/* * Network Block Device - server * * Copyright 1996-1998 Pavel Machek, distribute under GPL * * Copyright 2001-2004 Wouter Verhelst * Copyright 2002 Anton Altaparmakov * * Version 1.0 - hopefully 64-bit-clean * Version 1.1 - merging enhancements from Josh Parsons, * Version 1.2 - autodetect size of block devices, thanx to Peter T. Breuer" * Version 1.5 - can compile on Unix systems that don't have 64 bit integer * type, or don't have 64 bit file offsets by defining FS_32BIT * in compile options for nbd-server *only*. This can be done * with make FSCHOICE=-DFS_32BIT nbd-server. (I don't have the * original autoconf input file, or I would make it a configure * option.) Ken Yap . * Version 1.6 - fix autodetection of block device size and really make 64 bit * clean on 32 bit machines. Anton Altaparmakov * Version 2.0 - Version synchronised with client * Version 2.1 - Reap zombie client processes when they exit. Removed * (uncommented) the _IO magic, it's no longer necessary. Wouter * Verhelst * Version 2.2 - Auto switch to read-only mode (usefull for floppies). * Version 2.3 - Fixed code so that Large File Support works. This * removes the FS_32BIT compile-time directive; define * _FILE_OFFSET_BITS=64 and _LARGEFILE_SOURCE if you used to be * using FS_32BIT. This will allow you to use files >2GB instead of * having to use the -m option. Wouter Verhelst * Version 2.4 - Added code to keep track of children, so that we can * properly kill them from initscripts. Add a call to daemon(), * so that processes don't think they have to wait for us, which is * interesting for initscripts as well. Wouter Verhelst * * Version 2.5 - Bugfix release: forgot to reset child_arraysize to * zero after fork()ing, resulting in nbd-server going berserk * when it receives a signal with at least one child open. Wouter * Verhelst * 10/10/2003 - Added socket option SO_KEEPALIVE (sf.net bug 819235); * rectified type of mainloop::size_host (sf.net bugs 814435 and * 817385); close the PID file after writing to it, so that the * daemon can actually be found. Wouter Verhelst * * 10/10/2003 - Size of the data "size_host" was wrong and so was not * correctly put in network endianness. Many types were corrected * (size_t and off_t instead of int). * Version 2.6 - Some code cleanup. * Version 2.7 - Better build system. * 11/02/2004 - Doxygenified the source, modularized it a bit. Needs a * lot more work, but this is a start. Wouter Verhelst * */ /* Includes LFS defines, which defines behaviours of some of the following * headers, so must come before those */ #include "lfs.h" #include #include #include #include /* wait */ #ifdef HAVE_SYS_IOCTL_H #include #endif #include #ifdef HAVE_SYS_MOUNT_H #include /* For BLKGETSIZE */ #endif #include /* sigaction */ #include #include /* sockaddr_in, htons, in_addr */ #include /* hostent, gethostby*, getservby* */ #include #include #include #include #include #include #include #include #include #include #include #include /* used in cliserv.h, so must come first */ #define MY_NAME "nbd_server" #include "cliserv.h" /** how much space for child PIDs we have by default. Dynamically allocated, and will be realloc()ed if out of space, so this should probably be fair for most situations. */ #define DEFAULT_CHILD_ARRAY 256 /** Logging macros, now nothing goes to syslog unless you say ISSERVER */ #ifdef ISSERVER #define msg2(a,b) syslog(a,b) #define msg3(a,b,c) syslog(a,b,c) #define msg4(a,b,c,d) syslog(a,b,c,d) #else #define msg2(a,b) g_message(b) #define msg3(a,b,c) g_message(b,c) #define msg4(a,b,c,d) g_message(b,c,d) #endif /* Debugging macros */ //#define DODBG #ifdef DODBG #define DEBUG( a ) printf( a ) #define DEBUG2( a,b ) printf( a,b ) #define DEBUG3( a,b,c ) printf( a,b,c ) #else #define DEBUG( a ) #define DEBUG2( a,b ) #define DEBUG3( a,b,c ) #endif #ifndef PACKAGE_VERSION #define PACKAGE_VERSION "" #endif /** * The highest value a variable of type off_t can reach. **/ /* This is starting to get ugly. If someone knows a better way to find * the maximum value of a signed type *without* relying on overflow * (doing so breaks on 64bit architectures), that would be nice. * * Actually, do we need this at all? Can't we just say '0 is autodetect', and * live with it? Or better yet, use an extra flag, or so? * Answer: yes, we need it, as the hunksize is defined to this when the * multiple file thingy isn't used. */ #define OFFT_MAX (((((off_t)1)<<((sizeof(off_t)-1)*8))-1)<<7)+127 #define LINELEN 256 /**< Size of static buffer used to read the authorization file (yuck) */ #define BUFSIZE (1024*1024) /**< Size of buffer that can hold requests */ #define GIGA (1*1024*1024*1024) /**< 1 Gigabyte. Used as hunksize when doing the multiple file thingy. @todo: make this a configuration option. */ #define DIFFPAGESIZE 4096 /**< diff file uses those chunks */ #define F_READONLY 1 /**< flag to tell us a file is readonly */ #define F_MULTIFILE 2 /**< flag to tell us a file is exported using -m */ #define F_COPYONWRITE 4 /**< flag to tell us a file is exported using copyonwrite */ #define F_AUTOREADONLY 8 /**< flag to tell us a file is set to autoreadonly */ GHashTable *children; char pidfname[256]; /**< name of our PID file */ char default_authname[] = "/etc/nbd_server.allow"; /**< default name of allow file */ /** * Variables associated with a server. **/ typedef struct { char* exportname; /**< (unprocessed) filename of the file we're exporting */ off_t hunksize; /**< size of a hunk of an exported file */ off_t expected_size; /**< size of the exported file as it was told to us through configuration */ unsigned int port; /**< port we're exporting this file at */ char* authname; /**< filename of the authorization file */ int flags; /**< flags associated with this exported file */ unsigned int timeout;/**< how long a connection may be idle (0=forever) */ int socket; /**< The socket of this server. */ } SERVER; /** * Variables associated with a client socket. **/ typedef struct { off_t exportsize; /**< size of the file we're exporting */ char *clientname; /**< peer */ char *exportname; /**< (processed) filename of the file we're exporting */ int export[1024]; /**< array of filedescriptors of exported files; only the first is actually used unless we're doing the multiple file option */ int net; /**< The actual client socket */ SERVER *server; /**< The server this client is getting data from */ char* difffilename; /**< filename of the copy-on-write file, if any */ int difffile; /**< filedescriptor of copyonwrite file. @todo shouldn't this be an array too? (cfr export) Or make -m and -c mutually exclusive */ u32 difffilelen; /**< number of pages in difffile */ u32 *difmap; /**< see comment on the global difmap for this one */ } CLIENT; /** * Check whether a client is allowed to connect. Works with an authorization * file which contains one line per machine, no wildcards. * * @param name IP address of client trying to connect (in human-readable form) * @return 0 - authorization refused, 1 - OK **/ int authorized_client(CLIENT *opts) { FILE *f ; char line[LINELEN]; if ((f=fopen(opts->server->authname,"r"))==NULL) { msg4(LOG_INFO,"Can't open authorization file %s (%s).", opts->server->authname,strerror(errno)) ; return 1 ; } while (fgets(line,LINELEN,f)!=NULL) { if (strncmp(line,opts->clientname,strlen(opts->clientname))==0) { fclose(f); return 1; } } fclose(f) ; return 0 ; } /** * Read data from a file descriptor into a buffer * * @param f a file descriptor * @param buf a buffer * @param len the number of bytes to be read **/ inline void readit(int f, void *buf, size_t len) { ssize_t res; while (len > 0) { DEBUG("*"); if ((res = read(f, buf, len)) <= 0) err("Read failed: %m"); len -= res; buf += res; } } /** * Write data from a buffer into a filedescriptor * * @param f a file descriptor * @param buf a buffer containing data * @param len the number of bytes to be written **/ inline void writeit(int f, void *buf, size_t len) { ssize_t res; while (len > 0) { DEBUG("+"); if ((res = write(f, buf, len)) <= 0) err("Send failed: %m"); len -= res; buf += res; } } /** * Print out a message about how to use nbd-server. Split out to a separate * function so that we can call it from multiple places */ void usage() { printf("This is nbd-server version " VERSION "\n"); printf("Usage: port file_to_export [size][kKmM] [-l authorize_file] [-r] [-m] [-c] [-a timeout_sec]\n" "\t-r|--read-only\t\tread only\n" "\t-m|--multi-file\t\tmultiple file\n" "\t-c|--copy-on-write\tcopy on write\n" "\t-l|--authorize-file\tfile with list of hosts that are allowed to\n\t\t\t\tconnect.\n" "\t-a|--idle-time\t\tmaximum idle seconds; server terminates when\n\t\t\t\tidle time exceeded\n\n" "\tif port is set to 0, stdin is used (for running from inetd)\n" "\tif file_to_export contains '%%s', it is substituted with the IP\n" "\t\taddress of the machine trying to connect\n" ); } /** * Parse the command line. * * @todo getopt() is a great thing, and easy to use. Also, we want to * create a configuration file which nbd-server will read. Maybe do (as in, * parse) that here. * * @param argc the argc argument to main() * @param argv the argv argument to main() **/ SERVER* cmdline(int argc, char *argv[]) { int i=0; int c; struct option long_options[] = { {"read-only", no_argument, NULL, 'r'}, {"multi-file", no_argument, NULL, 'm'}, {"copy-on-write", no_argument, NULL, 'c'}, {"authorize-file", required_argument, NULL, 'l'}, {"idle-time", required_argument, NULL, 'a'}, {0,0,0,0} }; SERVER *serve; serve=g_malloc(sizeof(SERVER)); serve->hunksize=OFFT_MAX; while((c=getopt_long(argc, argv, "a:cl:mr", long_options, &i))>=0) { switch (c) { case 'r': serve->flags |= F_READONLY; break; case 'm': serve->flags |= F_MULTIFILE; serve->hunksize = 1*GIGA; serve->authname = default_authname; break; case 'c': serve->flags |=F_COPYONWRITE; break; case 'l': serve->authname=optarg; break; case 'a': serve->timeout=strtol(optarg, NULL, 0); break; default: usage(); exit(0); break; } } /* What's left: the port to export, the name of the to be exported * file, and, optionally, the size of the file, in that order. */ if(++i>=argc) { usage(); exit(0); } serve->port=strtol(argv[i], NULL, 0); if(++i>=argc) { usage(); exit(0); } serve->exportname = argv[i]; if(++iexpected_size = es; } return serve; } /** * Signal handler for SIGCHLD * @param s the signal we're handling (must be SIGCHLD, or something * is severely wrong) **/ void sigchld_handler(int s) { int* status=NULL; int* i; pid_t pid; while((pid=wait(status)) > 0) { if(WIFEXITED(status)) { msg3(LOG_INFO, "Child exited with %d", WEXITSTATUS(status)); } i=g_hash_table_lookup(children, &pid); if(!i) { msg3(LOG_INFO, "SIGCHLD received for an unknown child with PID %ld", (long)pid); } else { DEBUG2("Removing %d from the list of children", pid); g_hash_table_remove(children, &pid); } } } /** * Kill a child. Called from sigterm_handler::g_hash_table_foreach. * * @param key the key * @param value the value corresponding to the above key * @param user_data a pointer which we always set to 1, so that we know what * will happen next. **/ void killchild(gpointer key, gpointer value, gpointer user_data) { pid_t *pid=value; int *parent=user_data; kill(*pid, SIGTERM); *parent=1; } /** * Handle SIGTERM and dispatch it to our children * @param s the signal we're handling (must be SIGTERM, or something * is severely wrong). **/ void sigterm_handler(int s) { int parent=0; g_hash_table_foreach(children, killchild, &parent); if(parent) { unlink(pidfname); } exit(0); } /** * Detect the size of a file. * * @param export An open filedescriptor * @return the size of the file, or OFFT_MAX if detection was * impossible. **/ off_t size_autodetect(int export) { off_t es; u32 es32; struct stat stat_buf; int error; #ifdef HAVE_SYS_MOUNT_H #ifdef HAVE_SYS_IOCTL_H #ifdef BLKGETSIZE DEBUG("looking for export size with ioctl BLKGETSIZE\n"); if (!ioctl(export, BLKGETSIZE, &es32) && es32) { es = (off_t)es32 * (off_t)512; return es; } #endif /* BLKGETSIZE */ #endif /* HAVE_SYS_IOCTL_H */ #endif /* HAVE_SYS_MOUNT_H */ DEBUG("looking for export size with fstat\n"); stat_buf.st_size = 0; error = fstat(export, &stat_buf); if (!error) { if(stat_buf.st_size > 0) return (off_t)stat_buf.st_size; } else { err("fstat failed: %m"); } DEBUG("looking for export size with lseek SEEK_END\n"); es = lseek(export, (off_t)0, SEEK_END); if (es > ((off_t)0)) { return es; } else { DEBUG2("lseek failed: %d", errno==EBADF?1:(errno==ESPIPE?2:(errno==EINVAL?3:4))); } err("Could not find size of exported block device: %m"); return OFFT_MAX; } /** * seek to a position in a file, with error handling. * @param handle a filedescriptor * @param a position to seek to * @todo get rid of this; lastpoint is a global variable right now, but it * shouldn't be. If we pass it on as a parameter, that makes things a *lot* * easier. **/ void myseek(int handle,off_t a) { if (lseek(handle, a, SEEK_SET) < 0) { err("Can not seek locally!\n"); } } /** * Write an amount of bytes at a given offset to the right file. This * abstracts the write-side of the multiple file option. * * @param a The offset where the write should start * @param buf The buffer to write from * @param len The length of buf * @return The number of bytes actually written, or -1 in case of an error **/ int rawexpwrite(off_t a, char *buf, size_t len, CLIENT *client) { ssize_t res; myseek(client->export[(int)a/client->server->hunksize], a%client->server->hunksize); res = write(client->export[(int)((off_t)a/(off_t)(client->server->hunksize))], buf, len); return (res < 0 || (size_t)res != len); } /** * Read an amount of bytes at a given offset from the right file. This * abstracts the read-side of the multiple files option. * * @param a The offset where the read should start * @param buf A buffer to read into * @param len The size of buf * @return The number of bytes actually read, or -1 in case of an * error. **/ int rawexpread(off_t a, char *buf, size_t len, CLIENT *client) { ssize_t res; myseek(client->export[(int)a/client->server->hunksize], a%client->server->hunksize); res = read(client->export[(int)a/client->server->hunksize], buf, len); return (res < 0 || (size_t)res != len); } /** * Read an amount of bytes at a given offset from the right file. This * abstracts the read-side of the copyonwrite stuff, and calls * rawexpread() with the right parameters to do the actual work. * @param a The offset where the read should start * @param buf A buffer to read into * @param len The size of buf * @return The number of bytes actually read, or -1 in case of an error **/ int expread(off_t a, char *buf, size_t len, CLIENT *client) { off_t rdlen, offset; off_t mapcnt, mapl, maph, pagestart; if (!(client->server->flags & F_COPYONWRITE)) return rawexpread(a, buf, len, client); DEBUG3("Asked to read %d bytes at %Lu.\n", len, (unsigned long long)a); mapl=a/DIFFPAGESIZE; maph=(a+len-1)/DIFFPAGESIZE; for (mapcnt=mapl;mapcnt<=maph;mapcnt++) { pagestart=mapcnt*DIFFPAGESIZE; offset=a-pagestart; rdlen=(0difmap[mapcnt]!=(u32)(-1)) { /* the block is already there */ DEBUG3("Page %Lu is at %lu\n", (unsigned long long)mapcnt, (unsigned long)(client->difmap[mapcnt])); myseek(client->difffile, client->difmap[mapcnt]*DIFFPAGESIZE+offset); if (read(client->difffile, buf, rdlen) != rdlen) return -1; } else { /* the block is not there */ DEBUG2("Page %Lu is not here, we read the original one\n", (unsigned long long)mapcnt); return rawexpread(a, buf, rdlen, client); } len-=rdlen; a+=rdlen; buf+=rdlen; } return 0; } /** * Write an amount of bytes at a given offset to the right file. This * abstracts the write-side of the copyonwrite option, and calls * rawexpwrite() with the right parameters to do the actual work. * * @param a The offset where the write should start * @param buf The buffer to write from * @param len The length of buf * @return The number of bytes actually written, or -1 in case of an error **/ int expwrite(off_t a, char *buf, size_t len, CLIENT *client) { char pagebuf[DIFFPAGESIZE]; off_t mapcnt,mapl,maph; off_t wrlen,rdlen; off_t pagestart; off_t offset; if (!(client->server->flags & F_COPYONWRITE)) return(rawexpwrite(a,buf,len, client)); DEBUG3("Asked to write %d bytes at %Lu.\n", len, (unsigned long long)a); mapl=a/DIFFPAGESIZE ; maph=(a+len-1)/DIFFPAGESIZE ; for (mapcnt=mapl;mapcnt<=maph;mapcnt++) { pagestart=mapcnt*DIFFPAGESIZE ; offset=a-pagestart ; wrlen=(0difmap[mapcnt]!=(u32)(-1)) { /* the block is already there */ DEBUG3("Page %Lu is at %lu\n", (unsigned long long)mapcnt, (unsigned long)(client->difmap[mapcnt])) ; myseek(client->difffile, client->difmap[mapcnt]*DIFFPAGESIZE+offset); if (write(client->difffile, buf, wrlen) != wrlen) return -1 ; } else { /* the block is not there */ myseek(client->difffile,client->difffilelen*DIFFPAGESIZE) ; client->difmap[mapcnt]=client->difffilelen++ ; DEBUG3("Page %Lu is not here, we put it at %lu\n", (unsigned long long)mapcnt, (unsigned long)(client->difmap[mapcnt])); rdlen=DIFFPAGESIZE ; if (rdlen+pagestart%(client->server->hunksize) > (client->server->hunksize)) rdlen=client->server->hunksize - (pagestart%client->server->hunksize); if (rawexpread(pagestart, pagebuf, rdlen, client)) return -1; memcpy(pagebuf+offset,buf,wrlen) ; if (write(client->difffile, pagebuf, DIFFPAGESIZE) != DIFFPAGESIZE) return -1; } len-=wrlen ; a+=wrlen ; buf+=wrlen ; } return 0; } /** * Do the initial negotiation. * * @param net A socket to do the negotiation over **/ void negotiate(CLIENT *client) { char zeros[300]; u64 size_host; memset(zeros, 0, 290); if (write(client->net, INIT_PASSWD, 8) < 0) err("Negotiation failed: %m"); cliserv_magic = htonll(cliserv_magic); if (write(client->net, &cliserv_magic, sizeof(cliserv_magic)) < 0) err("Negotiation failed: %m"); size_host = htonll((u64)(client->exportsize)); if (write(client->net, &size_host, 8) < 0) err("Negotiation failed: %m"); if (write(client->net, zeros, 128) < 0) err("Negotiation failed: %m"); } /** sending macro. */ #define SEND(net,reply) writeit( net, &reply, sizeof( reply )); /** error macro. */ #define ERROR(client,reply) { reply.error = htonl(-1); SEND(client->net,reply); reply.error = 0; } /** * Serve a file to a single client. * * @todo This beast needs to be split up in many tiny little manageable * pieces. Preferably with a chainsaw. * * @param net A network socket, connected to an nbd client * @return never **/ int mainloop(CLIENT *client) { struct nbd_request request; struct nbd_reply reply; gboolean go_on=TRUE; #ifdef DODBG int i = 0; #endif negotiate(client); DEBUG("Entering request loop!\n"); reply.magic = htonl(NBD_REPLY_MAGIC); reply.error = 0; while (go_on) { char buf[BUFSIZE]; size_t len; #ifdef DODBG i++; printf("%d: ", i); #endif if (client->server->timeout) alarm(client->server->timeout); readit(client->net, &request, sizeof(request)); request.from = ntohll(request.from); request.type = ntohl(request.type); if (request.type==NBD_CMD_DISC) { msg2(LOG_INFO, "Disconnect request received."); if (client->difmap) g_free(client->difmap) ; if (client->difffile>=0) { close(client->difffile); unlink(client->difffilename); } go_on=FALSE; continue; } len = ntohl(request.len); if (request.magic != htonl(NBD_REQUEST_MAGIC)) err("Not enough magic."); if (len > BUFSIZE) err("Request too big!"); #ifdef DODBG printf("%s from %Lu (%Lu) len %d, ", request.type ? "WRITE" : "READ", (unsigned long long)request.from, (unsigned long long)request.from / 512, len); #endif memcpy(reply.handle, request.handle, sizeof(reply.handle)); if ((request.from + len) > (OFFT_MAX)) { DEBUG("[Number too large!]"); ERROR(client, reply); continue; } if (((ssize_t)((off_t)request.from + len) > client->exportsize) || ((client->server->flags & F_READONLY) && request.type)) { DEBUG("[RANGE!]"); ERROR(client, reply); continue; } if (request.type==NBD_CMD_WRITE) { DEBUG("wr: net->buf, "); readit(client->net, buf, len); DEBUG("buf->exp, "); if ((client->server->flags & F_AUTOREADONLY) || expwrite(request.from, buf, len, client)) { DEBUG("Write failed: %m" ); ERROR(client, reply); continue; } SEND(client->net, reply); DEBUG("OK!\n"); continue; } /* READ */ DEBUG("exp->buf, "); if (expread(request.from, buf + sizeof(struct nbd_reply), len, client)) { DEBUG("Read failed: %m"); ERROR(client, reply); continue; } DEBUG("buf->net, "); memcpy(buf, &reply, sizeof(struct nbd_reply)); writeit(client->net, buf, len + sizeof(struct nbd_reply)); DEBUG("OK!\n"); } return 0; } /** * Split a single exportfile into multiple ones, if that was asked. * @return 0 on success, -1 on failure * @param client information on the client which we want to split **/ int splitexport(CLIENT* client) { off_t i; for (i=0; iexportsize; i+=client->server->hunksize) { gchar *tmpname; if(client->server->flags & F_MULTIFILE) { tmpname=g_strdup_printf("%s.%d", client->exportname, (int)(i/client->server->hunksize)); } else { tmpname=g_strdup(client->exportname); } DEBUG2( "Opening %s\n", tmpname ); if ((client->export[ i/ client->server->hunksize ] = open(tmpname, (client->server->flags & F_READONLY) ? O_RDONLY : O_RDWR)) == -1) { /* Read WRITE ACCESS was requested by media is only read only */ client->server->flags |= F_AUTOREADONLY; client->server->flags |= F_READONLY; if ((client->export[i/client->server->hunksize] = open(tmpname, O_RDONLY)) == -1) err("Could not open exported file: %m"); } g_free(tmpname); } if (client->server->flags & F_COPYONWRITE) { snprintf(client->difffilename, 1024, "%s-%s-%d.diff",client->exportname,client->clientname, (int)getpid()) ; client->difffilename[1023]='\0'; msg3(LOG_INFO,"About to create map and diff file %s",client->difffilename) ; client->difffile=open(client->difffilename,O_RDWR | O_CREAT | O_TRUNC,0600) ; if (client->difffile<0) err("Could not create diff file (%m)") ; if ((client->difmap=calloc(client->exportsize/DIFFPAGESIZE,sizeof(u32)))==NULL) err("Could not allocate memory") ; for (i=0;iexportsize/DIFFPAGESIZE;i++) client->difmap[i]=(u32)-1 ; } return 0; } /** * Serve a connection. * * @todo allow for multithreading, perhaps use libevent. Not just yet, though; * follow the road map. * * @param net A network socket connected to an nbd client **/ void serveconnection(CLIENT *client) { splitexport(client); if (!client->server->expected_size) { client->exportsize = size_autodetect(client->export[0]); } else { /* Perhaps we should check first. Not now. */ client->exportsize = client->server->expected_size; } if (client->exportsize > OFFT_MAX) { /* uhm, well... In a parallel universe, this *might* be * possible... */ err("Size of exported file is too big\n"); } else { msg3(LOG_INFO, "size of exported file/device is %Lu", (unsigned long long)client->exportsize); } setmysockopt(client->net); mainloop(client); } /** * Find the name of the file we have to serve. This will use g_strdup_printf * to put the IP address of the client inside a filename containing * "%s". That name is then written to client->exportname. * * @param net A socket connected to an nbd client * @param client information about the client. The IP address in human-readable * format will be written to a new char* buffer, the address of which will be * stored in client->clientname. **/ void set_peername(int net, CLIENT *client) { struct sockaddr_in addrin; int addrinlen = sizeof( addrin ); char *peername ; if (getpeername(net, (struct sockaddr *) &addrin, (socklen_t *)&addrinlen) < 0) err("getsockname failed: %m"); peername = inet_ntoa(addrin.sin_addr); client->exportname=g_strdup_printf(client->server->exportname, peername); msg4(LOG_INFO, "connect from %s, assigned file is %s", peername, client->exportname); client->clientname=g_strdup(peername); } /** * Destroy a pid_t* * @param data a pointer to pid_t which should be freed **/ void destroy_pid_t(gpointer data) { g_free(data); } /** * Go daemon (unless we specified at compile time that we didn't want this) * @param serve the first server of our configuration. If its port is zero, * then do not daemonize, because we're doing inetd then. **/ #if !defined(NODAEMON) && !defined(NOFORK) void daemonize(SERVER* serve) { FILE*pidf; if((serve->port)) { if(daemon(0,0)<0) { err("daemon"); } snprintf(pidfname, sizeof(char)*255, "/var/run/nbd-server.%d.pid", serve->port); pidf=fopen(pidfname, "w"); if(pidf) { fprintf(pidf,"%d", (int)getpid()); fclose(pidf); } else { perror("fopen"); fprintf(stderr, "Not fatal; continuing"); } } } #else #define daemonize(serve) #endif /* !defined(NODAEMON) && !defined(NOFORK) */ /** * Connect a server's socket. * * @todo modularize this giant beast. Preferably with a chainsaw. Also, * it has no business starting mainloop(), through serveconnection(); it * should connect, and be done with it. * * @param serve the server we want to connect. **/ void setup_serve(SERVER* serve) { struct sockaddr_in addrin; struct sigaction sa; int addrinlen = sizeof(addrin); #ifndef sun int yes=1; #else char yes='1'; #endif /* sun */ if ((serve->socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) err("socket: %m"); /* lose the pesky "Address already in use" error message */ if (setsockopt(serve->socket,SOL_SOCKET,SO_REUSEADDR,&yes,sizeof(int)) == -1) { err("setsockopt SO_REUSEADDR"); } if (setsockopt(serve->socket,SOL_SOCKET,SO_KEEPALIVE,&yes,sizeof(int)) == -1) { err("setsockopt SO_KEEPALIVE"); } DEBUG("Waiting for connections... bind, "); addrin.sin_family = AF_INET; addrin.sin_port = htons(serve->port); addrin.sin_addr.s_addr = 0; if (bind(serve->socket, (struct sockaddr *) &addrin, addrinlen) < 0) err("bind: %m"); DEBUG("listen, "); if (listen(serve->socket, 1) < 0) err("listen: %m"); sa.sa_handler = sigchld_handler; sigemptyset(&sa.sa_mask); sa.sa_flags = SA_RESTART; if(sigaction(SIGCHLD, &sa, NULL) == -1) err("sigaction: %m"); sa.sa_handler = sigterm_handler; sigemptyset(&sa.sa_mask); sa.sa_flags = SA_RESTART; if(sigaction(SIGTERM, &sa, NULL) == -1) err("sigaction: %m"); children=g_hash_table_new_full(g_int_hash, g_int_equal, NULL, destroy_pid_t); } /** * Loop through the available servers, and serve them. * * Actually, right now we only handle one server. Will change that for * 2.9. **/ int serveloop(SERVER* serve) { struct sockaddr_in addrin; socklen_t addrinlen=sizeof(addrin); for(;;) { CLIENT *client; int net; pid_t *pid; DEBUG("accept, "); if ((net = accept(serve->socket, (struct sockaddr *) &addrin, &addrinlen)) < 0) err("accept: %m"); client = g_malloc(sizeof(CLIENT)); client->server=serve; client->exportsize=OFFT_MAX; client->net=net; set_peername(net, client); if (!authorized_client(client)) { msg2(LOG_INFO,"Unauthorized client") ; close(net) ; continue ; } msg2(LOG_INFO,"Authorized client") ; pid=g_malloc(sizeof(pid_t)); #ifndef NOFORK if ((*pid=fork())<0) { msg3(LOG_INFO,"Could not fork (%s)",strerror(errno)) ; close(net) ; continue ; } if (*pid>0) { /* parent */ close(net); g_hash_table_insert(children, pid, pid); continue; } /* child */ g_hash_table_destroy(children); close(serve->socket) ; #endif // NOFORK msg2(LOG_INFO,"Starting to serve") ; serveconnection(client); } } /** * Main entry point... **/ int main(int argc, char *argv[]) { SERVER* serve; GArray* servers; if (sizeof( struct nbd_request )!=28) { fprintf(stderr,"Bad size of structure. Alignment problems?\n"); exit(-1) ; } logging(); serve=cmdline(argc, argv); servers=g_array_new(TRUE, FALSE, sizeof(SERVER*)); if (!(serve->port)) { CLIENT *client; #ifndef ISSERVER /* You really should define ISSERVER if you're going to use * inetd mode, but if you don't, closing stdout and stderr * (which inetd had connected to the client socket) will let it * work. */ close(1); close(2); open("/dev/null", O_WRONLY); open("/dev/null", O_WRONLY); #endif client=g_malloc(sizeof(CLIENT)); client->server=serve; client->net=0; client->exportsize=OFFT_MAX; set_peername(0,client); serveconnection(client); return 0; } daemonize(serve); setup_serve(serve); serveloop(serve); return 0 ; }