git/connect.c
Jim Meyering 8e0f70033b Avoid unnecessary "if-before-free" tests.
This change removes all obvious useless if-before-free tests.
E.g., it replaces code like this:

        if (some_expression)
                free (some_expression);

with the now-equivalent:

        free (some_expression);

It is equivalent not just because POSIX has required free(NULL)
to work for a long time, but simply because it has worked for
so long that no reasonable porting target fails the test.
Here's some evidence from nearly 1.5 years ago:

    http://www.winehq.org/pipermail/wine-patches/2006-October/031544.html

FYI, the change below was prepared by running the following:

  git ls-files -z | xargs -0 \
  perl -0x3b -pi -e \
    's/\bif\s*\(\s*(\S+?)(?:\s*!=\s*NULL)?\s*\)\s+(free\s*\(\s*\1\s*\))/$2/s'

Note however, that it doesn't handle brace-enclosed blocks like
"if (x) { free (x); }".  But that's ok, since there were none like
that in git sources.

Beware: if you do use the above snippet, note that it can
produce syntactically invalid C code.  That happens when the
affected "if"-statement has a matching "else".
E.g., it would transform this

  if (x)
    free (x);
  else
    foo ();

into this:

  free (x);
  else
    foo ();

There were none of those here, either.

If you're interested in automating detection of the useless
tests, you might like the useless-if-before-free script in gnulib:
[it *does* detect brace-enclosed free statements, and has a --name=S
 option to make it detect free-like functions with different names]

  http://git.sv.gnu.org/gitweb/?p=gnulib.git;a=blob;f=build-aux/useless-if-before-free

Addendum:
  Remove one more (in imap-send.c), spotted by Jean-Luc Herren <jlh@gmx.ch>.

Signed-off-by: Jim Meyering <meyering@redhat.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-22 14:14:40 -08:00

651 lines
14 KiB
C

#include "git-compat-util.h"
#include "cache.h"
#include "pkt-line.h"
#include "quote.h"
#include "refs.h"
#include "run-command.h"
#include "remote.h"
static char *server_capabilities;
static int check_ref(const char *name, int len, unsigned int flags)
{
if (!flags)
return 1;
if (len < 5 || memcmp(name, "refs/", 5))
return 0;
/* Skip the "refs/" part */
name += 5;
len -= 5;
/* REF_NORMAL means that we don't want the magic fake tag refs */
if ((flags & REF_NORMAL) && check_ref_format(name) < 0)
return 0;
/* REF_HEADS means that we want regular branch heads */
if ((flags & REF_HEADS) && !memcmp(name, "heads/", 6))
return 1;
/* REF_TAGS means that we want tags */
if ((flags & REF_TAGS) && !memcmp(name, "tags/", 5))
return 1;
/* All type bits clear means that we are ok with anything */
return !(flags & ~REF_NORMAL);
}
int check_ref_type(const struct ref *ref, int flags)
{
return check_ref(ref->name, strlen(ref->name), flags);
}
/*
* Read all the refs from the other end
*/
struct ref **get_remote_heads(int in, struct ref **list,
int nr_match, char **match,
unsigned int flags)
{
*list = NULL;
for (;;) {
struct ref *ref;
unsigned char old_sha1[20];
static char buffer[1000];
char *name;
int len, name_len;
len = packet_read_line(in, buffer, sizeof(buffer));
if (!len)
break;
if (buffer[len-1] == '\n')
buffer[--len] = 0;
if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
die("protocol error: expected sha/ref, got '%s'", buffer);
name = buffer + 41;
name_len = strlen(name);
if (len != name_len + 41) {
free(server_capabilities);
server_capabilities = xstrdup(name + name_len + 1);
}
if (!check_ref(name, name_len, flags))
continue;
if (nr_match && !path_match(name, nr_match, match))
continue;
ref = alloc_ref(name_len + 1);
hashcpy(ref->old_sha1, old_sha1);
memcpy(ref->name, buffer + 41, name_len + 1);
*list = ref;
list = &ref->next;
}
return list;
}
int server_supports(const char *feature)
{
return server_capabilities &&
strstr(server_capabilities, feature) != NULL;
}
int get_ack(int fd, unsigned char *result_sha1)
{
static char line[1000];
int len = packet_read_line(fd, line, sizeof(line));
if (!len)
die("git-fetch-pack: expected ACK/NAK, got EOF");
if (line[len-1] == '\n')
line[--len] = 0;
if (!strcmp(line, "NAK"))
return 0;
if (!prefixcmp(line, "ACK ")) {
if (!get_sha1_hex(line+4, result_sha1)) {
if (strstr(line+45, "continue"))
return 2;
return 1;
}
}
die("git-fetch_pack: expected ACK/NAK, got '%s'", line);
}
int path_match(const char *path, int nr, char **match)
{
int i;
int pathlen = strlen(path);
for (i = 0; i < nr; i++) {
char *s = match[i];
int len = strlen(s);
if (!len || len > pathlen)
continue;
if (memcmp(path + pathlen - len, s, len))
continue;
if (pathlen > len && path[pathlen - len - 1] != '/')
continue;
*s = 0;
return (i + 1);
}
return 0;
}
enum protocol {
PROTO_LOCAL = 1,
PROTO_SSH,
PROTO_GIT,
};
static enum protocol get_protocol(const char *name)
{
if (!strcmp(name, "ssh"))
return PROTO_SSH;
if (!strcmp(name, "git"))
return PROTO_GIT;
if (!strcmp(name, "git+ssh"))
return PROTO_SSH;
if (!strcmp(name, "ssh+git"))
return PROTO_SSH;
if (!strcmp(name, "file"))
return PROTO_LOCAL;
die("I don't handle protocol '%s'", name);
}
#define STR_(s) # s
#define STR(s) STR_(s)
#ifndef NO_IPV6
static const char *ai_name(const struct addrinfo *ai)
{
static char addr[INET_ADDRSTRLEN];
if ( AF_INET == ai->ai_family ) {
struct sockaddr_in *in;
in = (struct sockaddr_in *)ai->ai_addr;
inet_ntop(ai->ai_family, &in->sin_addr, addr, sizeof(addr));
} else if ( AF_INET6 == ai->ai_family ) {
struct sockaddr_in6 *in;
in = (struct sockaddr_in6 *)ai->ai_addr;
inet_ntop(ai->ai_family, &in->sin6_addr, addr, sizeof(addr));
} else {
strcpy(addr, "(unknown)");
}
return addr;
}
/*
* Returns a connected socket() fd, or else die()s.
*/
static int git_tcp_connect_sock(char *host, int flags)
{
int sockfd = -1, saved_errno = 0;
char *colon, *end;
const char *port = STR(DEFAULT_GIT_PORT);
struct addrinfo hints, *ai0, *ai;
int gai;
int cnt = 0;
if (host[0] == '[') {
end = strchr(host + 1, ']');
if (end) {
*end = 0;
end++;
host++;
} else
end = host;
} else
end = host;
colon = strchr(end, ':');
if (colon) {
*colon = 0;
port = colon + 1;
if (!*port)
port = "<none>";
}
memset(&hints, 0, sizeof(hints));
hints.ai_socktype = SOCK_STREAM;
hints.ai_protocol = IPPROTO_TCP;
if (flags & CONNECT_VERBOSE)
fprintf(stderr, "Looking up %s ... ", host);
gai = getaddrinfo(host, port, &hints, &ai);
if (gai)
die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
if (flags & CONNECT_VERBOSE)
fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
for (ai0 = ai; ai; ai = ai->ai_next) {
sockfd = socket(ai->ai_family,
ai->ai_socktype, ai->ai_protocol);
if (sockfd < 0) {
saved_errno = errno;
continue;
}
if (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
saved_errno = errno;
fprintf(stderr, "%s[%d: %s]: errno=%s\n",
host,
cnt,
ai_name(ai),
strerror(saved_errno));
close(sockfd);
sockfd = -1;
continue;
}
if (flags & CONNECT_VERBOSE)
fprintf(stderr, "%s ", ai_name(ai));
break;
}
freeaddrinfo(ai0);
if (sockfd < 0)
die("unable to connect a socket (%s)", strerror(saved_errno));
if (flags & CONNECT_VERBOSE)
fprintf(stderr, "done.\n");
return sockfd;
}
#else /* NO_IPV6 */
/*
* Returns a connected socket() fd, or else die()s.
*/
static int git_tcp_connect_sock(char *host, int flags)
{
int sockfd = -1, saved_errno = 0;
char *colon, *end;
char *port = STR(DEFAULT_GIT_PORT), *ep;
struct hostent *he;
struct sockaddr_in sa;
char **ap;
unsigned int nport;
int cnt;
if (host[0] == '[') {
end = strchr(host + 1, ']');
if (end) {
*end = 0;
end++;
host++;
} else
end = host;
} else
end = host;
colon = strchr(end, ':');
if (colon) {
*colon = 0;
port = colon + 1;
}
if (flags & CONNECT_VERBOSE)
fprintf(stderr, "Looking up %s ... ", host);
he = gethostbyname(host);
if (!he)
die("Unable to look up %s (%s)", host, hstrerror(h_errno));
nport = strtoul(port, &ep, 10);
if ( ep == port || *ep ) {
/* Not numeric */
struct servent *se = getservbyname(port,"tcp");
if ( !se )
die("Unknown port %s\n", port);
nport = se->s_port;
}
if (flags & CONNECT_VERBOSE)
fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
if (sockfd < 0) {
saved_errno = errno;
continue;
}
memset(&sa, 0, sizeof sa);
sa.sin_family = he->h_addrtype;
sa.sin_port = htons(nport);
memcpy(&sa.sin_addr, *ap, he->h_length);
if (connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
saved_errno = errno;
fprintf(stderr, "%s[%d: %s]: errno=%s\n",
host,
cnt,
inet_ntoa(*(struct in_addr *)&sa.sin_addr),
strerror(saved_errno));
close(sockfd);
sockfd = -1;
continue;
}
if (flags & CONNECT_VERBOSE)
fprintf(stderr, "%s ",
inet_ntoa(*(struct in_addr *)&sa.sin_addr));
break;
}
if (sockfd < 0)
die("unable to connect a socket (%s)", strerror(saved_errno));
if (flags & CONNECT_VERBOSE)
fprintf(stderr, "done.\n");
return sockfd;
}
#endif /* NO_IPV6 */
static void git_tcp_connect(int fd[2], char *host, int flags)
{
int sockfd = git_tcp_connect_sock(host, flags);
fd[0] = sockfd;
fd[1] = dup(sockfd);
}
static char *git_proxy_command;
static const char *rhost_name;
static int rhost_len;
static int git_proxy_command_options(const char *var, const char *value)
{
if (!strcmp(var, "core.gitproxy")) {
const char *for_pos;
int matchlen = -1;
int hostlen;
if (git_proxy_command)
return 0;
if (!value)
return config_error_nonbool(var);
/* [core]
* ;# matches www.kernel.org as well
* gitproxy = netcatter-1 for kernel.org
* gitproxy = netcatter-2 for sample.xz
* gitproxy = netcatter-default
*/
for_pos = strstr(value, " for ");
if (!for_pos)
/* matches everybody */
matchlen = strlen(value);
else {
hostlen = strlen(for_pos + 5);
if (rhost_len < hostlen)
matchlen = -1;
else if (!strncmp(for_pos + 5,
rhost_name + rhost_len - hostlen,
hostlen) &&
((rhost_len == hostlen) ||
rhost_name[rhost_len - hostlen -1] == '.'))
matchlen = for_pos - value;
else
matchlen = -1;
}
if (0 <= matchlen) {
/* core.gitproxy = none for kernel.org */
if (matchlen == 4 &&
!memcmp(value, "none", 4))
matchlen = 0;
git_proxy_command = xmemdupz(value, matchlen);
}
return 0;
}
return git_default_config(var, value);
}
static int git_use_proxy(const char *host)
{
rhost_name = host;
rhost_len = strlen(host);
git_proxy_command = getenv("GIT_PROXY_COMMAND");
git_config(git_proxy_command_options);
rhost_name = NULL;
return (git_proxy_command && *git_proxy_command);
}
static void git_proxy_connect(int fd[2], char *host)
{
const char *port = STR(DEFAULT_GIT_PORT);
char *colon, *end;
const char *argv[4];
struct child_process proxy;
if (host[0] == '[') {
end = strchr(host + 1, ']');
if (end) {
*end = 0;
end++;
host++;
} else
end = host;
} else
end = host;
colon = strchr(end, ':');
if (colon) {
*colon = 0;
port = colon + 1;
}
argv[0] = git_proxy_command;
argv[1] = host;
argv[2] = port;
argv[3] = NULL;
memset(&proxy, 0, sizeof(proxy));
proxy.argv = argv;
proxy.in = -1;
proxy.out = -1;
if (start_command(&proxy))
die("cannot start proxy %s", argv[0]);
fd[0] = proxy.out; /* read from proxy stdout */
fd[1] = proxy.in; /* write to proxy stdin */
}
#define MAX_CMD_LEN 1024
char *get_port(char *host)
{
char *end;
char *p = strchr(host, ':');
if (p) {
strtol(p+1, &end, 10);
if (*end == '\0') {
*p = '\0';
return p+1;
}
}
return NULL;
}
static struct child_process no_fork;
/*
* This returns a dummy child_process if the transport protocol does not
* need fork(2), or a struct child_process object if it does. Once done,
* finish the connection with finish_connect() with the value returned from
* this function (it is safe to call finish_connect() with NULL to support
* the former case).
*
* If it returns, the connect is successful; it just dies on errors (this
* will hopefully be changed in a libification effort, to return NULL when
* the connection failed).
*/
struct child_process *git_connect(int fd[2], const char *url_orig,
const char *prog, int flags)
{
char *url = xstrdup(url_orig);
char *host, *path = url;
char *end;
int c;
struct child_process *conn;
enum protocol protocol = PROTO_LOCAL;
int free_path = 0;
char *port = NULL;
const char **arg;
struct strbuf cmd;
/* Without this we cannot rely on waitpid() to tell
* what happened to our children.
*/
signal(SIGCHLD, SIG_DFL);
host = strstr(url, "://");
if(host) {
*host = '\0';
protocol = get_protocol(url);
host += 3;
c = '/';
} else {
host = url;
c = ':';
}
if (host[0] == '[') {
end = strchr(host + 1, ']');
if (end) {
*end = 0;
end++;
host++;
} else
end = host;
} else
end = host;
path = strchr(end, c);
if (path) {
if (c == ':') {
protocol = PROTO_SSH;
*path++ = '\0';
}
} else
path = end;
if (!path || !*path)
die("No path specified. See 'man git-pull' for valid url syntax");
/*
* null-terminate hostname and point path to ~ for URL's like this:
* ssh://host.xz/~user/repo
*/
if (protocol != PROTO_LOCAL && host != url) {
char *ptr = path;
if (path[1] == '~')
path++;
else {
path = xstrdup(ptr);
free_path = 1;
}
*ptr = '\0';
}
/*
* Add support for ssh port: ssh://host.xy:<port>/...
*/
if (protocol == PROTO_SSH && host != url)
port = get_port(host);
if (protocol == PROTO_GIT) {
/* These underlying connection commands die() if they
* cannot connect.
*/
char *target_host = xstrdup(host);
if (git_use_proxy(host))
git_proxy_connect(fd, host);
else
git_tcp_connect(fd, host, flags);
/*
* Separate original protocol components prog and path
* from extended components with a NUL byte.
*/
packet_write(fd[1],
"%s %s%chost=%s%c",
prog, path, 0,
target_host, 0);
free(target_host);
free(url);
if (free_path)
free(path);
return &no_fork;
}
conn = xcalloc(1, sizeof(*conn));
strbuf_init(&cmd, MAX_CMD_LEN);
strbuf_addstr(&cmd, prog);
strbuf_addch(&cmd, ' ');
sq_quote_buf(&cmd, path);
if (cmd.len >= MAX_CMD_LEN)
die("command line too long");
conn->in = conn->out = -1;
conn->argv = arg = xcalloc(6, sizeof(*arg));
if (protocol == PROTO_SSH) {
const char *ssh = getenv("GIT_SSH");
if (!ssh) ssh = "ssh";
*arg++ = ssh;
if (port) {
*arg++ = "-p";
*arg++ = port;
}
*arg++ = host;
}
else {
/* remove these from the environment */
const char *env[] = {
ALTERNATE_DB_ENVIRONMENT,
DB_ENVIRONMENT,
GIT_DIR_ENVIRONMENT,
GIT_WORK_TREE_ENVIRONMENT,
GRAFT_ENVIRONMENT,
INDEX_ENVIRONMENT,
NULL
};
conn->env = env;
*arg++ = "sh";
*arg++ = "-c";
}
*arg++ = cmd.buf;
*arg = NULL;
if (start_command(conn))
die("unable to fork");
fd[0] = conn->out; /* read from child's stdout */
fd[1] = conn->in; /* write to child's stdin */
strbuf_release(&cmd);
free(url);
if (free_path)
free(path);
return conn;
}
int finish_connect(struct child_process *conn)
{
int code;
if (!conn || conn == &no_fork)
return 0;
code = finish_command(conn);
free(conn->argv);
free(conn);
return code;
}