git/ident.c
Patrick Steinhardt 32f9929109 ident: add casts for fallback name and GECOS
In `xgetpwuid_self()`, we return a fallback identity when it was not
possible to look up the current identity. This fallback identity needs
to be internal and must never be written to by the calles as specified
by getpwuid(3P). As both the `pw_name` and `pw_gecos` fields are marked
as non-constant though, it will cause a warning to assign constant
strings to them once compiling with `-Wwrite-strings`.

Add explicit casts to avoid the warning.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-07 10:30:51 -07:00

733 lines
18 KiB
C

/*
* ident.c
*
* create git identifier lines of the form "name <email> date"
*
* Copyright (C) 2005 Linus Torvalds
*/
#include "git-compat-util.h"
#include "ident.h"
#include "config.h"
#include "date.h"
#include "gettext.h"
#include "mailmap.h"
#include "strbuf.h"
static struct strbuf git_default_name = STRBUF_INIT;
static struct strbuf git_default_email = STRBUF_INIT;
static struct strbuf git_default_date = STRBUF_INIT;
static struct strbuf git_author_name = STRBUF_INIT;
static struct strbuf git_author_email = STRBUF_INIT;
static struct strbuf git_committer_name = STRBUF_INIT;
static struct strbuf git_committer_email = STRBUF_INIT;
static int default_email_is_bogus;
static int default_name_is_bogus;
static int ident_use_config_only;
#define IDENT_NAME_GIVEN 01
#define IDENT_MAIL_GIVEN 02
#define IDENT_ALL_GIVEN (IDENT_NAME_GIVEN|IDENT_MAIL_GIVEN)
static int committer_ident_explicitly_given;
static int author_ident_explicitly_given;
static int ident_config_given;
#ifdef NO_GECOS_IN_PWENT
#define get_gecos(ignored) "&"
#else
#define get_gecos(struct_passwd) ((struct_passwd)->pw_gecos)
#endif
static struct passwd *xgetpwuid_self(int *is_bogus)
{
struct passwd *pw;
errno = 0;
pw = getpwuid(getuid());
if (!pw) {
static struct passwd fallback;
fallback.pw_name = (char *) "unknown";
#ifndef NO_GECOS_IN_PWENT
fallback.pw_gecos = (char *) "Unknown";
#endif
pw = &fallback;
if (is_bogus)
*is_bogus = 1;
}
return pw;
}
static void copy_gecos(const struct passwd *w, struct strbuf *name)
{
char *src;
/* Traditionally GECOS field had office phone numbers etc, separated
* with commas. Also & stands for capitalized form of the login name.
*/
for (src = get_gecos(w); *src && *src != ','; src++) {
int ch = *src;
if (ch != '&')
strbuf_addch(name, ch);
else {
/* Sorry, Mr. McDonald... */
strbuf_addch(name, toupper(*w->pw_name));
strbuf_addstr(name, w->pw_name + 1);
}
}
}
static int add_mailname_host(struct strbuf *buf)
{
FILE *mailname;
struct strbuf mailnamebuf = STRBUF_INIT;
mailname = fopen_or_warn("/etc/mailname", "r");
if (!mailname)
return -1;
if (strbuf_getline(&mailnamebuf, mailname) == EOF) {
if (ferror(mailname))
warning_errno("cannot read /etc/mailname");
strbuf_release(&mailnamebuf);
fclose(mailname);
return -1;
}
/* success! */
strbuf_addbuf(buf, &mailnamebuf);
strbuf_release(&mailnamebuf);
fclose(mailname);
return 0;
}
static int canonical_name(const char *host, struct strbuf *out)
{
int status = -1;
#ifndef NO_IPV6
struct addrinfo hints, *ai;
memset (&hints, '\0', sizeof (hints));
hints.ai_flags = AI_CANONNAME;
if (!getaddrinfo(host, NULL, &hints, &ai)) {
if (ai && ai->ai_canonname && strchr(ai->ai_canonname, '.')) {
strbuf_addstr(out, ai->ai_canonname);
status = 0;
}
freeaddrinfo(ai);
}
#else
struct hostent *he = gethostbyname(host);
if (he && strchr(he->h_name, '.')) {
strbuf_addstr(out, he->h_name);
status = 0;
}
#endif /* NO_IPV6 */
return status;
}
static void add_domainname(struct strbuf *out, int *is_bogus)
{
char buf[HOST_NAME_MAX + 1];
if (xgethostname(buf, sizeof(buf))) {
warning_errno("cannot get host name");
strbuf_addstr(out, "(none)");
*is_bogus = 1;
return;
}
if (strchr(buf, '.'))
strbuf_addstr(out, buf);
else if (canonical_name(buf, out) < 0) {
strbuf_addf(out, "%s.(none)", buf);
*is_bogus = 1;
}
}
static void copy_email(const struct passwd *pw, struct strbuf *email,
int *is_bogus)
{
/*
* Make up a fake email address
* (name + '@' + hostname [+ '.' + domainname])
*/
strbuf_addstr(email, pw->pw_name);
strbuf_addch(email, '@');
if (!add_mailname_host(email))
return; /* read from "/etc/mailname" (Debian) */
add_domainname(email, is_bogus);
}
const char *ident_default_name(void)
{
if (!(ident_config_given & IDENT_NAME_GIVEN) && !git_default_name.len) {
copy_gecos(xgetpwuid_self(&default_name_is_bogus), &git_default_name);
strbuf_trim(&git_default_name);
}
return git_default_name.buf;
}
const char *ident_default_email(void)
{
if (!(ident_config_given & IDENT_MAIL_GIVEN) && !git_default_email.len) {
const char *email = getenv("EMAIL");
if (email && email[0]) {
strbuf_addstr(&git_default_email, email);
committer_ident_explicitly_given |= IDENT_MAIL_GIVEN;
author_ident_explicitly_given |= IDENT_MAIL_GIVEN;
} else if ((email = query_user_email()) && email[0]) {
strbuf_addstr(&git_default_email, email);
free((char *)email);
} else
copy_email(xgetpwuid_self(&default_email_is_bogus),
&git_default_email, &default_email_is_bogus);
strbuf_trim(&git_default_email);
}
return git_default_email.buf;
}
static const char *ident_default_date(void)
{
if (!git_default_date.len)
datestamp(&git_default_date);
return git_default_date.buf;
}
void reset_ident_date(void)
{
strbuf_reset(&git_default_date);
}
static int crud(unsigned char c)
{
return c <= 32 ||
c == ',' ||
c == ':' ||
c == ';' ||
c == '<' ||
c == '>' ||
c == '"' ||
c == '\\' ||
c == '\'';
}
static int has_non_crud(const char *str)
{
for (; *str; str++) {
if (!crud(*str))
return 1;
}
return 0;
}
/*
* Copy over a string to the destination, but avoid special
* characters ('\n', '<' and '>') and remove crud at the end
*/
static void strbuf_addstr_without_crud(struct strbuf *sb, const char *src)
{
size_t i, len;
unsigned char c;
/* Remove crud from the beginning.. */
while ((c = *src) != 0) {
if (!crud(c))
break;
src++;
}
/* Remove crud from the end.. */
len = strlen(src);
while (len > 0) {
c = src[len-1];
if (!crud(c))
break;
--len;
}
/*
* Copy the rest to the buffer, but avoid the special
* characters '\n' '<' and '>' that act as delimiters on
* an identification line. We can only remove crud, never add it,
* so 'len' is our maximum.
*/
strbuf_grow(sb, len);
for (i = 0; i < len; i++) {
c = *src++;
switch (c) {
case '\n': case '<': case '>':
continue;
}
sb->buf[sb->len++] = c;
}
sb->buf[sb->len] = '\0';
}
/*
* Reverse of fmt_ident(); given an ident line, split the fields
* to allow the caller to parse it.
* Signal a success by returning 0, but date/tz fields of the result
* can still be NULL if the input line only has the name/email part
* (e.g. reading from a reflog entry).
*/
int split_ident_line(struct ident_split *split, const char *line, int len)
{
const char *cp;
size_t span;
int status = -1;
memset(split, 0, sizeof(*split));
split->name_begin = line;
for (cp = line; *cp && cp < line + len; cp++)
if (*cp == '<') {
split->mail_begin = cp + 1;
break;
}
if (!split->mail_begin)
return status;
for (cp = split->mail_begin - 2; line <= cp; cp--)
if (!isspace(*cp)) {
split->name_end = cp + 1;
break;
}
if (!split->name_end) {
/* no human readable name */
split->name_end = split->name_begin;
}
for (cp = split->mail_begin; cp < line + len; cp++)
if (*cp == '>') {
split->mail_end = cp;
break;
}
if (!split->mail_end)
return status;
/*
* Look from the end-of-line to find the trailing ">" of the mail
* address, even though we should already know it as split->mail_end.
* This can help in cases of broken idents with an extra ">" somewhere
* in the email address. Note that we are assuming the timestamp will
* never have a ">" in it.
*
* Note that we will always find some ">" before going off the front of
* the string, because will always hit the split->mail_end closing
* bracket.
*/
for (cp = line + len - 1; *cp != '>'; cp--)
;
for (cp = cp + 1; cp < line + len && isspace(*cp); cp++)
;
if (line + len <= cp)
goto person_only;
split->date_begin = cp;
span = strspn(cp, "0123456789");
if (!span)
goto person_only;
split->date_end = split->date_begin + span;
for (cp = split->date_end; cp < line + len && isspace(*cp); cp++)
;
if (line + len <= cp || (*cp != '+' && *cp != '-'))
goto person_only;
split->tz_begin = cp;
span = strspn(cp + 1, "0123456789");
if (!span)
goto person_only;
split->tz_end = split->tz_begin + 1 + span;
return 0;
person_only:
split->date_begin = NULL;
split->date_end = NULL;
split->tz_begin = NULL;
split->tz_end = NULL;
return 0;
}
/*
* Returns the difference between the new and old length of the ident line.
*/
static ssize_t rewrite_ident_line(const char *person, size_t len,
struct strbuf *buf,
struct string_list *mailmap)
{
size_t namelen, maillen;
const char *name;
const char *mail;
struct ident_split ident;
if (split_ident_line(&ident, person, len))
return 0;
mail = ident.mail_begin;
maillen = ident.mail_end - ident.mail_begin;
name = ident.name_begin;
namelen = ident.name_end - ident.name_begin;
if (map_user(mailmap, &mail, &maillen, &name, &namelen)) {
struct strbuf namemail = STRBUF_INIT;
size_t newlen;
strbuf_addf(&namemail, "%.*s <%.*s>",
(int)namelen, name, (int)maillen, mail);
strbuf_splice(buf, ident.name_begin - buf->buf,
ident.mail_end - ident.name_begin + 1,
namemail.buf, namemail.len);
newlen = namemail.len;
strbuf_release(&namemail);
return newlen - (ident.mail_end - ident.name_begin);
}
return 0;
}
void apply_mailmap_to_header(struct strbuf *buf, const char **header,
struct string_list *mailmap)
{
size_t buf_offset = 0;
if (!mailmap)
return;
for (;;) {
const char *person, *line;
size_t i;
int found_header = 0;
line = buf->buf + buf_offset;
if (!*line || *line == '\n')
return; /* End of headers */
for (i = 0; header[i]; i++)
if (skip_prefix(line, header[i], &person)) {
const char *endp = strchrnul(person, '\n');
found_header = 1;
buf_offset += endp - line;
buf_offset += rewrite_ident_line(person, endp - person, buf, mailmap);
break;
}
if (!found_header) {
buf_offset = strchrnul(line, '\n') - buf->buf;
if (buf->buf[buf_offset] == '\n')
buf_offset++;
}
}
}
static void ident_env_hint(enum want_ident whose_ident)
{
switch (whose_ident) {
case WANT_AUTHOR_IDENT:
fputs(_("Author identity unknown\n"), stderr);
break;
case WANT_COMMITTER_IDENT:
fputs(_("Committer identity unknown\n"), stderr);
break;
default:
break;
}
fputs(_("\n"
"*** Please tell me who you are.\n"
"\n"
"Run\n"
"\n"
" git config --global user.email \"you@example.com\"\n"
" git config --global user.name \"Your Name\"\n"
"\n"
"to set your account\'s default identity.\n"
"Omit --global to set the identity only in this repository.\n"
"\n"), stderr);
}
const char *fmt_ident(const char *name, const char *email,
enum want_ident whose_ident, const char *date_str, int flag)
{
static int index;
static struct strbuf ident_pool[2] = { STRBUF_INIT, STRBUF_INIT };
int strict = (flag & IDENT_STRICT);
int want_date = !(flag & IDENT_NO_DATE);
int want_name = !(flag & IDENT_NO_NAME);
struct strbuf *ident = &ident_pool[index];
index = (index + 1) % ARRAY_SIZE(ident_pool);
if (!email) {
if (whose_ident == WANT_AUTHOR_IDENT && git_author_email.len)
email = git_author_email.buf;
else if (whose_ident == WANT_COMMITTER_IDENT && git_committer_email.len)
email = git_committer_email.buf;
}
if (!email) {
if (strict && ident_use_config_only
&& !(ident_config_given & IDENT_MAIL_GIVEN)) {
ident_env_hint(whose_ident);
die(_("no email was given and auto-detection is disabled"));
}
email = ident_default_email();
if (strict && default_email_is_bogus) {
ident_env_hint(whose_ident);
die(_("unable to auto-detect email address (got '%s')"), email);
}
}
if (want_name) {
int using_default = 0;
if (!name) {
if (whose_ident == WANT_AUTHOR_IDENT && git_author_name.len)
name = git_author_name.buf;
else if (whose_ident == WANT_COMMITTER_IDENT &&
git_committer_name.len)
name = git_committer_name.buf;
}
if (!name) {
if (strict && ident_use_config_only
&& !(ident_config_given & IDENT_NAME_GIVEN)) {
ident_env_hint(whose_ident);
die(_("no name was given and auto-detection is disabled"));
}
name = ident_default_name();
using_default = 1;
if (strict && default_name_is_bogus) {
ident_env_hint(whose_ident);
die(_("unable to auto-detect name (got '%s')"), name);
}
}
if (!*name) {
struct passwd *pw;
if (strict) {
if (using_default)
ident_env_hint(whose_ident);
die(_("empty ident name (for <%s>) not allowed"), email);
}
pw = xgetpwuid_self(NULL);
name = pw->pw_name;
}
if (strict && !has_non_crud(name))
die(_("name consists only of disallowed characters: %s"), name);
}
strbuf_reset(ident);
if (want_name) {
strbuf_addstr_without_crud(ident, name);
strbuf_addstr(ident, " <");
}
strbuf_addstr_without_crud(ident, email);
if (want_name)
strbuf_addch(ident, '>');
if (want_date) {
strbuf_addch(ident, ' ');
if (date_str && date_str[0]) {
if (parse_date(date_str, ident) < 0)
die(_("invalid date format: %s"), date_str);
}
else
strbuf_addstr(ident, ident_default_date());
}
return ident->buf;
}
const char *fmt_name(enum want_ident whose_ident)
{
char *name = NULL;
char *email = NULL;
switch (whose_ident) {
case WANT_BLANK_IDENT:
break;
case WANT_AUTHOR_IDENT:
name = getenv("GIT_AUTHOR_NAME");
email = getenv("GIT_AUTHOR_EMAIL");
break;
case WANT_COMMITTER_IDENT:
name = getenv("GIT_COMMITTER_NAME");
email = getenv("GIT_COMMITTER_EMAIL");
break;
}
return fmt_ident(name, email, whose_ident, NULL,
IDENT_STRICT | IDENT_NO_DATE);
}
const char *git_author_info(int flag)
{
if (getenv("GIT_AUTHOR_NAME"))
author_ident_explicitly_given |= IDENT_NAME_GIVEN;
if (getenv("GIT_AUTHOR_EMAIL"))
author_ident_explicitly_given |= IDENT_MAIL_GIVEN;
return fmt_ident(getenv("GIT_AUTHOR_NAME"),
getenv("GIT_AUTHOR_EMAIL"),
WANT_AUTHOR_IDENT,
getenv("GIT_AUTHOR_DATE"),
flag);
}
const char *git_committer_info(int flag)
{
if (getenv("GIT_COMMITTER_NAME"))
committer_ident_explicitly_given |= IDENT_NAME_GIVEN;
if (getenv("GIT_COMMITTER_EMAIL"))
committer_ident_explicitly_given |= IDENT_MAIL_GIVEN;
return fmt_ident(getenv("GIT_COMMITTER_NAME"),
getenv("GIT_COMMITTER_EMAIL"),
WANT_COMMITTER_IDENT,
getenv("GIT_COMMITTER_DATE"),
flag);
}
static int ident_is_sufficient(int user_ident_explicitly_given)
{
#ifndef WINDOWS
return (user_ident_explicitly_given & IDENT_MAIL_GIVEN);
#else
return (user_ident_explicitly_given == IDENT_ALL_GIVEN);
#endif
}
int committer_ident_sufficiently_given(void)
{
return ident_is_sufficient(committer_ident_explicitly_given);
}
int author_ident_sufficiently_given(void)
{
return ident_is_sufficient(author_ident_explicitly_given);
}
static int set_ident(const char *var, const char *value)
{
if (!strcmp(var, "author.name")) {
if (!value)
return config_error_nonbool(var);
strbuf_reset(&git_author_name);
strbuf_addstr(&git_author_name, value);
author_ident_explicitly_given |= IDENT_NAME_GIVEN;
ident_config_given |= IDENT_NAME_GIVEN;
return 0;
}
if (!strcmp(var, "author.email")) {
if (!value)
return config_error_nonbool(var);
strbuf_reset(&git_author_email);
strbuf_addstr(&git_author_email, value);
author_ident_explicitly_given |= IDENT_MAIL_GIVEN;
ident_config_given |= IDENT_MAIL_GIVEN;
return 0;
}
if (!strcmp(var, "committer.name")) {
if (!value)
return config_error_nonbool(var);
strbuf_reset(&git_committer_name);
strbuf_addstr(&git_committer_name, value);
committer_ident_explicitly_given |= IDENT_NAME_GIVEN;
ident_config_given |= IDENT_NAME_GIVEN;
return 0;
}
if (!strcmp(var, "committer.email")) {
if (!value)
return config_error_nonbool(var);
strbuf_reset(&git_committer_email);
strbuf_addstr(&git_committer_email, value);
committer_ident_explicitly_given |= IDENT_MAIL_GIVEN;
ident_config_given |= IDENT_MAIL_GIVEN;
return 0;
}
if (!strcmp(var, "user.name")) {
if (!value)
return config_error_nonbool(var);
strbuf_reset(&git_default_name);
strbuf_addstr(&git_default_name, value);
committer_ident_explicitly_given |= IDENT_NAME_GIVEN;
author_ident_explicitly_given |= IDENT_NAME_GIVEN;
ident_config_given |= IDENT_NAME_GIVEN;
return 0;
}
if (!strcmp(var, "user.email")) {
if (!value)
return config_error_nonbool(var);
strbuf_reset(&git_default_email);
strbuf_addstr(&git_default_email, value);
committer_ident_explicitly_given |= IDENT_MAIL_GIVEN;
author_ident_explicitly_given |= IDENT_MAIL_GIVEN;
ident_config_given |= IDENT_MAIL_GIVEN;
return 0;
}
return 0;
}
int git_ident_config(const char *var, const char *value,
const struct config_context *ctx UNUSED,
void *data UNUSED)
{
if (!strcmp(var, "user.useconfigonly")) {
ident_use_config_only = git_config_bool(var, value);
return 0;
}
return set_ident(var, value);
}
static void set_env_if(const char *key, const char *value, int *given, int bit)
{
if ((*given & bit) || getenv(key))
return; /* nothing to do */
setenv(key, value, 0);
*given |= bit;
}
void prepare_fallback_ident(const char *name, const char *email)
{
set_env_if("GIT_AUTHOR_NAME", name,
&author_ident_explicitly_given, IDENT_NAME_GIVEN);
set_env_if("GIT_AUTHOR_EMAIL", email,
&author_ident_explicitly_given, IDENT_MAIL_GIVEN);
set_env_if("GIT_COMMITTER_NAME", name,
&committer_ident_explicitly_given, IDENT_NAME_GIVEN);
set_env_if("GIT_COMMITTER_EMAIL", email,
&committer_ident_explicitly_given, IDENT_MAIL_GIVEN);
}
static int buf_cmp(const char *a_begin, const char *a_end,
const char *b_begin, const char *b_end)
{
int a_len = a_end - a_begin;
int b_len = b_end - b_begin;
int min = a_len < b_len ? a_len : b_len;
int cmp;
cmp = memcmp(a_begin, b_begin, min);
if (cmp)
return cmp;
return a_len - b_len;
}
int ident_cmp(const struct ident_split *a,
const struct ident_split *b)
{
int cmp;
cmp = buf_cmp(a->mail_begin, a->mail_end,
b->mail_begin, b->mail_end);
if (cmp)
return cmp;
return buf_cmp(a->name_begin, a->name_end,
b->name_begin, b->name_end);
}