mailinfo.c

   1 /*
   2  * Another stupid program, this one parsing the headers of an
   3  * email to figure out authorship and subject
   4  */
   5 #define _GNU_SOURCE
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <string.h>
   9 #include <ctype.h>
  10 #ifndef NO_ICONV
  11 #include <iconv.h>
  12 #endif
  13 #include "git-compat-util.h"
  14 #include "cache.h"
  15
  16 static FILE *cmitmsg, *patchfile;
  17
  18 static int keep_subject = 0;
  19 static char *metainfo_charset = NULL;
  20 static char line[1000];
  21 static char date[1000];
  22 static char name[1000];
  23 static char email[1000];
  24 static char subject[1000];
  25
  26 static enum  {
  27         TE_DONTCARE, TE_QP, TE_BASE64,
  28 } transfer_encoding;
  29 static char charset[256];
  30
  31 static char multipart_boundary[1000];
  32 static int multipart_boundary_len;
  33 static int patch_lines = 0;
  34
  35 static char *sanity_check(char *name, char *email)
  36 {
  37         int len = strlen(name);
  38         if (len < 3 || len > 60)
  39                 return email;
  40         if (strchr(name, '@') || strchr(name, '<') || strchr(name, '>'))
  41                 return email;
  42         return name;
  43 }
  44
  45 static int bogus_from(char *line)
  46 {
  47         /* John Doe <johndoe> */
  48         char *bra, *ket, *dst, *cp;
  49
  50         /* This is fallback, so do not bother if we already have an
  51          * e-mail address.
  52          */
  53         if (*email)
  54                 return 0;
  55
  56         bra = strchr(line, '<');
  57         if (!bra)
  58                 return 0;
  59         ket = strchr(bra, '>');
  60         if (!ket)
  61                 return 0;
  62
  63         for (dst = email, cp = bra+1; cp < ket; )
  64                 *dst++ = *cp++;
  65         *dst = 0;
  66         for (cp = line; isspace(*cp); cp++)
  67                 ;
  68         for (bra--; isspace(*bra); bra--)
  69                 *bra = 0;
  70         cp = sanity_check(cp, email);
  71         strcpy(name, cp);
  72         return 1;
  73 }
  74
  75 static int handle_from(char *line)
  76 {
  77         char *at = strchr(line, '@');
  78         char *dst;
  79
  80         if (!at)
  81                 return bogus_from(line);
  82
  83         /*
  84          * If we already have one email, don't take any confusing lines
  85          */
  86         if (*email && strchr(at+1, '@'))
  87                 return 0;
  88
  89         /* Pick up the string around '@', possibly delimited with <>
  90          * pair; that is the email part.  White them out while copying.
  91          */
  92         while (at > line) {
  93                 char c = at[-1];
  94                 if (isspace(c))
  95                         break;
  96                 if (c == '<') {
  97                         at[-1] = ' ';
  98                         break;
  99                 }
 100                 at--;
 101         }
 102         dst = email;
 103         for (;;) {
 104                 unsigned char c = *at;
 105                 if (!c || c == '>' || isspace(c)) {
 106                         if (c == '>')
 107                                 *at = ' ';
 108                         break;
 109                 }
 110                 *at++ = ' ';
 111                 *dst++ = c;
 112         }
 113         *dst++ = 0;
 114
 115         /* The remainder is name.  It could be "John Doe <john.doe@xz>"
 116          * or "john.doe@xz (John Doe)", but we have whited out the
 117          * email part, so trim from both ends, possibly removing
 118          * the () pair at the end.
 119          */
 120         at = line + strlen(line);
 121         while (at > line) {
 122                 unsigned char c = *--at;
 123                 if (!isspace(c)) {
 124                         at[(c == ')') ? 0 : 1] = 0;
 125                         break;
 126                 }
 127         }
 128
 129         at = line;
 130         for (;;) {
 131                 unsigned char c = *at;
 132                 if (!c || !isspace(c)) {
 133                         if (c == '(')
 134                                 at++;
 135                         break;
 136                 }
 137                 at++;
 138         }
 139         at = sanity_check(at, email);
 140         strcpy(name, at);
 141         return 1;
 142 }
 143
 144 static int handle_date(char *line)
 145 {
 146         strcpy(date, line);
 147         return 0;
 148 }
 149
 150 static int handle_subject(char *line)
 151 {
 152         strcpy(subject, line);
 153         return 0;
 154 }
 155
 156 /* NOTE NOTE NOTE.  We do not claim we do full MIME.  We just attempt
 157  * to have enough heuristics to grok MIME encoded patches often found
 158  * on our mailing lists.  For example, we do not even treat header lines
 159  * case insensitively.
 160  */
 161
 162 static int slurp_attr(const char *line, const char *name, char *attr)
 163 {
 164         char *ends, *ap = strcasestr(line, name);
 165         size_t sz;
 166
 167         if (!ap) {
 168                 *attr = 0;
 169                 return 0;
 170         }
 171         ap += strlen(name);
 172         if (*ap == '"') {
 173                 ap++;
 174                 ends = "\"";
 175         }
 176         else
 177                 ends = "; \t";
 178         sz = strcspn(ap, ends);
 179         memcpy(attr, ap, sz);
 180         attr[sz] = 0;
 181         return 1;
 182 }
 183
 184 static int handle_subcontent_type(char *line)
 185 {
 186         /* We do not want to mess with boundary.  Note that we do not
 187          * handle nested multipart.
 188          */
 189         if (strcasestr(line, "boundary=")) {
 190                 fprintf(stderr, "Not handling nested multipart message.\n");
 191                 exit(1);
 192         }
 193         slurp_attr(line, "charset=", charset);
 194         if (*charset) {
 195                 int i, c;
 196                 for (i = 0; (c = charset[i]) != 0; i++)
 197                         charset[i] = tolower(c);
 198         }
 199         return 0;
 200 }
 201
 202 static int handle_content_type(char *line)
 203 {
 204         *multipart_boundary = 0;
 205         if (slurp_attr(line, "boundary=", multipart_boundary + 2)) {
 206                 memcpy(multipart_boundary, "--", 2);
 207                 multipart_boundary_len = strlen(multipart_boundary);
 208         }
 209         slurp_attr(line, "charset=", charset);
 210         return 0;
 211 }
 212
 213 static int handle_content_transfer_encoding(char *line)
 214 {
 215         if (strcasestr(line, "base64"))
 216                 transfer_encoding = TE_BASE64;
 217         else if (strcasestr(line, "quoted-printable"))
 218                 transfer_encoding = TE_QP;
 219         else
 220                 transfer_encoding = TE_DONTCARE;
 221         return 0;
 222 }
 223
 224 static int is_multipart_boundary(const char *line)
 225 {
 226         return (!memcmp(line, multipart_boundary, multipart_boundary_len));
 227 }
 228
 229 static int eatspace(char *line)
 230 {
 231         int len = strlen(line);
 232         while (len > 0 && isspace(line[len-1]))
 233                 line[--len] = 0;
 234         return len;
 235 }
 236
 237 #define SEEN_FROM 01
 238 #define SEEN_DATE 02
 239 #define SEEN_SUBJECT 04
 240
 241 /* First lines of body can have From:, Date:, and Subject: */
 242 static int handle_inbody_header(int *seen, char *line)
 243 {
 244         if (!memcmp("From:", line, 5) && isspace(line[5])) {
 245                 if (!(*seen & SEEN_FROM) && handle_from(line+6)) {
 246                         *seen |= SEEN_FROM;
 247                         return 1;
 248                 }
 249         }
 250         if (!memcmp("Date:", line, 5) && isspace(line[5])) {
 251                 if (!(*seen & SEEN_DATE)) {
 252                         handle_date(line+6);
 253                         *seen |= SEEN_DATE;
 254                         return 1;
 255                 }
 256         }
 257         if (!memcmp("Subject:", line, 8) && isspace(line[8])) {
 258                 if (!(*seen & SEEN_SUBJECT)) {
 259                         handle_subject(line+9);
 260                         *seen |= SEEN_SUBJECT;
 261                         return 1;
 262                 }
 263         }
 264         if (!memcmp("[PATCH]", line, 7) && isspace(line[7])) {
 265                 if (!(*seen & SEEN_SUBJECT)) {
 266                         handle_subject(line);
 267                         *seen |= SEEN_SUBJECT;
 268                         return 1;
 269                 }
 270         }
 271         return 0;
 272 }
 273
 274 static char *cleanup_subject(char *subject)
 275 {
 276         if (keep_subject)
 277                 return subject;
 278         for (;;) {
 279                 char *p;
 280                 int len, remove;
 281                 switch (*subject) {
 282                 case 'r': case 'R':
 283                         if (!memcmp("e:", subject+1, 2)) {
 284                                 subject +=3;
 285                                 continue;
 286                         }
 287                         break;
 288                 case ' ': case '\t': case ':':
 289                         subject++;
 290                         continue;
 291
 292                 case '[':
 293                         p = strchr(subject, ']');
 294                         if (!p) {
 295                                 subject++;
 296                                 continue;
 297                         }
 298                         len = strlen(p);
 299                         remove = p - subject;
 300                         if (remove <= len *2) {
 301                                 subject = p+1;
 302                                 continue;
 303                         }
 304                         break;
 305                 }
 306                 return subject;
 307         }
 308 }
 309
 310 static void cleanup_space(char *buf)
 311 {
 312         unsigned char c;
 313         while ((c = *buf) != 0) {
 314                 buf++;
 315                 if (isspace(c)) {
 316                         buf[-1] = ' ';
 317                         c = *buf;
 318                         while (isspace(c)) {
 319                                 int len = strlen(buf);
 320                                 memmove(buf, buf+1, len);
 321                                 c = *buf;
 322                         }
 323                 }
 324         }
 325 }
 326
 327 typedef int (*header_fn_t)(char *);
 328 struct header_def {
 329         const char *name;
 330         header_fn_t func;
 331         int namelen;
 332 };
 333
 334 static void check_header(char *line, int len, struct header_def *header)
 335 {
 336         int i;
 337
 338         if (header[0].namelen <= 0) {
 339                 for (i = 0; header[i].name; i++)
 340                         header[i].namelen = strlen(header[i].name);
 341         }
 342         for (i = 0; header[i].name; i++) {
 343                 int len = header[i].namelen;
 344                 if (!strncasecmp(line, header[i].name, len) &&
 345                     line[len] == ':' && isspace(line[len + 1])) {
 346                         header[i].func(line + len + 2);
 347                         break;
 348                 }
 349         }
 350 }
 351
 352 static void check_subheader_line(char *line, int len)
 353 {
 354         static struct header_def header[] = {
 355                 { "Content-Type", handle_subcontent_type },
 356                 { "Content-Transfer-Encoding",
 357                   handle_content_transfer_encoding },
 358                 { NULL },
 359         };
 360         check_header(line, len, header);
 361 }
 362 static void check_header_line(char *line, int len)
 363 {
 364         static struct header_def header[] = {
 365                 { "From", handle_from },
 366                 { "Date", handle_date },
 367                 { "Subject", handle_subject },
 368                 { "Content-Type", handle_content_type },
 369                 { "Content-Transfer-Encoding",
 370                   handle_content_transfer_encoding },
 371                 { NULL },
 372         };
 373         check_header(line, len, header);
 374 }
 375
 376 static int read_one_header_line(char *line, int sz, FILE *in)
 377 {
 378         int ofs = 0;
 379         while (ofs < sz) {
 380                 int peek, len;
 381                 if (fgets(line + ofs, sz - ofs, in) == NULL)
 382                         return ofs;
 383                 len = eatspace(line + ofs);
 384                 if (len == 0)
 385                         return ofs;
 386                 peek = fgetc(in); ungetc(peek, in);
 387                 if (peek == ' ' || peek == '\t') {
 388                         /* Yuck, 2822 header "folding" */
 389                         ofs += len;
 390                         continue;
 391                 }
 392                 return ofs + len;
 393         }
 394         return ofs;
 395 }
 396
 397 static unsigned hexval(int c)
 398 {
 399         if (c >= '0' && c <= '9')
 400                 return c - '0';
 401         if (c >= 'a' && c <= 'f')
 402                 return c - 'a' + 10;
 403         if (c >= 'A' && c <= 'F')
 404                 return c - 'A' + 10;
 405         return ~0;
 406 }
 407
 408 static int decode_q_segment(char *in, char *ot, char *ep)
 409 {
 410         int c;
 411         while ((c = *in++) != 0 && (in <= ep)) {
 412                 if (c == '=') {
 413                         int d = *in++;
 414                         if (d == '\n' || !d)
 415                                 break; /* drop trailing newline */
 416                         *ot++ = ((hexval(d) << 4) | hexval(*in++));
 417                 }
 418                 else
 419                         *ot++ = c;
 420         }
 421         *ot = 0;
 422         return 0;
 423 }
 424
 425 static int decode_b_segment(char *in, char *ot, char *ep)
 426 {
 427         /* Decode in..ep, possibly in-place to ot */
 428         int c, pos = 0, acc = 0;
 429
 430         while ((c = *in++) != 0 && (in <= ep)) {
 431                 if (c == '+')
 432                         c = 62;
 433                 else if (c == '/')
 434                         c = 63;
 435                 else if ('A' <= c && c <= 'Z')
 436                         c -= 'A';
 437                 else if ('a' <= c && c <= 'z')
 438                         c -= 'a' - 26;
 439                 else if ('0' <= c && c <= '9')
 440                         c -= '0' - 52;
 441                 else if (c == '=') {
 442                         /* padding is almost like (c == 0), except we do
 443                          * not output NUL resulting only from it;
 444                          * for now we just trust the data.
 445                          */
 446                         c = 0;
 447                 }
 448                 else
 449                         continue; /* garbage */
 450                 switch (pos++) {
 451                 case 0:
 452                         acc = (c << 2);
 453                         break;
 454                 case 1:
 455                         *ot++ = (acc | (c >> 4));
 456                         acc = (c & 15) << 4;
 457                         break;
 458                 case 2:
 459                         *ot++ = (acc | (c >> 2));
 460                         acc = (c & 3) << 6;
 461                         break;
 462                 case 3:
 463                         *ot++ = (acc | c);
 464                         acc = pos = 0;
 465                         break;
 466                 }
 467         }
 468         *ot = 0;
 469         return 0;
 470 }
 471
 472 static void convert_to_utf8(char *line, char *charset)
 473 {
 474 #ifndef NO_ICONV
 475         char *in, *out;
 476         size_t insize, outsize, nrc;
 477         char outbuf[4096]; /* cheat */
 478         static char latin_one[] = "latin1";
 479         char *input_charset = *charset ? charset : latin_one;
 480         iconv_t conv = iconv_open(metainfo_charset, input_charset);
 481
 482         if (conv == (iconv_t) -1) {
 483                 static int warned_latin1_once = 0;
 484                 if (input_charset != latin_one) {
 485                         fprintf(stderr, "cannot convert from %s to %s\n",
 486                                 input_charset, metainfo_charset);
 487                         *charset = 0;
 488                 }
 489                 else if (!warned_latin1_once) {
 490                         warned_latin1_once = 1;
 491                         fprintf(stderr, "tried to convert from %s to %s, "
 492                                 "but your iconv does not work with it.\n",
 493                                 input_charset, metainfo_charset);
 494                 }
 495                 return;
 496         }
 497         in = line;
 498         insize = strlen(in);
 499         out = outbuf;
 500         outsize = sizeof(outbuf);
 501         nrc = iconv(conv, &in, &insize, &out, &outsize);
 502         iconv_close(conv);
 503         if (nrc == (size_t) -1)
 504                 return;
 505         *out = 0;
 506         strcpy(line, outbuf);
 507 #endif
 508 }
 509
 510 static void decode_header_bq(char *it)
 511 {
 512         char *in, *out, *ep, *cp, *sp;
 513         char outbuf[1000];
 514
 515         in = it;
 516         out = outbuf;
 517         while ((ep = strstr(in, "=?")) != NULL) {
 518                 int sz, encoding;
 519                 char charset_q[256], piecebuf[256];
 520                 if (in != ep) {
 521                         sz = ep - in;
 522                         memcpy(out, in, sz);
 523                         out += sz;
 524                         in += sz;
 525                 }
 526                 /* E.g.
 527                  * ep : "=?iso-2022-jp?B?GyR...?= foo"
 528                  * ep : "=?ISO-8859-1?Q?Foo=FCbar?= baz"
 529                  */
 530                 ep += 2;
 531                 cp = strchr(ep, '?');
 532                 if (!cp)
 533                         return; /* no munging */
 534                 for (sp = ep; sp < cp; sp++)
 535                         charset_q[sp - ep] = tolower(*sp);
 536                 charset_q[cp - ep] = 0;
 537                 encoding = cp[1];
 538                 if (!encoding || cp[2] != '?')
 539                         return; /* no munging */
 540                 ep = strstr(cp + 3, "?=");
 541                 if (!ep)
 542                         return; /* no munging */
 543                 switch (tolower(encoding)) {
 544                 default:
 545                         return; /* no munging */
 546                 case 'b':
 547                         sz = decode_b_segment(cp + 3, piecebuf, ep);
 548                         break;
 549                 case 'q':
 550                         sz = decode_q_segment(cp + 3, piecebuf, ep);
 551                         break;
 552                 }
 553                 if (sz < 0)
 554                         return;
 555                 if (metainfo_charset)
 556                         convert_to_utf8(piecebuf, charset_q);
 557                 strcpy(out, piecebuf);
 558                 out += strlen(out);
 559                 in = ep + 2;
 560         }
 561         strcpy(out, in);
 562         strcpy(it, outbuf);
 563 }
 564
 565 static void decode_transfer_encoding(char *line)
 566 {
 567         char *ep;
 568
 569         switch (transfer_encoding) {
 570         case TE_QP:
 571                 ep = line + strlen(line);
 572                 decode_q_segment(line, line, ep);
 573                 break;
 574         case TE_BASE64:
 575                 ep = line + strlen(line);
 576                 decode_b_segment(line, line, ep);
 577                 break;
 578         case TE_DONTCARE:
 579                 break;
 580         }
 581 }
 582
 583 static void handle_info(void)
 584 {
 585         char *sub;
 586         static int done_info = 0;
 587
 588         if (done_info)
 589                 return;
 590
 591         done_info = 1;
 592         sub = cleanup_subject(subject);
 593         cleanup_space(name);
 594         cleanup_space(date);
 595         cleanup_space(email);
 596         cleanup_space(sub);
 597
 598         /* Unwrap inline B and Q encoding, and optionally
 599          * normalize the meta information to utf8.
 600          */
 601         decode_header_bq(name);
 602         decode_header_bq(date);
 603         decode_header_bq(email);
 604         decode_header_bq(sub);
 605         printf("Author: %s\nEmail: %s\nSubject: %s\nDate: %s\n\n",
 606                name, email, sub, date);
 607 }
 608
 609 /* We are inside message body and have read line[] already.
 610  * Spit out the commit log.
 611  */
 612 static int handle_commit_msg(void)
 613 {
 614         if (!cmitmsg)
 615                 return 0;
 616         do {
 617                 if (!memcmp("diff -", line, 6) ||
 618                     !memcmp("---", line, 3) ||
 619                     !memcmp("Index: ", line, 7))
 620                         break;
 621                 if ((multipart_boundary[0] && is_multipart_boundary(line))) {
 622                         /* We come here when the first part had only
 623                          * the commit message without any patch.  We
 624                          * pretend we have not seen this line yet, and
 625                          * go back to the loop.
 626                          */
 627                         return 1;
 628                 }
 629
 630                 /* Unwrap transfer encoding and optionally
 631                  * normalize the log message to UTF-8.
 632                  */
 633                 decode_transfer_encoding(line);
 634                 if (metainfo_charset)
 635                         convert_to_utf8(line, charset);
 636                 fputs(line, cmitmsg);
 637         } while (fgets(line, sizeof(line), stdin) != NULL);
 638         fclose(cmitmsg);
 639         cmitmsg = NULL;
 640         return 0;
 641 }
 642
 643 /* We have done the commit message and have the first
 644  * line of the patch in line[].
 645  */
 646 static void handle_patch(void)
 647 {
 648         do {
 649                 if (multipart_boundary[0] && is_multipart_boundary(line))
 650                         break;
 651                 /* Only unwrap transfer encoding but otherwise do not
 652                  * do anything.  We do *NOT* want UTF-8 conversion
 653                  * here; we are dealing with the user payload.
 654                  */
 655                 decode_transfer_encoding(line);
 656                 fputs(line, patchfile);
 657                 patch_lines++;
 658         } while (fgets(line, sizeof(line), stdin) != NULL);
 659 }
 660
 661 /* multipart boundary and transfer encoding are set up for us, and we
 662  * are at the end of the sub header.  do equivalent of handle_body up
 663  * to the next boundary without closing patchfile --- we will expect
 664  * that the first part to contain commit message and a patch, and
 665  * handle other parts as pure patches.
 666  */
 667 static int handle_multipart_one_part(void)
 668 {
 669         int seen = 0;
 670         int n = 0;
 671         int len;
 672
 673         while (fgets(line, sizeof(line), stdin) != NULL) {
 674         again:
 675                 len = eatspace(line);
 676                 n++;
 677                 if (!len)
 678                         continue;
 679                 if (is_multipart_boundary(line))
 680                         break;
 681                 if (0 <= seen && handle_inbody_header(&seen, line))
 682                         continue;
 683                 seen = -1; /* no more inbody headers */
 684                 line[len] = '\n';
 685                 handle_info();
 686                 if (handle_commit_msg())
 687                         goto again;
 688                 handle_patch();
 689                 break;
 690         }
 691         if (n == 0)
 692                 return -1;
 693         return 0;
 694 }
 695
 696 static void handle_multipart_body(void)
 697 {
 698         int part_num = 0;
 699
 700         /* Skip up to the first boundary */
 701         while (fgets(line, sizeof(line), stdin) != NULL)
 702                 if (is_multipart_boundary(line)) {
 703                         part_num = 1;
 704                         break;
 705                 }
 706         if (!part_num)
 707                 return;
 708         /* We are on boundary line.  Start slurping the subhead. */
 709         while (1) {
 710                 int len = read_one_header_line(line, sizeof(line), stdin);
 711                 if (!len) {
 712                         if (handle_multipart_one_part() < 0)
 713                                 return;
 714                         /* Reset per part headers */
 715                         transfer_encoding = TE_DONTCARE;
 716                         charset[0] = 0;
 717                 }
 718                 else
 719                         check_subheader_line(line, len);
 720         }
 721         fclose(patchfile);
 722         if (!patch_lines) {
 723                 fprintf(stderr, "No patch found\n");
 724                 exit(1);
 725         }
 726 }
 727
 728 /* Non multipart message */
 729 static void handle_body(void)
 730 {
 731         int seen = 0;
 732
 733         while (fgets(line, sizeof(line), stdin) != NULL) {
 734                 int len = eatspace(line);
 735                 if (!len)
 736                         continue;
 737                 if (0 <= seen && handle_inbody_header(&seen, line))
 738                         continue;
 739                 seen = -1; /* no more inbody headers */
 740                 line[len] = '\n';
 741                 handle_info();
 742                 handle_commit_msg();
 743                 handle_patch();
 744                 break;
 745         }
 746         fclose(patchfile);
 747         if (!patch_lines) {
 748                 fprintf(stderr, "No patch found\n");
 749                 exit(1);
 750         }
 751 }
 752
 753 static const char mailinfo_usage[] =
 754         "git-mailinfo [-k] [-u | --encoding=<encoding>] msg patch <mail >info";
 755
 756 int main(int argc, char **argv)
 757 {
 758         /* NEEDSWORK: might want to do the optional .git/ directory
 759          * discovery
 760          */
 761         git_config(git_default_config);
 762
 763         while (1 < argc && argv[1][0] == '-') {
 764                 if (!strcmp(argv[1], "-k"))
 765                         keep_subject = 1;
 766                 else if (!strcmp(argv[1], "-u"))
 767                         metainfo_charset = git_commit_encoding;
 768                 else if (!strncmp(argv[1], "--encoding=", 11))
 769                         metainfo_charset = argv[1] + 11;
 770                 else
 771                         usage(mailinfo_usage);
 772                 argc--; argv++;
 773         }
 774
 775         if (argc != 3)
 776                 usage(mailinfo_usage);
 777         cmitmsg = fopen(argv[1], "w");
 778         if (!cmitmsg) {
 779                 perror(argv[1]);
 780                 exit(1);
 781         }
 782         patchfile = fopen(argv[2], "w");
 783         if (!patchfile) {
 784                 perror(argv[2]);
 785                 exit(1);
 786         }
 787         while (1) {
 788                 int len = read_one_header_line(line, sizeof(line), stdin);
 789                 if (!len) {
 790                         if (multipart_boundary[0])
 791                                 handle_multipart_body();
 792                         else
 793                                 handle_body();
 794                         break;
 795                 }
 796                 check_header_line(line, len);
 797         }
 798         return 0;
 799 }