < rr->stop) r->stop = rr->stop; r->next = rr->next; }else r = rr; } return h; }