ident.con commit Merge branch 'mm/push-social-engineering-attack-doc' (5f52e70)
   1/*
   2 * ident.c
   3 *
   4 * create git identifier lines of the form "name <email> date"
   5 *
   6 * Copyright (C) 2005 Linus Torvalds
   7 */
   8#include "cache.h"
   9
  10static struct strbuf git_default_name = STRBUF_INIT;
  11static struct strbuf git_default_email = STRBUF_INIT;
  12static struct strbuf git_default_date = STRBUF_INIT;
  13static int default_email_is_bogus;
  14static int default_name_is_bogus;
  15
  16static int ident_use_config_only;
  17
  18#define IDENT_NAME_GIVEN 01
  19#define IDENT_MAIL_GIVEN 02
  20#define IDENT_ALL_GIVEN (IDENT_NAME_GIVEN|IDENT_MAIL_GIVEN)
  21static int committer_ident_explicitly_given;
  22static int author_ident_explicitly_given;
  23static int ident_config_given;
  24
  25#ifdef NO_GECOS_IN_PWENT
  26#define get_gecos(ignored) "&"
  27#else
  28#define get_gecos(struct_passwd) ((struct_passwd)->pw_gecos)
  29#endif
  30
  31static struct passwd *xgetpwuid_self(int *is_bogus)
  32{
  33        struct passwd *pw;
  34
  35        errno = 0;
  36        pw = getpwuid(getuid());
  37        if (!pw) {
  38                static struct passwd fallback;
  39                fallback.pw_name = "unknown";
  40#ifndef NO_GECOS_IN_PWENT
  41                fallback.pw_gecos = "Unknown";
  42#endif
  43                pw = &fallback;
  44                if (is_bogus)
  45                        *is_bogus = 1;
  46        }
  47        return pw;
  48}
  49
  50static void copy_gecos(const struct passwd *w, struct strbuf *name)
  51{
  52        char *src;
  53
  54        /* Traditionally GECOS field had office phone numbers etc, separated
  55         * with commas.  Also & stands for capitalized form of the login name.
  56         */
  57
  58        for (src = get_gecos(w); *src && *src != ','; src++) {
  59                int ch = *src;
  60                if (ch != '&')
  61                        strbuf_addch(name, ch);
  62                else {
  63                        /* Sorry, Mr. McDonald... */
  64                        strbuf_addch(name, toupper(*w->pw_name));
  65                        strbuf_addstr(name, w->pw_name + 1);
  66                }
  67        }
  68}
  69
  70static int add_mailname_host(struct strbuf *buf)
  71{
  72        FILE *mailname;
  73        struct strbuf mailnamebuf = STRBUF_INIT;
  74
  75        mailname = fopen("/etc/mailname", "r");
  76        if (!mailname) {
  77                if (errno != ENOENT)
  78                        warning_errno("cannot open /etc/mailname");
  79                return -1;
  80        }
  81        if (strbuf_getline(&mailnamebuf, mailname) == EOF) {
  82                if (ferror(mailname))
  83                        warning_errno("cannot read /etc/mailname");
  84                strbuf_release(&mailnamebuf);
  85                fclose(mailname);
  86                return -1;
  87        }
  88        /* success! */
  89        strbuf_addbuf(buf, &mailnamebuf);
  90        strbuf_release(&mailnamebuf);
  91        fclose(mailname);
  92        return 0;
  93}
  94
  95static int canonical_name(const char *host, struct strbuf *out)
  96{
  97        int status = -1;
  98
  99#ifndef NO_IPV6
 100        struct addrinfo hints, *ai;
 101        memset (&hints, '\0', sizeof (hints));
 102        hints.ai_flags = AI_CANONNAME;
 103        if (!getaddrinfo(host, NULL, &hints, &ai)) {
 104                if (ai && ai->ai_canonname && strchr(ai->ai_canonname, '.')) {
 105                        strbuf_addstr(out, ai->ai_canonname);
 106                        status = 0;
 107                }
 108                freeaddrinfo(ai);
 109        }
 110#else
 111        struct hostent *he = gethostbyname(host);
 112        if (he && strchr(he->h_name, '.')) {
 113                strbuf_addstr(out, he->h_name);
 114                status = 0;
 115        }
 116#endif /* NO_IPV6 */
 117
 118        return status;
 119}
 120
 121static void add_domainname(struct strbuf *out, int *is_bogus)
 122{
 123        char buf[1024];
 124
 125        if (gethostname(buf, sizeof(buf))) {
 126                warning_errno("cannot get host name");
 127                strbuf_addstr(out, "(none)");
 128                *is_bogus = 1;
 129                return;
 130        }
 131        if (strchr(buf, '.'))
 132                strbuf_addstr(out, buf);
 133        else if (canonical_name(buf, out) < 0) {
 134                strbuf_addf(out, "%s.(none)", buf);
 135                *is_bogus = 1;
 136        }
 137}
 138
 139static void copy_email(const struct passwd *pw, struct strbuf *email,
 140                       int *is_bogus)
 141{
 142        /*
 143         * Make up a fake email address
 144         * (name + '@' + hostname [+ '.' + domainname])
 145         */
 146        strbuf_addstr(email, pw->pw_name);
 147        strbuf_addch(email, '@');
 148
 149        if (!add_mailname_host(email))
 150                return; /* read from "/etc/mailname" (Debian) */
 151        add_domainname(email, is_bogus);
 152}
 153
 154const char *ident_default_name(void)
 155{
 156        if (!git_default_name.len) {
 157                copy_gecos(xgetpwuid_self(&default_name_is_bogus), &git_default_name);
 158                strbuf_trim(&git_default_name);
 159        }
 160        return git_default_name.buf;
 161}
 162
 163const char *ident_default_email(void)
 164{
 165        if (!git_default_email.len) {
 166                const char *email = getenv("EMAIL");
 167
 168                if (email && email[0]) {
 169                        strbuf_addstr(&git_default_email, email);
 170                        committer_ident_explicitly_given |= IDENT_MAIL_GIVEN;
 171                        author_ident_explicitly_given |= IDENT_MAIL_GIVEN;
 172                } else
 173                        copy_email(xgetpwuid_self(&default_email_is_bogus),
 174                                   &git_default_email, &default_email_is_bogus);
 175                strbuf_trim(&git_default_email);
 176        }
 177        return git_default_email.buf;
 178}
 179
 180static const char *ident_default_date(void)
 181{
 182        if (!git_default_date.len)
 183                datestamp(&git_default_date);
 184        return git_default_date.buf;
 185}
 186
 187void reset_ident_date(void)
 188{
 189        strbuf_reset(&git_default_date);
 190}
 191
 192static int crud(unsigned char c)
 193{
 194        return  c <= 32  ||
 195                c == '.' ||
 196                c == ',' ||
 197                c == ':' ||
 198                c == ';' ||
 199                c == '<' ||
 200                c == '>' ||
 201                c == '"' ||
 202                c == '\\' ||
 203                c == '\'';
 204}
 205
 206/*
 207 * Copy over a string to the destination, but avoid special
 208 * characters ('\n', '<' and '>') and remove crud at the end
 209 */
 210static void strbuf_addstr_without_crud(struct strbuf *sb, const char *src)
 211{
 212        size_t i, len;
 213        unsigned char c;
 214
 215        /* Remove crud from the beginning.. */
 216        while ((c = *src) != 0) {
 217                if (!crud(c))
 218                        break;
 219                src++;
 220        }
 221
 222        /* Remove crud from the end.. */
 223        len = strlen(src);
 224        while (len > 0) {
 225                c = src[len-1];
 226                if (!crud(c))
 227                        break;
 228                --len;
 229        }
 230
 231        /*
 232         * Copy the rest to the buffer, but avoid the special
 233         * characters '\n' '<' and '>' that act as delimiters on
 234         * an identification line. We can only remove crud, never add it,
 235         * so 'len' is our maximum.
 236         */
 237        strbuf_grow(sb, len);
 238        for (i = 0; i < len; i++) {
 239                c = *src++;
 240                switch (c) {
 241                case '\n': case '<': case '>':
 242                        continue;
 243                }
 244                sb->buf[sb->len++] = c;
 245        }
 246        sb->buf[sb->len] = '\0';
 247}
 248
 249/*
 250 * Reverse of fmt_ident(); given an ident line, split the fields
 251 * to allow the caller to parse it.
 252 * Signal a success by returning 0, but date/tz fields of the result
 253 * can still be NULL if the input line only has the name/email part
 254 * (e.g. reading from a reflog entry).
 255 */
 256int split_ident_line(struct ident_split *split, const char *line, int len)
 257{
 258        const char *cp;
 259        size_t span;
 260        int status = -1;
 261
 262        memset(split, 0, sizeof(*split));
 263
 264        split->name_begin = line;
 265        for (cp = line; *cp && cp < line + len; cp++)
 266                if (*cp == '<') {
 267                        split->mail_begin = cp + 1;
 268                        break;
 269                }
 270        if (!split->mail_begin)
 271                return status;
 272
 273        for (cp = split->mail_begin - 2; line <= cp; cp--)
 274                if (!isspace(*cp)) {
 275                        split->name_end = cp + 1;
 276                        break;
 277                }
 278        if (!split->name_end) {
 279                /* no human readable name */
 280                split->name_end = split->name_begin;
 281        }
 282
 283        for (cp = split->mail_begin; cp < line + len; cp++)
 284                if (*cp == '>') {
 285                        split->mail_end = cp;
 286                        break;
 287                }
 288        if (!split->mail_end)
 289                return status;
 290
 291        /*
 292         * Look from the end-of-line to find the trailing ">" of the mail
 293         * address, even though we should already know it as split->mail_end.
 294         * This can help in cases of broken idents with an extra ">" somewhere
 295         * in the email address.  Note that we are assuming the timestamp will
 296         * never have a ">" in it.
 297         *
 298         * Note that we will always find some ">" before going off the front of
 299         * the string, because will always hit the split->mail_end closing
 300         * bracket.
 301         */
 302        for (cp = line + len - 1; *cp != '>'; cp--)
 303                ;
 304
 305        for (cp = cp + 1; cp < line + len && isspace(*cp); cp++)
 306                ;
 307        if (line + len <= cp)
 308                goto person_only;
 309        split->date_begin = cp;
 310        span = strspn(cp, "0123456789");
 311        if (!span)
 312                goto person_only;
 313        split->date_end = split->date_begin + span;
 314        for (cp = split->date_end; cp < line + len && isspace(*cp); cp++)
 315                ;
 316        if (line + len <= cp || (*cp != '+' && *cp != '-'))
 317                goto person_only;
 318        split->tz_begin = cp;
 319        span = strspn(cp + 1, "0123456789");
 320        if (!span)
 321                goto person_only;
 322        split->tz_end = split->tz_begin + 1 + span;
 323        return 0;
 324
 325person_only:
 326        split->date_begin = NULL;
 327        split->date_end = NULL;
 328        split->tz_begin = NULL;
 329        split->tz_end = NULL;
 330        return 0;
 331}
 332
 333static const char *env_hint =
 334N_("\n"
 335   "*** Please tell me who you are.\n"
 336   "\n"
 337   "Run\n"
 338   "\n"
 339   "  git config --global user.email \"you@example.com\"\n"
 340   "  git config --global user.name \"Your Name\"\n"
 341   "\n"
 342   "to set your account\'s default identity.\n"
 343   "Omit --global to set the identity only in this repository.\n"
 344   "\n");
 345
 346const char *fmt_ident(const char *name, const char *email,
 347                      const char *date_str, int flag)
 348{
 349        static struct strbuf ident = STRBUF_INIT;
 350        int strict = (flag & IDENT_STRICT);
 351        int want_date = !(flag & IDENT_NO_DATE);
 352        int want_name = !(flag & IDENT_NO_NAME);
 353
 354        if (want_name) {
 355                int using_default = 0;
 356                if (!name) {
 357                        if (strict && ident_use_config_only
 358                            && !(ident_config_given & IDENT_NAME_GIVEN)) {
 359                                fputs(_(env_hint), stderr);
 360                                die("no name was given and auto-detection is disabled");
 361                        }
 362                        name = ident_default_name();
 363                        using_default = 1;
 364                        if (strict && default_name_is_bogus) {
 365                                fputs(_(env_hint), stderr);
 366                                die("unable to auto-detect name (got '%s')", name);
 367                        }
 368                }
 369                if (!*name) {
 370                        struct passwd *pw;
 371                        if (strict) {
 372                                if (using_default)
 373                                        fputs(_(env_hint), stderr);
 374                                die("empty ident name (for <%s>) not allowed", email);
 375                        }
 376                        pw = xgetpwuid_self(NULL);
 377                        name = pw->pw_name;
 378                }
 379        }
 380
 381        if (!email) {
 382                if (strict && ident_use_config_only
 383                    && !(ident_config_given & IDENT_MAIL_GIVEN)) {
 384                        fputs(_(env_hint), stderr);
 385                        die("no email was given and auto-detection is disabled");
 386                }
 387                email = ident_default_email();
 388                if (strict && default_email_is_bogus) {
 389                        fputs(_(env_hint), stderr);
 390                        die("unable to auto-detect email address (got '%s')", email);
 391                }
 392        }
 393
 394        strbuf_reset(&ident);
 395        if (want_name) {
 396                strbuf_addstr_without_crud(&ident, name);
 397                strbuf_addstr(&ident, " <");
 398        }
 399        strbuf_addstr_without_crud(&ident, email);
 400        if (want_name)
 401                        strbuf_addch(&ident, '>');
 402        if (want_date) {
 403                strbuf_addch(&ident, ' ');
 404                if (date_str && date_str[0]) {
 405                        if (parse_date(date_str, &ident) < 0)
 406                                die("invalid date format: %s", date_str);
 407                }
 408                else
 409                        strbuf_addstr(&ident, ident_default_date());
 410        }
 411
 412        return ident.buf;
 413}
 414
 415const char *fmt_name(const char *name, const char *email)
 416{
 417        return fmt_ident(name, email, NULL, IDENT_STRICT | IDENT_NO_DATE);
 418}
 419
 420const char *git_author_info(int flag)
 421{
 422        if (getenv("GIT_AUTHOR_NAME"))
 423                author_ident_explicitly_given |= IDENT_NAME_GIVEN;
 424        if (getenv("GIT_AUTHOR_EMAIL"))
 425                author_ident_explicitly_given |= IDENT_MAIL_GIVEN;
 426        return fmt_ident(getenv("GIT_AUTHOR_NAME"),
 427                         getenv("GIT_AUTHOR_EMAIL"),
 428                         getenv("GIT_AUTHOR_DATE"),
 429                         flag);
 430}
 431
 432const char *git_committer_info(int flag)
 433{
 434        if (getenv("GIT_COMMITTER_NAME"))
 435                committer_ident_explicitly_given |= IDENT_NAME_GIVEN;
 436        if (getenv("GIT_COMMITTER_EMAIL"))
 437                committer_ident_explicitly_given |= IDENT_MAIL_GIVEN;
 438        return fmt_ident(getenv("GIT_COMMITTER_NAME"),
 439                         getenv("GIT_COMMITTER_EMAIL"),
 440                         getenv("GIT_COMMITTER_DATE"),
 441                         flag);
 442}
 443
 444static int ident_is_sufficient(int user_ident_explicitly_given)
 445{
 446#ifndef WINDOWS
 447        return (user_ident_explicitly_given & IDENT_MAIL_GIVEN);
 448#else
 449        return (user_ident_explicitly_given == IDENT_ALL_GIVEN);
 450#endif
 451}
 452
 453int committer_ident_sufficiently_given(void)
 454{
 455        return ident_is_sufficient(committer_ident_explicitly_given);
 456}
 457
 458int author_ident_sufficiently_given(void)
 459{
 460        return ident_is_sufficient(author_ident_explicitly_given);
 461}
 462
 463int git_ident_config(const char *var, const char *value, void *data)
 464{
 465        if (!strcmp(var, "user.useconfigonly")) {
 466                ident_use_config_only = git_config_bool(var, value);
 467                return 0;
 468        }
 469
 470        if (!strcmp(var, "user.name")) {
 471                if (!value)
 472                        return config_error_nonbool(var);
 473                strbuf_reset(&git_default_name);
 474                strbuf_addstr(&git_default_name, value);
 475                committer_ident_explicitly_given |= IDENT_NAME_GIVEN;
 476                author_ident_explicitly_given |= IDENT_NAME_GIVEN;
 477                ident_config_given |= IDENT_NAME_GIVEN;
 478                return 0;
 479        }
 480
 481        if (!strcmp(var, "user.email")) {
 482                if (!value)
 483                        return config_error_nonbool(var);
 484                strbuf_reset(&git_default_email);
 485                strbuf_addstr(&git_default_email, value);
 486                committer_ident_explicitly_given |= IDENT_MAIL_GIVEN;
 487                author_ident_explicitly_given |= IDENT_MAIL_GIVEN;
 488                ident_config_given |= IDENT_MAIL_GIVEN;
 489                return 0;
 490        }
 491
 492        return 0;
 493}
 494
 495static int buf_cmp(const char *a_begin, const char *a_end,
 496                   const char *b_begin, const char *b_end)
 497{
 498        int a_len = a_end - a_begin;
 499        int b_len = b_end - b_begin;
 500        int min = a_len < b_len ? a_len : b_len;
 501        int cmp;
 502
 503        cmp = memcmp(a_begin, b_begin, min);
 504        if (cmp)
 505                return cmp;
 506
 507        return a_len - b_len;
 508}
 509
 510int ident_cmp(const struct ident_split *a,
 511              const struct ident_split *b)
 512{
 513        int cmp;
 514
 515        cmp = buf_cmp(a->mail_begin, a->mail_end,
 516                      b->mail_begin, b->mail_end);
 517        if (cmp)
 518                return cmp;
 519
 520        return buf_cmp(a->name_begin, a->name_end,
 521                       b->name_begin, b->name_end);
 522}