mailinfo.con commit Allow building Git in systems without iconv (b6e56ec)
   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
  16static FILE *cmitmsg, *patchfile;
  17
  18static int keep_subject = 0;
  19static char *metainfo_charset = NULL;
  20static char line[1000];
  21static char date[1000];
  22static char name[1000];
  23static char email[1000];
  24static char subject[1000];
  25
  26static enum  {
  27        TE_DONTCARE, TE_QP, TE_BASE64,
  28} transfer_encoding;
  29static char charset[256];
  30
  31static char multipart_boundary[1000];
  32static int multipart_boundary_len;
  33static int patch_lines = 0;
  34
  35static 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
  45static 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
  75static 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
 144static int handle_date(char *line)
 145{
 146        strcpy(date, line);
 147        return 0;
 148}
 149
 150static 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
 162static 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
 184static 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
 202static 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
 213static 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
 224static int is_multipart_boundary(const char *line)
 225{
 226        return (!memcmp(line, multipart_boundary, multipart_boundary_len));
 227}
 228
 229static 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: */
 242static 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
 274static 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
 310static 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
 327typedef int (*header_fn_t)(char *);
 328struct header_def {
 329        const char *name;
 330        header_fn_t func;
 331        int namelen;
 332};
 333
 334static 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
 352static 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}
 362static 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
 376static 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
 397static 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
 408static 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
 425static 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
 472static 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
 510static 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
 565static 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
 583static 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 */
 612static 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 */
 646static 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 */
 667static 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
 696static 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 */
 729static 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
 753static const char mailinfo_usage[] =
 754        "git-mailinfo [-k] [-u | --encoding=<encoding>] msg patch <mail >info";
 755
 756int 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}